There are two main types of submersible pumps. A well pump is hung or suspended in a water well on a pipe, sometimes to depths past 1000â. well pumps are powered by AC (alternating current) voltage but DC (direct current) voltage is used on smaller pumps for low flows of water up to a depth of 200 feet.
Since the systems make both airlines and travel agents more pro-ductive, CRS owners charge both of them for the use of their systems. Travel agents rent the equipment, while airlines pay a booking fee for each flight reservation. American Airlines introduced the first com-puter reservation system; United, TransWorld, Eastern, and Delta each followed with systems of their own. American and United, how-ever, dominate the CRS industry; in 1986, they accounted for 41 per-cent and 33 percent, respectively, of the flight segments booked through computer reservation systems. The influence of computer reservation systems on bookings can be
An e-ticket may include a reservation confirmation number. Some airlines allow passengers to choose a seat during online check-in. Checking in for a flight online can help passengers who may not have a lot of time before a flight takes off. Many airlines allow online check-in up to 24 hours in advance of the flight.