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
42 seat turboprop regional airliner History Aerospatiale and Aeritalia (now Alenia) established Avions de Transport Regional as a Groupement d'IntaÂ©intÃ£ Ret economique Under french law to develop a family of regional. Airliners THE-atr 42 was the'consortium s first aircraft and was launched In october. 19812 seat turboprop regional airliner History Aerospatiale and Aeritalia (now Alenia) established Avions de Transport Regional as a Groupement d'IntaÂ©intÃ£ Ret economique Under french law to develop a family of regional. Airliners THE-atr 42 was the'consortium s first aircraft and was launched In october. 1981