The reason 1 pilot goes around may also be the reason the next pilot goes around, The second pilot would like to know before hand whether the runway is safe to land on.

For example if it is wind related he can delay landing until it dies down.

If it is debris related then the tower can dispatch a cleaning crew.

Pilots are not required to give a reason for a go-around, just to say that they are going around.

A go-around is a busy time for the pilot(s) of the aircraft - power, flaps, trim, must be set, gear raised in some cases.

The pilot needs to aviate first.

The tower wants to know why the go-around was initiated by the pilot as it may be relevant for safety and/or operations.

If the pilot is going around because of a botched approach then that won't impact other flights, however if there is a problem with the aircraft the tower can organize emergency resources.

If the go-around is due to a situation on the ground then the tower can look to clear that up.

The only reason for a go-around is that the pilot or ATC thinks that landing is not safe or possible for this approach.

When the pilot does that, they follow the 5 Ups memory aid ( Power Up, Nose Up, Gear Up, Flaps Up, Speak Up ).

You can see that by the time a pilot is ready to inform ATC about go-around, he is already going around.

Commonly, when ATC requests a go-around, it is if there is an unsafe condition such as an aircraft, vehicle, or object on the runway.

When the pilot decides to go-around, it can be one of the following reasons : the aircraft is not lined up it is not configured properly for a safe landing an aircraft, vehicle or other object has not cleared the runway no landing clearance was received (at a towered field)

the landing gear is not properly extended a dangerous meteorological condition is experienced on final approach (e.g., poor visibility, excessive cross-winds, windshear, etc.)

excessive energy (too high or too fast) or any other unsafe condition is detected

Short answer: because first you're disrupting the traffic pattern (especially at larger airports that don't use a circular pattern and coordinate direct approaches instead) and the tower will want an explanation, and second because if there is a problem outside the cockpit causing you to execute the missed approach, other craft might have the same problem, and if the tower knows about it they can take steps to resolve it, or at least advise other incoming craft.

I've only got about 300 hours logged

but I have not once been asked WHY I am going around.

However if you "intend" to do a touch-and-go or an abort

/go around

you must inform them, because it's their job to know where every aircraft is going.

I usually tell the tower before takeoff

I'll be flying a "closed pattern" if just practicing TnGs.

Makes it much easier for ATC.

When I intend to stop, I will say landing "Full Stop" when turning final.

But, as Farhan said, if anything is off on approach or you bounce on touchdown, miss the touchdown zone, wind starts kicking your ass or if ANYTHING isn't perfect, it's full throttle, flaps up once +ROC, and figure out what u did wrong.

The tower can wait, they are all in there watching, laughing at your pathetic attempt anyway.

If something is wrong, do insist on priority access!

POC is in charge after all.

My alternator 172SP died on climbout once

and I didn't say a thing, just rushed to mid field and dove vertical out of downwind pattern, slipping the hell out of it to slow her down.

Per protocol, I didn't say a word to ATC until I was clear of the runway.

But always be nice to the ATC.

Fantastic guys that would do ANYTHING to keep their pilots safe.

The FAA/NTSB tho

.... they are the best reason to keep your mouth shut unless you are out of options!

Question: Why does the tower ask pilots what the reason is for a go-around? This seems to be standard for commercial flights.

Why are pilots asked to provide a reason for a go-around?

The tower needs to know why a pilot has initiated a go around because it may affect other air traffic especialy at busy aairports that do not operate a circular pattern. If there is a safety issue, other planes need to be informed and the tower would want to take steps to resolve it.

Pilots are asked to provide a reason for a go-around because it may affect other pilots coming in to land. Moreover, the tower needs to be aware of any problems so that it can take action if necessary.

The cause of the go-around may also affect other aircraft coming in to land.

The tower needs to know the reason for the go-around so that they can take appropriate action if needed.


In the early years of the jet age, which followed closely on the introduction of pressurized hulls , there was much fear of stresses specifically in the area of the window openings due to the loss of two DeHavilland Comets .

Subsequent Comet hulls had different shaped, rounded, smaller windows and that trend continued in other pressurized, typically jet-powered, aircraft.

Only with modern CAD systems and new materials knowledge could windows be made larger again.

The newest aircraft designs reflect that progress.

I think engineering knowledge is an important factor, going from the time of the first 737 to the A380, there was a huge development in engineering techniques.

Better material knowledge, more advanced modeling methods (such as Finite Elements) and better knowledge of structural optimization have improved the situation.

Especially with windows, where a lot is happening due to stress concentrations, this improved knowledge makes a difference.

This means that bigger windows might still lead to an increase in weight, but there will be a less severe weight penalty than the same windows using B737 age techniques.

It is the use of composite materials in the aircraft body structure that has enabled larger windows.

Metals are a crystalline structure that over time tend to fracture along crystal structure defects.

Some key areas (e.g. turbine blades in the engine) are actually created by growing a single crystal to obtain higher failure points.

This is not possible over a structure the size of the aircraft frame.

When an aircraft is at altitude, it is like a pressurised balloon.

its skin is under tension, and when it on the ground, that tension is removed.

This is like constantly flexing a metal paper clip.

The cross sectional area of the aircraft skin that carries this tension is reduced by windows - bigger windows put bigger strain on the airframe structure which tends to concentrate at corners.

making corners rounded helps to spread this stress.

The composite materials used in new planes are fibrous in structure.

This greatly reduces the risks from the repeated flexing, allowing larger windows (and as the rust risk is reduced, cabin air is allowed to be more moist with also aids in flight comfort of passengers)

Let me answer with a car analogy: In most cases, the next car model is larger than the one before.

Similarly, the aircraft manufacturers make the windows a little bigger with every new model, just to have another argument why the new model is better than all the competition.

This costs a little weight, but seems to be worth it for the airlines.

One of the important things I'd like to add to the previous answers is that the old air-crafts used to have smaller windows to accommodate for the rate of cabin depressurization in case of an emergency.

The old airplanes had much smaller windows to control the cabin depressurization rate in case of some emergency (some window actually breaking to cause hull breach).

But with advancement in the design methods and manufacturing process and with the introduction of the newer materials for airplane manufacturing, it has become possible to increase the size of the windows without increasing the risk factor.

In addition to this, creating an ambient atmosphere for the passengers inside the airplane without increasing the cost of the flight has always been a priority.

So, while decreasing the seat spacing to accommodate more passengers is being done to reduce flight cost, the increase in the size of the windows does not have determinal effect on the travel cost, and hence is favored to create a less claustrophobic atmosphere inside the plane.

As well as the advances in engineering, it is worth considering the comfort of the passengers.

It is often thought that the more natural light in the cabin the better the experience for the passengers.

More light increases the feeling of space, and can even reduce the fatigue experienced as a result of air travel.

Whether or not there is much science in this I do not know.

Some Aircraft manufacturers use the window sizes as a big selling point.

Gulfstream aircraft, for example, allow in more light than any comparable aircraft due to their oval shaped windows.

In an attempt to compete Dassault are putting more windows on their newer Falcon 8x and Falcon 5x models.

Both companies have also introduced windows in the galleys in some models (Dassault famously with the 'sky light') as this is typically the darkest and narrowest part of the cabin.

In the cabin configurations most typical in Europe, the galley is at the very front of the cabin and is the first thing you see when you enter the aircraft.

I think it is safe to say that it is much nicer to walk into a bright, airy space than a dark, narrow corridor.

Gulfstream 650 window details: Sixteen large Gulfstream panoramic windows, each 28 by 20.5 inches/71by 52 centimeters, allow abundant sunlight into the cabin, even in thegalley.

Every window has been repositioned higher on the fuselage tomaximize viewing comfort* http://www.gulfstream.com/aircraft/gulfstream-g650 Falcon 5X window & 'skylight' details: Increased natural light does more than improve the view.

It elevatesyour mood and enlarges your perspective.

The 28 large, expansivewindows of the 5X provide unbeatable luminosity.

The Falcon 5X offers an unprecedented direct view of the sky overheadthrough its skylight ceiling window.

This unique window on the skytransforms your perception of space while providing natural light fromabove. http://www.dassaultfalcon.com/en/Aircraft/Models/5X/Pages/overview.aspx

Question: Modern airliners like the Airbus A380 and Boeing 787 have bigger windows than older designs, like the Boeing 737 and Airbus A320.   What factors have led to this change of window size, opposite to the trend of almost every other thing in the interior of the plane becoming smaller in size (like the seats).

What are the factors behind increasing aircraft window sizes?

The huge development in engineering techniques and knowledge of materials have allowed windows to be made bigger. Bigger windows increase the amount of natural light which is thought to improve passenger experience. They also create a feeling of space and may even reduce fatigue. Some airlines use them as a selling point.

There are a couple of different factors behind the increase in window size. One is the advancements made in engineering, including the use of composite materials in the body of the aircraft. Another is the passenger experience - more natural light makes for a more pleasant flying experience.

One of the factors behind increased window sizes is the advancements made in engineering, including the use of composite materials in the body of the aircraft. Window size is used as a selling point by some manufacturers.

The experience of the passenger is a factor. More natural light makes for a more pleasant flying experience.

The size of the windows is used as a selling point by some manufacturers.


Of course yes .

Crosswind landings , like the one in the video you linked, are very common.

In fact, landings with no wind or only headwind are rare.

There are

several techniques pilots are taught during their extensive training to land aircraft when there is crosswind.

The Wikipedia article I referenced above lists them.

Since your question isn't about them, we won't discuss them.

Certainly, extreme weather situation are not very common.

Some parts of the world experience extreme weather more than other areas.

Diverting to other airports is not always an option and in some cases, once an airplane is on the approach, going around becomes impossible .

In the US it is required by law to be trained in cross wind landings.

For large aircraft that require a type rating... §61.31 Type rating requirements, additional training, and authorization requirements... ...

(2) Received a logbook endorsement from an authorized instructor who has found the person proficient in the operation of the aircraft and its systems.

(i)

Normal and crosswind takeoffs and landings ; (ii) Wheel landings (unless the manufacturer has recommended against such landings); and (iii) Go-around procedures.

On a side note cross wind landings are very important since not all airports have 2 runway options.

Some large commercial airports will have 2 crossing runways which will allow you to pick the best one for the days winds (they are usually built to the general prevailing winds in the area).

This does not mean there will be no cross wind

but it does allow you to mitigate it.

Smaller airports may only have a single runway (or 2 parallel runways) which means you have no method of mitigation for the crosswind.

There are even some big airports that are only single runway due to space or geographic restrictions.

It should also be noted that airplanes them selves have a demonstrated cross wind component to which they are tested to be safe to land in a cross wind of said velocity.

This is not necessary a maximum (although it can be) but it is often used as such.

As for how often this happens that is largely a factor of the airport and the local weather.

For example I used to fly out of KPNE

they have 2 runway options (6-24 and 15-33)

they would use what ever was the best runway for the wind that day unless you needed the precision approach on 24.

This made landing there easy (150 x 5000 or 7000 helped as well) as there was never really more than a 15 degree crosswind.

I now fly out of KDYL which is a single runway airstrip that almost always has a crosswind, really keeps you on your toes.

Cross wind approaches are perfectly safe and are not out of the ordinary.

I have seen some people mistake the phrase Uncoordinated Flight as meaning a sideslipped crosswind landing is unsafe which is incorrect.

The plane can be uncoordinated because it is side slipping to the landing which is done deliberately by the pilot.

The answers so far deal with commercial flying, from a recreational perspective pilots are only as well trained as the amount they practice.

Commercial organizations generally train their pilots for crosswind landings in simulators, and they usually fly enough to get real crosswinds often enough to keep in practice.

Private pilots are trained in crosswind techniques in initial training, keeping good crosswind abilities is up to the pilot once they pass their test.

I personally practice crosswind take-offs and landings as often as I can, however I know many pilots who won't fly if there's more than 5 knots across the runway.

Yes, pilots are trained for crosswind landings.

I trained on a Cessna 172 as Paso Robles.

The video was completely normal.

A roll of < 10 degrees is not serious at all, well within a competent pilot's operational abilities.

The news story was written by someone who doesn't fly, thought it looked 'scary' and filled 90 seconds with nonsense, IMO.

I'm a little late to the party, but here is my take.

In that landing I see turbulence

but I don't see an obvious crosswind component.

In any case, dealing with crosswinds is something that happens more often than not when landing (at least at many airports and airfields).

So every single pilot has dealt with this since the very first days of basic training.

As for the wing rocking, correcting an off-level wing is probably the very first thing a student learns when getting acquainted with the aircraft's controls.

It is completely intuitive for every single pilot.

Question: A  YouTube footage  of a KLM Boeing 777 landing at Schiphol airport in the Netherlands is certainly scary as the plane bumps and weaves and rolls from side to side.    Are pilots generally trained to handle such eventualities (or are such landings common in certain regions of the world?) or was everyone involved including the pilot taking a risk in this case without diverting the aircraft to a nearby safe location?

Are pilots generally trained for crosswind landings?

Of course commercial pilots are trained in crosswind landings. In fact in the US this is a legal requirement. In many parts of the world this is a regular climatic condition at airports. Simulator training is also given and working as a pilot, they experience these landings on a regular basis.

Yes, pilots are trained for crosswind landings. This is a legal requirement in the US.

Crosswind landings are safe and they are performed frequently, particularly in parts of the world where extreme weather is more common. Diverting to a nearby location is not always possible.

Commercial pilots tend to get plenty of practice with crosswind landings, whereas private pilots may have to work harder on their ability to land in crosswinds.

Yes, pilots are trained for crosswind landings. This is a legal requirement in the US. Commercial pilots tend to get plenty of practice with crosswind landings, whereas private pilots may have to work harder on their ability to land in crosswinds.

Extreme weather is more common in certain parts of the world.

Diverting to a nearby location may not always be possible.


They still want to get into the low cost segment but want to market themselves differently for better penetration.

You can only present so many images of a brand to customers: You can't show both the super-cheap prices with happy youth on them and posh first class at the same time.

They do not want to tarnish a nice brand by mixing it with a low cost carrier and what that is perceived to entail.

For instance, Germanwings got a somewhat infamous reputation recently, and Lufthansa is probably happy their name was not more frequently used in media.

Low cost is also associated with less good customer service and hidden fees.

Crew are often less well paid, and they are sometimes put under a separate working agreement and company to try to prevent conflicts.

Some legacy carriers have very good pay which is difficult to reduce.

Management does not want to be bound by these when expanding or adjusting their business.

Each case is pretty specific depending on exactly they are trying to do and achieve.

For many American Carriers and Lufthansa, the last one is probably the principle reason.

As mentioned there are lots of branding issues around this

but there are also lots of corporate and legal reasons to do so.

Business Isolation : If you want to start out a bunch of new routes and you are not sure how well they are going to do a large airline

my not want to book that kind of loss or risk having to cover it.

Thus they can incorporate a "new" airline and protect their existing and profitable business interests should the "new" airline go under.

Likewise it also makes it easier, should it be very profitable, to potentially sell it off (or absorb it as well).

Taxes/Fees :

Tax law changes from place to place so this may differ depending on where they are based but if there are different taxes as a result of company size or specific aviation taxes they may be able to take advantage of them by splitting up.

Legal Isolation : I am no lawyer

but I am sure that how ever they set these up

it isolates the parent airline should anything happen to the other carrier.

Image/

Branding

: this has been touched on already but as mentioned you may not want the image that comes with running a low cost brand associated with your luxury brand.

I would imagine this has to do with branding.

Kind of like how some car companies have both "regular" and "premium" brands.

Eg., Chevy v. Cadillac or VW v. Audi, etc etc.

It allows for companies to have a more exclusive version of their product for people who are just the premium, exclusive sorts...

Granted

there are other cost considerations, and other branding considerations, and I could probably sit here and go on for hours with that

but I think it would be a little bit outside of scope.

So, to just give a basic explanation:

Different brands have different associations with them.

Some are seen as premium, exclusive, indulgent.

Others are seen as just hitting the basics.

And some companies will avoid mixing the two just for the sake of brand identity in marketing.

As mentioned in earlier answers, branding and management (pay, collective bargaining agreements, etc.) are certainly two major factors.

And legacy airlines are mindful of the risk to see their profit cannibalised by the new cheap fares so they need to maintain as much segmentation/price discrimination as possible.

Interestingly, the two strategies are not exclusive.

Air France/KLM has several low-cost subsidiaries (Transavia, Transavia-France and HOP!)

but also introduced many low-costs tactics (no meal, surcharge for hold luggage…) on short-haul European routes on both legacy airlines.

The thing is that some elements of the low-cost model (paid refreshments, quick turnaround, routes to cheap airports or use low-cost terminals at major airports, single-class cabin with as many seats as possible, identical aircrafts…) can only be introduced for the whole airplane or even the whole fleet.

And for a highly price-sensitive market segment, merely using some elements of the model to offer lower prices is not enough, you need to go all in to ensure your fares are as low as those of your direct competitors (say Easyjet, not necessarily Ryanair).

A business reason no-one has mentioned yet is the original reason the big names started: Because low cost airlines began flying routes cheaply and created a market If the big names hadn't joined in, all that revenue would have gone to the low cost airlines, who would have grown to the point they could potentially compete in the existing markets, so it was essential that the big players joined in.

It is not possible to run a low cost airline in the structures of a major airline (the cost model is entirely different - passenger demographics, services on board, pre-flight hospitality, additional benefits etc.)

so the only way to do it that makes financial sense is to run it as a separate logical entity.

It has proven to be a difficult change for some of those big airlines, with various attempts at creating budget versions failing, but some have managed to compete successfully.

Question: There are various full service carriers (FSCs) who have a separate low-cost carrier (LCC) subsidiary. For example:   Germanwings  by  Lufthansa  Air India Express  by  Air India  JetKonnect  by  Jet Airways   Why do the FSCs prefer to launch a separate LCC, rather than providing seats at a cheaper rate with reduced comforts within their existing structure?

Why do full service airlines prefer to run a separate low-cost carrier?

Brand and imaging are major factors in large airlines running a separate low-cost airline.  The two types of airline offer very different services and appeal to a different target group. If large airlines did not run a low-cost airline, they would have lost all those customers to other players in the market. Low-cost airlines are typically structured completely differently from major airlines and thus it would be impossible or undesirable to run the two sides as one company.

The main reason seems to be branding. It makes more sense to separate an exclusive brand from a low-cost brand

Management is also a factor. The structures of large airlines do not lend themselves to low-cost models. Separating the companies may be beneficial in terms of salary and taxes. From an industry perspective, it made sense for the larger airlines to become involved in the low-cost segment so that low-cost airlines didn't dominate the market.

It comes down to branding. It makes more sense to separate an exclusive brand from a low-cost brand rather than attempt to combine the two.

Low-cost airlines are associated with lower-quality customer service and hidden costs.

Management is a factor - low-cost airline crew are often less well-paid, and separate companies may help to prevent conflict.

From a tax perspective, it may be beneficial to have two separate companies.

From an industry perspective, it made sense for the larger airlines to become involved in the low-cost segment. If they hadn't, the low-cost airlines may have been able to dominate the market.


The central cargo hold is usually pretty big and open, if cargo was placed in loosely then it might shift in flight which can cause the center of mass to shift or damage the walls of the hold.

Putting them in containers and fixing those down will prevent that.

The containers can also be weighed before hand and their position set to ensure the center of mass ends up where it should be.

With loose cargo the pilot would need to rely on the intuition and experience of the loaders to ensure that they don't put all the heavy stuff on one side.

Loading loose luggage requires that the loader in the cargo hold handles each bag while stacking them.

The hold also needs to be full enough that the luggage can't shift around.

The smaller forward and rear cargo holds (or on smaller planes) can still accommodate loose luggage (or

more precisely they are too small for the containers to fit).

They will also have netting to provide barriers against shifting.

Why is this required to be done?

As far as I know, this is not required by law, it is an operational practice by airlines.

According to Wikipedia "It allows a large quantity of cargo to be bundled into a single unit.

Since this leads to fewer units to load, it saves ground crews time and effort and helps prevent delayed flights.

Why don't they simply keep the luggage in the luggage compartment?

baggage can be loaded into ULDs while the aircraft they are intended for is still in flight.

This reduces turn-around time.

Aircraft only earn money when they are in the air, on the ground they bleed money from the airline's shareholders.

Airlines try to keep aircraft in the air and avoid having them on the ground as much as possible.

Why is loading the luggage piece-by-piece time consuming Because luggage is not of uniform size, shape and strength.

Therefore it is a labour-intensive process not especially amenable to full mechanisation.

It simply takes longer to load 50 (say) randomly shaped objects than it does to load one object of standardised shape and size. at the end, in second photo mentioned there, the luggage is being loaded piece-by-piece.

What is that?

I don't know, but it seems plausible that some passengers are willing to pay for their luggage to be carefully hand loaded.

I.e. first-class.

This allows those passengers to pay for an express boarding process and spend less time in the airport.

Well there are several advantages of loading the luggage in unit load devices (ULDs) such as: In ULD, the luggage suffers much less shock than it would, if left alone.

Else, the incidence of baggage manhandling would increase several times.

We are already losing \$2.58 bn/year due to this.

ULDs lead to better use of aircraft cargo space.

Stacking the luggage one over the other would be a very time consuming and tiring job, and if it is not done, then a lot of cargo space of aircraft would be wasted.

ULDs help prevent this.

ULDs are cost effective.

Compare the cost of 100s people busy in stacking the luggage, and one conveyor belt doing the job.

ULDs are safer, in the way they prevent unauthorized access to the luggage.

And, in the second picture shown there, the luggage is being loaded into luggage hold.

Which has several Pallets/Nets for storing small ammount of luggage.

Usually, they are used to store some small cargo belonging to first class passengers.

Think about the benefits of containerisation.

Ships could take days to unload if they carried many different items like lumber, sacks of corn etc.

Along came containers and now you can unload a ship in hours.

The labour intensive part of loading

/stacking is distributed toward the containers themselves, and thus frees up the expensive capital item such as a ship or plane to be turned around more quickly.

It all makes economic sense.

so is it required?

yes, if you wish to stay competitive and in business it is.

There are some safety and security aspects to containing luggage within containers.

When content leaks, goes bad, or even explodes , the container may serve to limit the damage to other luggage within the aircraft, along with the aircraft itself.

Also, if the airline is feeding flights to other destinations, baggage can be pre-sorted.

For example, a flight into CMB (Colombo, Sri Lanka) is commonly used as a feeder service for onward travel to MLE (Male, Maldives).

If all the MLE-destination bags are separated from the CMB-destination bags at the time of loading and are in their own ULDs, those ULDs can be simply moved into the MLE aircraft, saving the time to offload all bags, re-sort and separate the MLE ones, and then reload.

Question: Luggage is loaded into containers, in Wide Body airliners (as mentioned  here ). Why is this required to be done? Why don't they simply keep the luggage in the luggage compartment? Why is loading the luggage piece-by-piece time consuming, and at the end, in second photo mentioned there, the luggage is being loaded piece-by-piece. What is that?

Why is luggage required to be loaded in containers?

Cargo is loaded onto aircraft in containers for several reasons. Firstly, it prevents the luggage from moving around during the flight, causing the center of mass to shift. Secondly, it localizes and spills or breakages. Thirdly, it provides for a better use of the cargo space. Finally, the luggage itself is protected from the shocks involved with moving around during the flight. Containers are also cost effective and prevent unauthorized access to the luggage.

This not a legal requirement. One of the reasons for placing luggage in containers is so that the weight can be evenly distributed. Its also minimises the risk of damage and means that the cargo space is used more effectively. Using containers is also more cost-effective, less labour-intensive and safer, as it prevents unauthorized access.

Placing luggage in containers ensures that the weight can be evenly distributed.

Loading the luggage piece by piece is more labour-intensive.

Loading the luggage in containers minimises the risk of damage to the luggage and to the aircraft.

Loading the luggage in containers means that the cargo space is used more effectively.

Using containers is safer, as it prevents unauthorized access.


Where would you get the compressed air from?

Jet engines "contain" compressed air because the engine itself compresses it using the energy from burning fuel.

Asking if you could power the engine by that compressed air is like asking if you could power a car engine by the rotation of the gearbox: it's confusing cause and effect.

A typical modern turbofan engine produces about 85% of its thrust from bypass flow, i.e. "compressed air", that never goes through the actual jet core.

However, as others have mentioned, in order to get the compressors spinning and sucking air in to begin with, you still need an energy source of some kind to turn them and, for lack of a better alternative, current designs still rely on jet core flow to turn both sets of turbines and, by extension, their associated compressors.

The engine is compressing air to more efficiently burn fuel.

If you remove the fuel, there is no reason to compress the air.

Other systems that run off of the engine bleed air only do so because it is a convenient source.

The 787 uses a bleedless model that runs off of electric power instead of engine bleed air.

Electric airplanes are certainly an option, but a propeller is a better option than a turbine engine .

You could however keep the duct around the prop .

No.

Air is compressed because we have jetful to run the compressor in the first place.

No fuel, no compressed air (or very very few, from to drag induced by windmilling the engine).

Have a look at https://en.wikipedia.org/wiki/Jet_engine for more informations

A plane with compressed air tanks would also not be possible, as it requires A LOT of air to move an aircraft

In modern aircraft's jet engines (both turbojets and turbofans), compressed air is used: For starting the engine, spooling it up until the shut-off valve is opened and the fuel starts to enter and burn in the combustion chamber; For running auxiliary systems, like de-icing and pressurizing equipments; This is not true for some newer engines like the General Electric's GEnx that use an electric starter or little jet engines (including APUs) and sometimes turboshafts (turboprops).

In aviation it's common to refers to the systems running/producing compressed air as 'pneumatic' systems or 'bleed-air'.

This, for instance, is the part of the overhead panel of a Boeing 737 used to manage pneumatic systems (taken from http://www.b737.org.uk/pneumatics.htm ):

Question: I was just curious because the air is very compressed in the engine and some things do run on compressed air. And what if the engine was powered all by electricity?

Can an engine on a Boeing 737 fly just using compressed air instead of jet fuel?

Jets canot fly using compressed air in place of jet fuel. For an electric plane, a propeller would be a better option than a turbine.

The answer to the question is no because the air is only compressed because there is fuel to power the compressor.

Electricity would be an option but a propellor would be better than a turbine engine.

No. The air is only compressed because there is fuel to power the compressor.

Electricity is an option but a propellor would be better than a turbine engine.


Are you asking about the rear support wheel?

It is for supporting the aircraft and avoiding tilt on the ground.

Image from wikimedia commons.

Autor:

M Radzi Desa

As the aircraft had four engines in the aft, the cg would've been aft too; so they added a tail prop to prevent tilt on ground.

Interestingly, this doesn't seen to be unique for Il-62.

Another aircraft with rear mounted engine, Sud Aviation Caravelle, has something similar to this.

Image from wikimedia commons.

Author: Eduard Marmet

The 'tail prop' is more accurately described as a tail support.

I remember seeing these on Il-62s at Heathrow in the 70s.

They were deployed as the aircraft arrived at the gate, and retracted just before pushback.

Anecdotally, the aircraft had a propensity to tilt backwards and strike the tail on the ground during loading and unloading operations as the CG moved.

The tail support eliminated this possibility.

They're called "tail stands" for planes such as the Cessna Caravan.

During loading and unloading the CG can be tail-heavy enough that the aircraft would otherwise fall back on its tail.

I found an Aircraft Operations Manual for IL-62 and IL-62 M of former GDR carrier Interflug (in German language): http://www.interflug.biz/IL-62%20Flugbetriebsdokumentationen.htm http://www.interflug.biz/Flugzeuge/IL-62/Handbuecher/FZH_Il62.pdf

According to this manual, the "tail prop" supports several functions.

Supporting parked airplane while centre of gravity isn't controlled: The manual requires to extend the tail prop when parking, before opening any door.

Tail prop shall be retracted only after closing all doors and only when centre of gravity is within limits (4.2.5.

No. 2., tab.

Taxi with extended tail prop is allowed, speed limit is 25 km/h.

No. 1)

When towing an empty plane the tail prop must be extended, speed limit is 15 km/h.

No. 2)

Moving the plane backward by utilizing reverse thrust: Tail prop must be extended, speed limit is "walking pace".

No. 4)

U-turn on a narrow runway (min.

45 m) by utilizing reverse thrust: Tail prop must be partly extended.

No. 5,

fig.

The tail prop features two self-steering wheels and a suspension system.

No brakes, no active steering.

It is extended and retracted by an electric motor, backed by a hand crank.

No. 1.3, fig.

Probably, the tail prop is also designed to provide some protection in case of a tail strike (since it's wheels partly remain outside fuselage), but this function isn't mentioned in the manual.

Btw.

, this plane features a 3700 ℓ water tank (just behind the front landing gear bay), for adjusting centre of gravity in some low-load situations.

(4.1.24., 4.3.2.

No. 2.5, fig.

4.1.2/2 item 5)

It's a tail stand -- it prevents the airplane from tipping up and back onto its tailfeathers in a most embarrassing fashion, even if you have to load it back to front or unload it front to back (image from Aerospaceweb's question on landing gear ):

Improvised tail-props were a feature of early, tricycle landing gear, military aircraft.

Grumman's F7F Tigercat, certainly.

There are photos with 55 gallon drums + assorted odds and ends as props, in place, and also photos of unsupported planes sitting with nose-wheels off the ground...

At that point in Grumman's history, nobody would have expected resting the tail on the ground would do any damage to the airplane...

This is a very interesting take on CG vs Clift, in this case while the aircraft is not moving!The wheels are holding the aircraft up.

It would take a relatively small amount of force to tip the plane onto its tail while loading or unloading.

A little like a table with 3 legs instead of 4.

While taking off, the aircraft has to be able to rotate, which means the main gear need to be only slightly aft of the CG when fueled and loaded for flight.

On the ground this creates the potential for it to go "tail dragger" if cargo is removed from the front or added to the back.

Moving people from front to back was actually used in airships to help trim CG.

But it is very, very important to realize this is not done "because engines are heavy" and the designed CG is somehow unsafely aft.

Jet engines are actually (lb weight per lb thrust) much lighter than their piston counterparts.

Aircraft with swept wings who must, by necessity, mount the landing gear closer to the fuselage (or in the fuselage) would have a greater tendency for "ground Clift" issues.

The B52 designers solved this by mounting the wing at a higher AOA than the fuselage and taking off WITHOUT rotating, relying only on speed to lift the aircraft off.

This also fits well in pilot training not to "pull up" a large aircraft, as shear mass would make recovery of precious airspeed difficult, even with lots of excessthrust available.

The "tail pogo" is strictly a safety precaution while passengers, cargo, and fuel are being loaded or unloaded on the ground,

Many smaller turboprops and piston twins use 'tail props' or 'pogo-sticks' as they are known here.

Certainly Twin Otters, BN Islander and Trislanders use them.

Can't comment on the Caravan.

The last one I was son a few weeks ago had floats ;-)

Robert DiGiovanni's response is correct.

While the empty IL62 is a bit tail heavy, once the airplane is laoded with passengers/bags and cargo the CG will be moved forward.

Look at how much longer the fwd fuselage is compared to the aft section, its around 4 times longer!

The MD11 has a similar proportion where the forward fuselage is much longer than the front.

I've done the load-sheet for MD11 freighters and while the empty CG is VERY tail heavy, with a full load the CG is usually at the fwd limit.

Question: I read somewhere that the Ilyushin Il-62 had a "tail prop".  What was this device and why was it needed on this aircraft?

What was the purpose of the "tail prop" on the Ilyushin Il-62 and why was it necessary?

The tail prop was used as a safety precaution to prevent tilt on the ground when passengers or cargo were being loaded.

The tail prop is a safety measure to ensure that the aircraft doesn't tilt during loading and unloading on the ground.


Planes as early as the wright glider (1902) had a rudder, it appears from pictures that the 1900 and 1901 variants did not have rudders but its hard to tell from the photos.

Depending on your definition if you are talking about powered flight the Wright Flyer (1903) had 2 rudders much like its earlier glider predecessor.

In the lighter than air category, the Giffard Dirigible (1852) had a sail like rudder in the aft of the ship.

So that may take the cake if you have consider it a true rudder.

Side Note: Patented in 1930

the V-Tail design could be argued as the first design that did not (as far as I know)

employ a rudder.

The earlier Beechcraft Bonanza's are the most common plane of that design in commercial production.

There is quite a bit of debate as to the safety of ruddervators and the general theme seems to be that they are not perfect and do require some care to fly properly.

Rudder itself was used before the Wright.

It was just the idea of a rudder on a boat.

Otto Lilienthal flew a glider which had a tail with a modern look in 1894: Source

Actually the whole airplane has a modern look, like the cambered wing, Lilienthal was an aerodynamicist, he invented the polar curve .

Note: The rudder is not meant to control the aircraft direction

--this is done by rolling the wing,-- but to counteract the adverse yaw which develops when the wing is rolled (more drag on the upper half of the wing).

This effect can be obtained even with a fixed rudder (the turn will not be coordinated , but this tends to prevent a spiral dive).

Adverse yaw in a roll ( source , more in this answer )

So the size of the rudder is proportional to this force, which is smaller on small wings.

1785 ,when Jean-Pierre Blanchard crossed the English Channel in a balloon equipped with flapping wings for propulsion and a birdlike tail for steering according to pages 26-27 of L. Winter and G. Denger's "Minute Epics of Flight," published 1933.

We don't have photos, but we do have a woodcut .

The Wright Flyer had two rudders.

That flew in 1903.

Some of the wright bros. earlier gliders also had rudders ...

To test the technology and to determine the optimum size.

The 1785 balloon answer is interesting.

However, we might note that flapping wings would be extremely ineffective at propelling a balloon, and a rudder will have no significant effect on a free (unpropelled) balloon.

With that in mind, we might conclude that George Cayley was the first to suggest the use of a rudder in a practical way on an aircraft.

In 1799 George Cayley inscribed a coin with a picture of a design for a glider that appears to include a movable rudder.

By 1804 he had built a flying model glider that included a cruciform tail that could be adjusted on the ground both in the pitch and yaw dimensions.

By 1848 he had created an illustration of a full-scale glider that included a similar tail that could be adjusted in flight.

He tested a full-scale glider built along these lines in 1849, and a larger similar glider in 1853.

Here is one link that covers Cayley's work: http://www.flyingmachines.org/cayl.html

More recently, the Wright brothers first used a moveable rudder on their 1902 glider, and also used one on their famous 1903 airplane, generally recognized as the first airplane capable of sustained, controlled flight.

Having said all that, I wouldn't be surprised if someone located an earlier example of a rudder in a drawing or even an operational (small) model airplane or glider.

It is a fairly intuitive concept, deriving directly from naval technology--

in fact, the naval precedents might well have tended to lead early inventors to overestimate the advantages and results of having a movable rudder on an airplane.

Question: I have seen pictures of World War I-era airplanes that have rudders much smaller than today. When did the first rudder come out?

When was the first rudder on an aircraft used?

The first rudder appears to have been used in 1785 when Jean-Pierre Blanchard crossed the Channel in a ballon. On a plane, the earliest rudder was used on the Wright glider in 1902.

The Wright aircraft seem to be the earliest planes with a rudder. However, other earlier aircraft, including a dirigible and a balloon, also had rudder-like components.

Other earlier aircraft, including a dirigible and a balloon, had rudder-like components.


The remarks field, also called ITEM 18 field on ICAO flightplans can take a lot of information that you as the pilot deem necessary for controllers or authorities to know about your IFR flight.

The list of possible items in an ICAO flightplan ITEM 18 field is available over at the Skybrary , but here are a few examples that are commonly used: (c)

“TYP/” followed by type(s) of aircraft, proceeded if necessary by number(s) of aircraft, if “ZZZZ” is inserted in Item 9 Example: TYP/2 DE HAVILLAND HERON.

Up to 60 characters may be used.

(e)

“ALTN/” followed by the name of alternate aerodrome(s) or bearing and distance to navaid/navigation point closest to alternate point, if “ZZZZ” is inserted in Item 16.

Up to 100 characters may be used.

Example: ALTN/MEDIUM AIRPORT (k) “OPR/” followed by name of the operator, if not obvious from the aircraft identification in Item 7.

Example:

OPR/BIG COMPANY (o)

“RMK/” followed by any other, plain language, remarks when required by the appropriate ATS authority or deemed necessary.

There is no limit in number of characters to be used.

Example:RMK/TRAINING ILS APPROACH

AT SMALL AIRPORT RMK/STUDENT SOLO FLIGHT

No SID/STAR if flying a small airplane and can't make the required climb gradients.

Put anything that you believe would be relevant for the controllers to know, but not recorded in other fields.

For example, you are filing from XYZ to XYZ to shoot practice approaches.

You can put that in the remarks, noting airports where you want to practice.

This will help ATC handle your flight.

Around the Great Lakes it is common to put "NO OVERWATER" if you don't want to be routed over the lakes.

In helicopters, IFR flights can often terminate in S-VFR.

In this example, one might add "Request S-VFR from HELOG to Downtown"

First, ATC does see the remarks section of your flight plan.

You should use it for anything that you, as the pilot, deem relevant to your flight.

As a 34-year retired Chicago Center controller and lifelong flight instructor, I have taught students to use this on every flight.

NO SIDS/STARS;

NO

OVER WATER;

VFR GPS; NEW INSTRUMENT PILOT, etc.

In the controller world, a new instrument pilot is held to the same standard as a veteran airline pilot because we have no way of knowing the difference - unless you tell us.

Controllers are always trying to be efficient by turning aircraft onto final as close to the "approach gate" as possible.

This works great for seasoned IFR pilots but for new guys - not so much.

The localizer is flight checked to 18 NM.

A longer final for a new IFR pilot offers an opportunity for a more stable approach.

Why not put "REQUEST EXTENDED FINAL APPROACH" in the remarks section?

Just a thought.

Question: When filing an IFR flight plan, what information might go in the "Remarks" section?

What information might go in the remarks section of an IFR flight plan?

The pilot can put any information not included in other fields in the Remarks section. For example, you can state you do not want to be routed over water.

The remarks field can be used for any information about the flight that the pilot thinks may be relevant for the controllers or authorities. Specific examples include no SID/STAR and "no overwater".


South African Airways flights to 'less developed' locations in Africa often carry a mechanic and some spares on board.

If there are no suitable repair facilities, supplies or maintenance personnel available at the destination, then their own guy can fix any minor mechanical issues.

If there's a major problem then they would have to fly in additional repair supplies and staff (and fly out the stranded passengers).

I found this out on a flight from Johannesberg to Lilongwe (Malawi).

A seat was broken in the passenger cabin and SAA's on-board mechanic was able to fix it after a short delay.

The captain explained briefly why he was on board.

I assume that other airlines or operators who operate in undeveloped areas would do the same.

It's a lot cheaper to carry a mechanic and a few spares than it is to have an aircraft, crew and passengers stranded.

If anything on the MEL is broken then an airliner isn't airworthy so even a 'minor' issue can ground it.

I guess that the military might do the same for similar reasons, but I have no idea at all about that.

All of the 747-100/200 freighters I flew in the 1990s had FAKs (Fly Away Kits) aboard.

I just checked a couple of the weight & balance data sets I still have from having done weight & balance work for one of them up until 2013, and the weights were 1967 and 1939 lbs.

If the aircraft was a nose loader, the FAK was usually along the side of the in the vicinity of the retractable ladder used to get from the main deck to the upper deck.

If the aircraft was not a nose loader, the FAK was always up against the main deck forward bulkhead.

The FAKs were constructed of heavy duty plywood and opened from the top.

One of the airlines had two BOW configurations for each aircraft, one with its FAK, one without, to expedite weight and balance calculations with or without its FAK.

I've heard what you're describing called a "Fly Away Kit" or FAK.

After some brief googling, it seems the exact contents vary depending on the aircraft, operator, and the manufacturer of the FAK, but most seem to contain tools, spare tires, and other items for simple repairs.

Smaller kits are designed to fit behind a panel in the main cabin, while some larger ones are designed to fit in a Unit Load Device in the cargo hold.

I found a brief description here .

A fly away kit is a bunch of small spare parts and some tools and fluids to get the plane out of a place you don't have any support for the airplane.

We have one on all of our 727's because we operate into remote places that would take forever and a day to get a simple part to us that is a show stopper for the flight, it allows us to swap the part and fly away.

Things like spare landing light bulbs, radar altimeters, instruments, gyros, gauges and things like that are generally what I have seen and used from in there.

In addition we usually have a spare tire and sometimes a brake assembly somewhere in the belly.

Example of kit from airliners.net :

Yes.

If a US-registered aircraft is to be operated at night, it must carry: §91.205

One spare set of fuses, or three spare fuses of each kind required, that are accessible to the pilot in flight.

Now, as far as other types of spares go - no clue!

But some spares must be carried if certain requirements are met - eg, your airplane has fuses accessible from the cockpit.

In the event of an electrical problem, the flight crew can replace the fuse as required.

When I flew C-130 transporters in the RAF, we always carried a FAK and a 'Ground Engineer', but then the extra weight was of little consequence compared to the delay of the mission in some remote location.

I now fly Business Jets, where there is significantly less room, less available (spare) payload weight, and certainly no-one qualified to make the repairs on board, so the only thing carried is a small set of wheel chocks, a couple of cans of oil and clamps for the trust-reversers.

Normally planes don't have major spare parts.

Instead of parts they have redundancy in almost every flight system, which under certain circumstances an experienced pilot can take advantage of in order to keep operating the plane safely.

Have in mind that the weight issue in a plane is very important.

That's why a popular phrase between pilots says: Every takeoff is optional, but landing is mandatory

Question: I was curious to know, are there (or were there) any aircraft that regularly carry spare parts to be used for replacement or repairing the aircraft itself? If so, what are those spare parts?  I'm not talking about built-in redundant systems like a second radio, but rather actual physical spare parts. For example, a car carries a spare tyre.

Do any aircraft carry spare parts for making repairs?

Planes do not normally carry major spare parts. However, South African airlines carries spares to "less developed" locations in Africa. RAF planes and transporters in the 1990s carried a "Fly Away Kit". Nowadats there is little room for anything major.

Major spare parts cannot usually be carried on board due to space and weight requirements. However, planes do tend to have what is known as a "fly away kit". There are some instances in which there will also be an engineer or mechanic on board.

Planes do not usually have major spare parts but they do tend to have what is known as a "fly away kit". There are some instances in which there will also be an engineer or mechanic on board.

Major spare parts cannot be carried on board due to space and weight requirements.


This really depends on the type of aircraft and the seating position of the pilot.

In smaller aircraft, you will have a good view of the area around you, depending on the canopy.

In larger aircraft, the instrument panel and cockpit design can restrict your outside view a bit more.

Below

you will find two pictures taken from the cockpit of a Super Dimona HK36, used for VFR general aviation flights.

Both are approximately at eye level.

(Source:

Own Work - SentryRaven) (Source:

Own Work - SentryRaven)

In a document A319/A320/A321 Flight Deck and Systems Briefing for Pilots (can be found in many places on the net, e.g. on slideshare as presentation ), or page 16 Airbus shows following diagram of visibility from cockpit: 17 or 20 degrees below horizon is not that bad.

It is probably a little less than you see from a typical car , but not by much (of course since the pilots are sitting much higher, the nearest point on pavement is correspondingly further away).

Note, that whether the above is actually true depends on how the pilot adjusts their seat.

The recommended height for eyes is marked on the post between the forward windows.

In general, the pilots are required to have good visibility to execute any maneuvers during normal operation of the aircraft.

According to Federal Aviation Regulations Part 225, Section 773- Pilot Compartment View , during non-precipitation conditions, Each pilot compartment must be arranged to give the pilots a sufficiently extensive, clear, and undistorted view, to enable them to safely perform any maneuvers within the operating limitations of the airplane, including taxiing takeoff, approach, and landing The FAA advisory Circular 25.773-1

Pilot Compartment View design considerations gives certain guidelines for ensuring pilot visibility.

Pilot compartment view from FAA AC 25.773-1 Pilot Compartment View design considerations

The figure shows a pilot compartment view for optimum collision avoidancewhen seated in the left (port) seat.

For the starboard side, all left/right dimensions are reversed.

Usually, the aircrafts offer better visibility compared to the guidelines.

For example, the A330's visibility (from Flight deck and system's briefing ) is given here.

Image from A 330 Flight deck and system's briefing

The actual visibility of the pilots will vary according to the seat position For example, the following figure shows the variation in pilot visibility in Boeing 727 when seat position is adjusted.

Image from Airplane Design-

Layout Design of Cockpit, Fuselage, Wing and Empennage by Jan Roskam

Of course, the pilots can see things which is normally not visible though the windows through cameras mounted on the outside, like on top of vertical tail in A380.

This might be a stupid answer, but you can see a lot of take-off, landing videos from cockpit in YouTube.

Here's one:

I'll illustrate some aspects which I think even the best flight simulation today cannot compensate: Peripheral vision Telling distances and relative positions is much easier.

For example, you can tell a certain building is 1000 feet away.

When you are landing, you can take a quick glance to either side of the runway and judge whether it is time to flare.

Sitting in the cockpit of a 747 feels rather like standing on top of a 3-story building.

The best part is, this building moves!

It's truly amazing.

Detailed view

I know this sounds obvious, but I have to put it as number two.

Even when you are on final, you can see the little cars with people moving around the ramp and terminal.

The cockpit glass is just like the windshield in your car; if you can see something directly, you will see it in the cockpit.

You will also see the small cracks in the windshield, especially when sunlight is directly shinning at it.

This is a natural property of the material used.

If you're flying a single-engine propeller plane, your view will be slightly obstructed by the spinning propeller.

Other planes Spotting other planes in a real cockpit is a bit tricky.

If the plane is below you, and you're flying over residential areas with lot of houses, it can be hard to spot.

As stated in the comments, the view you get in a PC based flight simulator is not representative of the real thing.

To get a decent approximation of what you actually see from an airliner cockpit you'd need at least 6 screens in 2 rows of 3 screens each.

This of course requires quite a bit of hardware to accomplish :(

Using the virtual cockpit feature of some flight simulator software, and cranking up your viewpoint a bit from the default settings, you can get a much more authentic experience already

but it's still limited by the tiny viewport offered by even a larger widescreen computer monitor (let alone a 17" 4:3 display which is what many of them are programmed for as it's the smallest common denominator).

Of course that virtual cockpit has its own drawbacks in that the instruments are often a bit blurry and buttons and knobs less responsive than in the 2D view (let alone reality).

It's a set of compromises we have to live with as PC flyers, dictated by the limitations of our hardware and budgets.

Question: As I have never flown inside a cockpit, but only played with simulators I find that the dashboard takes most of the field of view(or am I wrong?).  So what actually can pilots see given good weather conditions, especially during critical parts of a flight, like take-offs and landings ?   I'm generally interested in big airliners.   P.S. I am not asking if they could takeoff/land without visual contact.

What do pilots actually see through the windows?

What a pilot sees in through cockpit windows depends on the type of plane. In general pilots see what is normally visible plus the cracks in the windscreen, Of course, in commercial airliners, pilots can also see what is not normally visible through the mounted cameras. In smaller aircraft, you have a good view of the area around, depending on the canopy.

What the pilot can see is dependent on the type of aircraft and the pilot's seating position. In smaller aircraft, pilots tend to have a good view of the surrounding area. External cameras also allow pilots to see more. Difficulties include spotting other planes. In propellor planes, the pilot's view may also be obstructed by the propellor.

In smaller aircraft, pilots tend to have a good view of the surrounding area. External cameras also allow pilots to see more. Pilots may also see the small cracks present in the windshield.

It can be difficult to spot other planes. In propellor planes, the pilot's view may be obstructed by the propellor.


Because air travel is the best option in those places.

The shortest commercial route in the world is between Westray and Papa Westray in the Orkney Islands, a distance of 1.7 miles.

If you see the list of short routes , almost all of them are between islands.

That instantly rules out buses and the like unless a bridge is built, which in most cases is not commercially viable.

One can use a boat or ferry, but in most cases, the sea may not be deep enough or calm enough.

Most very short distance flights are flown between Islands.

If you have a look at the list of such flight you can see they are places which are not or highly unlikely to be connected by a bridge which may be uneconomical.

Also the flights that are used on these routes are not the average airliners.

They are aircrafts like De Havilland Twin Otter and Cessna Caravan propeller planes which are very efficient at relatively slow speeds and low altitudes.

The ATR42 & ATR72 are examples of large propeller planes in service.

They are meant for short trips with the 72 having a max range of 1500km.

They are also able to land in very short distances.

Ideal for these island destinations

Fjords are also a reason these short routes exist, e.g. the trip from KKN to VDS takes less than 10 minutes, vs. driving 165 km (2h 16min according to Google: https://goo.gl/ev5dya )

One point not yet mentioned is that most of these short flights are not just between islands, but in archipelagoes.

So an aircraft may be dearer to run than a ferry, but the aircraft can do six or seven journeys a day (e.g. Westray to Papa Westray and back, Westray to Mainland, Mainland to Hoy...) and save the costs of three or four ferries.

One other rational for unusually short overland flights is that the short hop is a layover to connect two small airports to a larger one.

A few years ago it was possible to fly between Johnstown PA (JST) and Altoona PA (AOO);

which are ~30 miles/60 minutes apart by road.

It wasn't because the airline expected significant amount of traffic between the two towns.

The main route was between Johnstown and Washington-Dulles Airport (IAD) which was flown 3(?)

times a day; one of those flights stopped in Altoona with the primary intent of offering a connection from it to DC.

This stop was cancelled in 2014, and only the direct flight is still offered.

Both airports are very small rural locations and commercial traffic is partially funded with Federal Subsidies , so simple economics aren't the only consideration in the route planning.

aviation.stackexchange.com/users/1396/Dan Is Fiddling By Firelight

Question: I was impressed to read  here  that some passenger airline routes are even below 60 km in length.   Even assuming that the passengers are already in the airport past the security check, probably a good bus could depart from the same gate and arrive to the destination gate in a very comparable time, as the plane still needs to taxi before and after the flight.   Why these short haul flights are reasonable?

What is the rationale behind very short distance flights?

Most very short flights are in places where flying is the best option, for example between islands or across fjords. The other rational is a layover to connect between small airporats and a larger one.

Very short-distance flights take place when they are the most practical travel option. Most very short-distance flights are between islands or fjords. Another reason for very short-distance flights may be if a stopover is involved.


The C-124 had a opening in the rear, through which cargo (or paratroopers) could be dropped.

From globalsecurity.org : The C-124 was also used for airdrops. ...

In the back of the plane, the underneath of the airplane had elevator doors that opened up and the crew could drop cargo out, or paratroopers could jump out.

Here is an image of the elevator doors in open position The rear elevator opening of the Douglas C-124 Globemaster II where an elevator platform could be lowered or raised for bulk cargo operations (often the platform was removed so an interior hoist could directly move cargo) —

photo by Joseph May; image from travelforaircraft.wordpress.com Here is a C-124 using that door for an airdrop, presumably in Antarctica (I've put the image as I came across; I'm pretty sure that it's rotated) Image from antarctica.recollect.co.nz

The crew must've used the rear door rather than the front one for jettisoning the nuclear weapon.

The text of the official report reads:

The C-124 aircraft was en route from Dover AFB, Delaware, when a loss of power from the number one and number two engines was experienced.

Maximum power was applied to the remaining engines, but level flight could not be maintained.

At this point, the decision was made to jettison cargo in the interest of safety of the crew and aircraft.

Three weapons and one nuclear capsule were aboard the aircraft, and nuclear components had not been installed in the weapons.

The first weapon was jettisoned at 4,500 feet altitude.

The second weapon was jettisoned at approximately 2,500 feet altitude.

With the difficulties the crew was experiencing in keeping the aircraft level, it would only be logical that the rear doors were used, not the front.

As a loadmaster on c124s in the 50s

the the cargo elevator platform can be jettisoned and cargo can be jettisoned out the opening.

The flight manual tells you the clamshell front loading door will never be operated in flight.

It has 4 safety large pins installed all the time unless it is in use to load or offload on the ground.

I know as I have over 5000 flight hours as a loadmaster on c124s.

If you have oversized items, they go down with you and the aircraft.

We did carry parachutes if we needed them.

The flight Manuel tells you the clamshell door will never be operated inflight

it has 4 safety large pins installed all the time unless it is in use to load or offload on the ground.

I know as I have over 5000 flight hours as a LOADMASTER on c124s.

The front doors on the C-124 could NEVER be opened in flight.

Doing so would cause catastrophic failure.

The door hinges could not take the wind and would certainly take out the two inboard props, and probably the aircraft vertical and/or horizontal stabilizers.

If some miracle occurred and the doors flew off without hitting anything else, the drag of that huge open maw would be so great that the only way to fly would be at maximum power, and in a very steep dive.

In addition, the skin of this airplane is riveted for outside pressure, not inside pressure.

The wind pressure of that 200+ mph wind inside the aircraft would blow out the skin, leaving, at best, an aircraft skeleton.

And since the aircraft was semi-monocoque construction, relying on the aircraft skin for a significant part of the integrity of the fuselage, the loss of the skin would certainly cause the fuselage to break in two.

Paratroops exited via two troop doors on the side of the aircraft toward the rear.

There were also two troop doors above these, for troop drops using the upper troop floor platforms.

However, I have never dropped airborne from the second level, and don't think that it was ever done except, perhaps, in tests or shows.

I was with the last Troop Carrier Squadron in MATS/MAC, the 63rd Troop Carrier Wing, which folded Hunter AFB, Savannah, GA, and its use of the C-124, in 1967.

The elevator platform is approximately 8x12' (olllllld memory).

The elevator platform was part of and level with the cargo compartment floor, and is held in place by large locking bolts/pistons.

The platform is moved up-down, for-aft with two electric winches, which can move the platform down to the ground, and once inside the cargo compartment, to the front and rear of that compartment.

The elevator could not be used when the upper troop deck floors were in place.

We carried the upper deck floors on most missions except when the mission order called for their removal.

However, when Viet Nam got hot and heavy, I seem to remember not carrying them any more from about 1966 until I left the 61s ATW when they folded their C-124 mission in late 1969.

Not carrying the decks yielded a couple of thousand pounds more useful load, and a little bit more room for cargo.

We jettisoned the cargo elevator (with pallets) in flight over the North Atlantic.

On another flight while coming in to Sondestrom AFB in Greenland, the upper hinge on the right front clamshell door (viewed from inside while airborne) sheared in flight.

We already had 1 engine shut down due to malfunction.

I remember loosing altitude at a controlled rate wondering if we would make the coast, and if so, would the door completely fail on impact of landing and foul the main landing gear.

We made it to Sondestrom and landed without further incident, but I also remember the pilot stopping on the runway short of smoking the tires as the fire-equipment raced up and surrounded us.

We deplaned on the runway.

If you are desperate enough, even front cargo doors can be opened in flight.

C-124 Globemaster II being unloaded (picture source )

Note that the hinge line is almost in flight direction.

When flying slowly, the aerodynamic loads are small enough to crack the doors open.

Actually, their shape will result in a suction force over most of their length, so the hard part is closing them again.

Once the doors are slightly open, the load can be pushed out without much change in the center of gravity since the forward edge of the cargo floor is only slightly forward of the wing's leading edge.

Question: I was reading about a C-124 that was carrying three nuclear weapons over the Atlantic, and developed engine trouble. The article said that two of the weapons were jettisoned into the ocean for safety reasons. I was wondering how you can drop something from a C-124 in flight? Unless they were small enough to push out the back side doors. This happened on July 28, 1957.

How can cargo be jettisoned from a C-124 in flight?

The C-124 has a rear opening for dropping cargo or paratroopers. In a desperate situation, even the front cargo doors can be opened during flight.

There was an opening at the back of the plane. And if the situation is extreme enough, even the front cargo doors could be opened during flight.

If the situation is extreme enough, even the front cargo doors could be opened during flight.


Airports already have several ways to move aircraft along taxiways Aircraft engines (least economical but always available) Tugs (often used for pushback from terminals)

Aircraft wheel-motors (some makers are at least planning for electric taxi) A system of fixed chains along a complex network of intersecting taxiways would be expensive to install and maintain and might be unreliable (e.g. icing up in cold weather).

See also Does it make sense towing airplanes to the head of airstrip by external means?

An airport has taxiways that cross other taxiways and runways, so any chain system would require breaks in the chains at these points.

Airplanes would need some sort of motive power to cross these breaks, it's impractical and slow for an airplane to spin up its engines for 20 seconds to cross a break in the chain.

A chain system would also be very expensive to install and run, probably more expensive than the fuel it takes to taxi the airplanes.

They don't do it for roughly the same reasons that they don't install such systems in roads.

Expensive modifications would be required to every aircraft of a vast array of aircraft types.

This alone would probably mean that you'd never recover the costs over the entire expected life of the system.

And getting modifications approved by the relevant regulatory agencies for airworthy aircraft designs is even more of a pain than getting them approved for road-worthy car designs.

The systems themselves would be quite expensive for initial install, especially if they were designed to operate in all weather conditions in which airports can currently operate.

Being able to drive where you want is much more flexible (which is somewhat less of a concern at an airport than on roads, but still a concern.)

Stopping or turning suddenly to avoid a collision (like when you're cleared to taxi across a runway and suddenly realize that there's a Learjet taking off on it ) might not be possible or would at least be slower.

In short, there are already cheaper alternatives that don't suffer these drawbacks, such as tugs (manual or automated,) electric motors on the gear, and, of course, aircraft engines, as mentioned in RedGrittyBrick's answer .

One point has been missed in the other fine answers.

On an aircraft carrier, the nose gear of each aircraft has a pull bar installed that links with the catapult sled.

This pull bar is manually engaged by a deck crew member for each aircraft that is to launch.

In order to do this at an airport, there would need to be a ground handler stationed at each runway turn-off point to engage the pull bar to get the aircraft moving.

I pity the poor souls who would have to stand next to a runway at KBOS or KJFK in the wonderful weather they are expecting this weekend.

It's possible that this system could be automated, but that's another very expensive design element that has to be brought into play, tested, and receive CAA certification.

In addition to all the 'minor' drawbacks already discussed, there is one huge, basic problem with this idea.

What has to be moved is an airplane, weighing less than about 600 tonnes, designed to move, with a manageable rolling resistance.

A chain or cable system extensive enough to take its payload everywhere

it should go adds many tonnes of metal to move with a lot of friction, that will only grow as water and dirt enter the trench.

The whole thing will need enormous horsepower just to get moving even without an aircraft attached.

Compared to a tug, or even compared to an aircraft taxiing under its own power, this will simply need too much energy to be feasible.

The only place where this system can make money is in some streets in San Francisco.

Also, note that the modifications to fighter planes (Air Force vs Navy) are fairly significant, as the forces on the plane (and humans inside) are significant when using the arrestor (sp?)

cables on aircraft carriers.

And yes, reducing the force is possible, but reducing it so that all existing planes flying could use it may (mostly) eliminate its benefit.

Question: I am referring to the mechanism used in aircraft carriers, which help in catapulting fighter aircraft. What I had in mind is a milder version of the same concept. It would massively save cost, due to it being operated by electric power, save energy and time of the pilots, less exertion.  Would such a system be feasible?

Would a chain strip built in the airport taxiways, help airlines in saving money and time during taxi?

A chain system would be quite expensive to install and run. Moreover, it would require breaks where taxiways cross other taxiways or the runways. Stopping or turning suddenly to avoid a collision might not be possible or would be slower.

Several potential disadvantages are cited. Such a system would be very expensive. In addition, a chain system would need breaks in the chains where taxiways cross one another. Moreover, it would be much harder, or potentially impossible, to stop or turn in order to avoid a collision.

A chain system would need breaks in the chains where taxiways cross one another.

It would be much harder, or potentially impossible, to stop or turn in order to avoid a collision.


You can, but you have to live with the consequences.

There are several things that can happen: Depending on the vertical gusts ahead, you might not even get close to v$_{NE}$. There is another speed limit for gusty weather called v$_B$ , and exceeding this will run the risk of overstressing the wing structure.

Going above v$_B$ will overstress the wings in a gust of more than 50 ft/s, and more than 25 ft/s

when flying above v$_D$.

The exact values can be found in the flight envelope diagram of the flight manual.

On a calm day, you can fly v$_{NE}$ and even a little faster, but once you fly fast enough, flutter will become very likely.

Note that flutter needs some initial excitation , so you might fly well into the flutter speed range before flutter occurs.

When it does, control surfaces will be ripped from their fittings which will make the aircraft pitch up.

At that point the wings will break off.

The engine on a C 172 is not powerful enough to sustain level flight at v$_{NE}$. You need to dive the aircraft, which requires some altitude.

Maintaining the speed will mean that you dive into the ground, so you need to pull out of the dive in time.

On really fast aircraft the pitch trim will get more nose-heavy when the aircraft approaches the speed of sound.

You don't run that risk in a C 172, but faster aircraft found themselves locked into a dive which they could not end .

You can exceed the never exceed speed $V_{NE}$, but doing so will most likely result in damage to the structure.

From FAA handbook of pilot knowledge : $V_{NE}$ —the speed which should never be exceeded.

If flight is attempted above this speed, structural damage or structural failure may result.

Because above that airspeed, the airframe is increasingly likely to fail.

Failure would likely start with control surfaces like the ailerons, elevator and flaps, then the wings and tail are likely to separate, resulting in total catastrophic failure.

Think of $V_{NE}$ as the speed at or beyond which the structural integrity of the airframe is not guaranteed.

In other words, parts of the airframe - which is critical for controlled flight cannot be guaranteed to perform as designed.

There are both aerodynamic and structural reasons for Vne.

Aircraft controllability is impacted (for specific impacts on a specific make and model, consult with the manufacturer and perhaps they will share their findings from testing) and you may encounter difficulties with control authority (your ability to move control surfaces), airflow (e.g. the Clark-Y airfoil is designed for its lifting capability far more than it is designed for speed), and you may exceed the structural limits of aircraft components (control surfaces, wing spars, windshield, landing gear.)

Operating above Vne now places you in the role of de-facto test pilot and any damage you cause to your aircraft may manifest itself that same flight or many hours later when the results of stresses you induced on the airframe or cables, pulleys etc.

cause a failure of the aircraft structure.

The answer depends on how much you exceed V_ne.

I do not have the information for this particular aircraft in front of me, so I can not say what will happen at a specific airspeed.

Cessna spent a lot of money and time on engineering and flight testing to come up with the maximum airspeed (V_ne).

There is a safety factor built in to this calculated and tested speed.

One situation is flying level at a high altitude, then go in to a steep dive.

This may cause an overspeed condition.

One of the first problems as a result of overspeed, will start out as a vibration of control surfaces and controls.

The chance for loss of control by the pilot due to mechanical failure or metal fatigue will increase exponentially, as does the airspeed.

The C172 has airfoil designs meant for low speed.

Depending on the exact plane and loading this could differ slightly, but the stall speed is 49 KIAS.

With its straight, high lift wing structure, the airfoil may actually completely loose its lift at a very high airspeed.

As the airspeed increases, farther above the V_ne, the craft will basically start to tear apart and disintegrate.

As stated in another response the stock engine in a C172 isn't powerful enough to sustain Vne in horizontal flight.

Establishment of the various speeds is part of the aircraft certification process and usually includes a safety margin of 10 to 15 percent and there are many factors that go into determining these numbers.

For example, I have a Beachcraft Baron and one of the important speeds is Vr or V Rotate.

It's not that the aircraft cannot take off at a slower speed

it's just that if you have a critical engine failure at takeoff power and a slower speed you don't have enough control authority to compensate.

There are many factors that go into determining these numbers and structural integrity

is just one of them.

To add to previous answers, Vne is usually set at near ideal conditions, therefore the 10% - 15% mentioned above really becomes nothing if there are air pockets or other phenomena usually not meaningful, let alone minor fatigue or skin imperfections, hence, as the name implies, never exceed this speed with standard issue airplanes.

Question: The airspeed indicator has a red marking that means: "never exceed this speed" ($V_{NE}$, around 160 KIAS). Why can't you exceed that speed?

What happens if you exceed the maximum speed on a C172?

Although the never exceed speed can be exceeded, it would result in damage to the structure. It would also lead to the aircraft becoming more difficult to control.

Exceeding this speed is likely to cause structural damage or even failure of the airframe and may impact the ability to control the aircraft.

Exceeding this speed is likely to cause structural damage or even failure of the airframe.

Exceeding this speed may impact the ability to control the aircraft.


Ex-Royal Air Force helicopter force here, spent a lot of time around Chinooks.

I think the main answer is "because I can", but I can think of a legitimate combat use.

You are heavy, and forced to land downwind into a narrow strip because there is a hazard on the upwind side of the landing zone.

There is not enough room to turn around.

You could hover taxi backwards like this to pick up some inflow into the rotors from the relative airflow (and therefore increased lift), then climb away backwards until you do have enough room to transition into normal forward flight, more or less as shown in the video.

This is where team work kicks in - you've really got to trust your load master who is telling you exactly where you are.

Never seen it done though.

What you are seeing is whats called a Pinnacle Landing or Pinnacle Maneuver .

Why its practiced is much cleared from the below image.

The Chinook has a large base that may prevent it from safely landing in circumstance that require an evacuation from a small raised area.

It looks like it's done to showcase the impressive level of skill & control that the pilot is able to achieve w/ this aircraft.

Sort of like the Ken Block Gymkhana video series, where he's showing off amazing car control, but you would never want to drive like that except in a drifting contest.

Stretching the definition of 'practical', if you needed to tow something a short way & you had no pickup truck available, but somehow you did have a Chinook helicopter w/

a world-class pilot....

this would kind of be an option Source: I just enjoyed the mental image of someone using a Chinook as a pickup truck

When our CH- 46 (PHROG) pilots are moving the aircraft on the runway they were directed by ground crew like myself, there are plenty of times we would taxi them forward and backward

so I don't believe it would be "just because" or "showing off".

It's part of every pilots training as is the rear wheel landing or "pinnacle landing" which is used to land on rooftops and mountain tops hence pinnacle.

My guess is that if you need to get into and out of a 'hot' strip this approach would minimise the time (and position in the sky) that you would be exposed to enemy fire.

Just the sort of flying that might be needed on special ops.

Question: At 4:30 in this YouTube video, a Chinook traverses the runway on its rear wheels. The text on the video lists "Emergency landing and take-off". Is there any reason for the pilot to do this other than "because I can and it's an airshow"?     The pilot then proceeds to back down the runway on the rear wheels, a maneuver that I can only imagine is showing off, but again, is there a legitimate flying need to do this?

What would the reason be for this helicopter maneuver?

This maneuver is called a Pinnacle Landing. It could be used tominimise the time you would be exposed to enemy fire. It also showcases the impressive level of skill and control the pilot can achieve with this aircraft.

While some believe that this maneuver is being performed to showcase the pilot's skills, others state that it would be performed if an evacuation was required from a small raised area. Another possible reason for performing such a maneuver would be to reduce exposure to enemy fire in a hostile situation

This maneuver, known as a pinnacle maneuver, would be performed if an evacuation was required from a small raised area.

The maneuver is being performed to showcase the pilot's skills.

This maneuver would reduce exposure to enemy fire in a hostile situation.


I will answer your question with what we can see in Brazilian Airspace and its rules.

In Brazil, there are some airports - non towered, operated by radio stations - which give information such as wind direction/intensity and temperature and QNH.

Based on this information, the pilot decides on which runway they will land or take off, and relays this message to the radio operator.

The operator will only relay these pieces of information to pilots monitoring the radio frequency.

Those airports are not controlled, then, if there is any strike, flying visually, no control will be effective.

For example, ARU/SBAU is a non towered airport, and TAM Airlines operates the A320F there.

The Canadian Arctic has B737 scheduled airline operations to many uncontrolled airports that have no control tower.

American Airlines operates an A319 seasonally from DFW to Gunnison (KGUC), which is an uncontrolled airport .

There are probably many other similar examples.

An airline flight arriving at an uncontrolled field operates just like any other aircraft: it will almost certainly be IFR and fly an instrument approach, or a visual approach if conditions allow it.

Radio calls, pattern etc.

should be the same as for any other aircraft arriving IFR at an uncontrolled airport.

The airline's OpSpec might have some specific procedures for uncontrolled airports, but otherwise it's just another aircraft.

Controllers going on strike is a totally different scenario; you might want to ask about that separately.

Any plane can land at any airport as long as the runway is long enough.

There is no regulation saying that a 737 cannot land at a non-controlled airport.

All of the commercial pilots that have had their training in the private sector have had to land at non controlled airports.

I say all, but I'm sure there are some exceptions.

Let's just say most.

It is no big deal.

Here at our local airport, KLBX, there is no tower and there are four large jets that come and go every single day, even when the weather is IFR.

There is so little realistic understanding of aircraft and air travel due to the continued misrepresentation by the media and movies.

There was the incident of the control tower guy falling asleep and the commercial flight had to land without the tower control.

It was all over the news as though it was a miracle that the plane didn't just crash all over the place.

As though a pilot cannot land a plane without the tower saying "Cleared to land 13R.

" That's all they do anyway.

The pilot is still responsible for looking and seeing if the runway is really clear and ready to take the plane.

In IFR conditions there is still what's called the minimums.

If you can't see the runway when you reach the minimums you are not allowed to land there.

Again, there is an exception, but it won't be available at non-controlled airports because of the cost.

I don't know about Brazil or Japan or any other country.

I fly in the US only, and most of it in Texas.

You'd be surprised how many non-towered airports there are where you even have to turn on the runway lights from your plane at night.

Usually any airport with enough traffic that it would attract a big commercial jet will merit a tower.

However, there are a few weird exceptions here and there and some of the other answers have described these.

I think you may be thinking that a tower would be necessary somehow or that flying a heavy into an airport without a tower would be dangerous, and that is not necessarily true.

Pilots can self-organize and land themselves just fine without a tower.

The tower is mostly there to speed things up and enable large volumes of aircraft to land as quickly as possible.

If an airfield is busy and there is no tower, then the aircraft will tend to spread themselves out more, approach from longer distances and do things more slowly.

With the tower there it speeds everything up.

If an airport is out in the middle of nowhere and does not get any traffic, then there is no need for a tower and it does not really matter whether the plane is big or small.

Question: Are there any airports with scheduled services where big jets (say 737 or A320) or wide bodies regularly operate without control tower?   Are there any rules (EASA FAA) for this?   If controllers go on strike can commercial air transport continue to operate?

Can commercial air traffic operate from uncontrolled airport, airspace?

Commercial aircraft can operate into and out of uncontrolled air fields. Air fields have towers when they have a large volume of traffic, it is nothing to do with the size of planes using the field. Pilots can organise take off and landing without the tower. The tower serves to organise traffic on busy airfields. Air Canada and American Airlines are examples of large airlines that fly in and out of uncontrolled airports.

There is no regulation stating that a 737 is not allowed to land at an uncontrolled airport. Aircraft can land safely without a tower, provided that there is a long enough runway. Pilots are able to organize amongst themselves and if an uncontrolled airfield is busy, they will take action to compensate.

There are many examples of airports without a control tower. If an airport is in a remote location and does not get a lot of traffic, there is no need for a tower. The purpose of the tower is to speed up the flow of traffic. If an airport does not have much traffic, there is no need for a tower. However, if an airport gets enough traffic to attract a large jet, it will usually also have a tower.

Aircraft can land safely without a tower, provided that there is a long enough runway. Pilots can organize amongst themselves and if an uncontrolled airfield is busy, they will take action to compensate.

If an airport gets enough traffic to attract a large jet, it will usually also have a tower.


Military transports are designed to be operated from unpaved runways- by extension, any of these converted to civilian use can operate from unpaved runways.

For example, the Antonov Airlines operates a number of Antonov An-124 'Ruslan' , which can and do operate from unpaved runways regularly.

The Volga-Dnepr group specifically states: Multi-leg landing gears equipped with 24 wheels allow to operate the aircraft on unpaved runways ...

The H-4 Hercules (Spruce Goose) should easily win this contest.

That plane was ridiculously huge and, in fact, couldn't use a runway,

rather it was a "flying boat" that took off from the the water.

So I'd say it's the one...

Granted, if you mean a grass or gravel strip aeroalias is probably correct.

The only other major planes that I know were designed to land on gravel were the early 737 and the 727 .

They both had special landing gear guards that keeps the front gear from kicking gravel into the engines and both

have specific instructions for preparing the landing gear for touch down on gravel.

Here's the guard, if you were curious, on a 737:

Source https://www.flickr.com/photos/capnmikesphotos/14891693505 , Author: Mike Pearson

It's not quite as big as the Antonov An-124, but honorable mention would have to go to the Lockheed LC-130 .

It's designed to resupply scientific and military operations in polar regions, and so it has a dual wheel-and-ski landing gear setup that allows it to take off from and land on snow and ice.

(Image source: Wikimedia Commons)

These oldies seem worth mentioning...

If you loosen your definition of "airplane" to " the longest class of flying machine and the largest airship by envelope volume " you could think of a Hindenburg-class airship that was in regular commercial service.

They landed in fields

They're more comparable in size to buildings or very large boats, rather than other airplanes Hindenburg in green compared to Blue: The Pentagon building, Pink: Queen Mary 2,

ocean liner

Yellow: USS Enterprise, supercarrier Dark blue:

Yamato, WWII Japanese warship

Grey:

Empire State Building

Red: Mont, a supertanker Compared to other airplanes (Hindenburg in orange): Or the Spruce Goose (* Not acutal Spruce) .

(Just noticed it mentioned in another answer, after posting this) Originally designated HK-1 for the first aircraft built by Hughes-Kaiser, the giant was re-designated H-4

when Henry Kaiser withdrew from the project in 1944.

Nevertheless, the press insisted on calling it the “Spruce Goose” despite the fact that the plane is made almost entirely of birch.

Apparently it is "the largest flying boat ever built and has the largest wingspan of any aircraft in history" at 320 ft 11 in (97.54 m).

Not strictly a "regularly used" airplane, but Hughes retained a full crew to maintain the mammoth plane in a climate-controlled hangar up until his death in 1976.

Going off on another direction if ice counts as "unpaved", a Boeing 757 was landed in Antarctica in November 2015, the first commercial airliner to do that.

Source is from the link above.

aviation.stackexchange.com/users/12220/SMS von der Tann

Another option might be the Soviet Ekranoplan: these are aircraft that use the ground effect to fly just off a surface of water.

For example we might have the Lun-class (73m): or the experimental Caspian Sea Monster (92m): Sadly neither of these are flying any longer.

(source:

Wikipedia Ground effect vehicle and Lun-class ekranoplan )

Question: Since we  don't need a control tower  for instrument landings I was wondering what else that is thought to be needed could be skipped. I know some small general aviation is done on grass runways and I was wondering what is the biggest airplane that does not need a paved runway? Examples of manufacturer-approved usage or regular (e.g. daily or weekly) usage are preferred.

What is the biggest airplane that does not need a paved runway?

Military transports are designed to be operated from unpaved runways- by extension, any of these converted to civilian use can operate from unpaved runways.  Examples of these would be Antonov An-124, Ekranoplan and the H-4 Hercules.

Military transport aircraft that can be adjusted for civilian use, like the Antonov An-124 'Ruslan' planes or the Soviet Ekranoplan that can take off a surface  of water, are considered the largest. However, if we broaden the definition of "airplane", then Hindenburg-class airships like the H-4 Hercules (Spruce Goose) would definitely come first.

If we broaden the definition of "airplane", then Hindenburg-class airships like the H-4 Hercules (Spruce Goose) would definitely come first.