Pushback

In aviation, pushback is an airport procedure during which an aircraft is pushed backwards away from an airport gate by external power. Pushbacks are carried out by special, low-profile vehicles called pushback tractors or tugs.

Although many aircraft are capable of moving themselves backwards on the ground using reverse thrust (a procedure referred to as a powerback), the resulting jet blast or prop wash may cause damage to the terminal building or equipment. Engines close to the ground may also blow sand and debris forward and then suck it into the engine, causing damage to the engine. A pushback is therefore the preferred method to move the aircraft away from the gate.

Procedure

Pushbacks at busy aerodromes are usually subject to ground control clearance to facilitate ground movement on taxiways. Once clearance is obtained, the pilot will communicate with the pushback tractor driver (or a ground handler walking alongside the aircraft in some cases) to start the pushback. To communicate, a headset may be connected near the nose gear.

Boeing 777

The Boeing 777 is a family of long-range wide-body twin-engine jet airliners developed and manufactured by Boeing Commercial Airplanes. It is the world's largest twinjet and has a typical seating capacity for 314 to 451 passengers, with a range of 5,235 to 9,500 nautical miles (9,695 to 17,594 km). Commonly referred to as the "Triple Seven", its distinguishing features include the largest-diameter turbofan engines of any aircraft, six wheels on each main landing gear, fully circular fuselage cross-section, and a blade-shaped tail cone. Developed in consultation with eight major airlines, the 777 was designed to replace older wide-body airliners and bridge the capacity difference between Boeing's 767 and 747. As Boeing's first fly-by-wire airliner, it has computer-mediated controls. It is also the first commercial aircraft to be designed entirely with computer-aided design.

The 777 is produced in two fuselage lengths as of 2014. The original 777-200 variant entered commercial service in 1995, followed by the extended-range 777-200ER in 1997. The stretched 777-300, which is 33.25 ft (10.1 m) longer, followed in 1998. The longer-range 777-300ER and 777-200LR variants entered service in 2004 and 2006 respectively, while the 777F, a freighter version, debuted in February 2009; these variants all feature General Electric GE90 engines and extended raked wingtips. The earlier 777-200, -200ER and -300 versions are equipped with GE90, Pratt & Whitney PW4000, or Rolls-Royce Trent 800 engines. The 777-200LR is the world's longest-range airliner, able to fly more than halfway around the globe, and holds the record for the longest distance flown non-stop by a commercial aircraft.