Torqued: 'Hangar Rash' Can Mask a Serious Problem

 - February 5, 2018, 3:01 AM

We’ve probably all used the term “hangar rash” at one time or another to describe so-called “minor incidents” of damage. Usually the term refers to damage from moving aircraft in the hangar, but it can also refer to other incidents on the ground that cause minor damage. I have used that term myself without giving it a second thought. Until now. But as I look at several ground incidents that have happened lately with some fixed based operators, I’m beginning to think that term may be part of the problem. Referring to these events as hangar rash tends to minimize an expensive and potentially safety-critical problem.

One of the incidents that got me thinking about these words looked like fairly minor damage on the outside of one particular corporate jet. But it had significant consequences because of the location of the damage through the pressure vessel. The repair required approved engineering data and an FAA 337 major repair form, which becomes part of the aircraft’s permanent maintenance records. It can have a significant impact on the resale value of the aircraft. So even though the damage looked “minor” and the aircraft could be made airworthy readily and relatively inexpensively, the location of the damage through the pressure vessel and subsequent patch could significantly lower the value of the airplane to potential buyers. A minor incident with not-so-minor consequences can hardly be considered an innocuous sounding “rash.”

In the past, I have raised concerns that seemingly minor damage to composite surfaces can mask more significant issues. This is a particular concern when mechanics who have not received the specialized training necessary to evaluate composite damage are involved in assessing surface damage. Once the exclusive province of airliners, composites are now used throughout aviation, from airliners to corporate jets to single-engine general aviation aircraft. However, the specialized training of mechanics to evaluate damage—particularly the significance of seemingly minor surface damage—has not kept pace. This is a particular issue for corporate and other general aviation aircraft owners and operators. So many mechanics working these aircraft have little to no training on composites. What looks like a slight scrape on the surface of a composite can hide significant structural damage underneath. My concern is that calling damage on a composite surface “hangar rash” could result in a significant structural problem being overlooked.

Underlying Safety Lapses

My other concern with the use of the term “hangar rash” is that it can mask the significance of the events that led to the damage. Oftentimes, people mistakenly equate the severity of damage with the carelessness or recklessness of the conduct that led to it. In other words, if an incident results in minor damage, the erroneous conclusion is that the events that caused it were minor, and little or no effort is put into examining what happened and why. But that can be a very dangerous conclusion. Every accident investigator has seen fatal accidents that were triggered by minor lapses; and minor incidents that were caused by incredibly reckless actions. The most obvious example is a drunk pilot. Not every drunk pilot will crash, although flying under the influence of drugs or alcohol is among the most reckless acts one can imagine by a pilot. In other words, the severity of the outcome is not necessarily a good basis for judging the degree of negligence that was involved in an incident or accident. 

In my opinion, every incident of ground damage should be investigated to determine the root cause, so that in the future, more serious outcomes can be prevented. And programs that can protect employees from FAA enforcement action and company discipline for careless conduct should be put in place. Such programs encourage ramp personnel, who frequently don’t report incidents for fear of losing their jobs, to report ground damage. 

When “hangar rash” happens, it’s usually the result of some breakdown in proper procedures, often—in my experience—rushing to get a job done. This is especially true of the number one reason—in my experience—for hangar rash: an aircraft towed without wing walkers. There are many reasons why airport personnel may decide to move an aircraft without wing walkers. Maybe they misjudge the distance they have to navigate the aircraft; or they are pressured to move the aircraft and no personnel are immediately available. 

Ground damage is certainly a major economic problem for aviation users generally, whether airliners, corporate operators, or weekend fliers. According to the Flight Safety Foundation, using data developed by the International Air Transport Association (IATA) a number of years ago, “ramp accidents cost major airlines worldwide at least US$10 billion a year…These accidents affect airport operations, result in personnel injuries, and damage aircraft, facilities and ground-support equipment.” A more recent interpretation of IATA data has put the worldwide cost to airliners at $12 billion. And this data covers only major airlines. The costs to smaller airliners and general aviation isn’t even included. 

It’s probably time to do away with the term “hangar rash” and treat all ground damage incidents as indicators of safety problems whose root causes need to be determined and addressed.


Being a veteran of many, many hangar rash incidences (there were times when these kept the FBO MX dept. in business), and especially concerning composite surfaces, I have to ask the question:
How many disasters have been attributed to composite structures failing due to this? Are there many pile-ups because of unknown "mini" bumps and bruises, not counting of course, poor preflight (the elevators really need to be there!)?

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