Airport Highlights 2008 0502 - Laserfiche WebLink

Home

Fuel dumping From Wikipedia, the free encyclopedia Fuel dumping from an aircraft is used to lighten the aircraft's weight in certain emergency situations. Fuel is typically jettisoned before a return to the airport shortly after takeoff, or before landing at an airport short of the intended destination. Although the landing gear has been designed to allow the aircraft to safely land at maximum takeoff weight, dumping fuel reduces the landing weight and therefore minimizes the risks associated with higher speed landings. Contents ^ 1 Aircraft fuel dump ^ 2 Dump-and-burn ^ 3 See also ^ 4 External links Aircraft fuel dump Aircraft have two major types of weight limits: the maximum structural takeoff weight and the maximum structural landing weight, with the maximum structural landing weight always being the lower of the two. This allows an aircraft on a normal, routine flight to take off at the higher weight, consume fuel en route, and arrive at a lower weight. (There are other variables involving takeoff and landing weights, but they are omitted from this discussion for the sake of simplicity.) It is the abnormal, non-routine flight where landing weight can be an issue. If a flight takes off at the maximum structural takeoff weight and then faces a situation where it must return to the departure airport (due to certain mechanical problems, or a passenger medical issue), there will not be time to consume the fuel meant for getting to the original destination, and the aircraft maybe over the maximum structural landing weight to land back at the departure point. As jets began flying with U.5. airlines in the late 1950s and early 1960s, the FAA rule in effect at the time mandated that if the difference between an aircraft's maximum structural takeoff weight and its maximum structural landing weight was greater than 105%, the aircraft had to have a fuel dump system installed. Accordingly, aircraft such as the Boeing 707 and 727 and the Douglas DC-8 had fuel dump systems. Any of those aircraft needing to return to a takeoff airport above the maximum structural landing weight would simply jettison an amount of fuel sufficient to reduce the aircraft's total weight to below that maximum structural landing weight limit, and then land. Fuel dumping point of an A340-311 During the 1960s, Boeing introduced the 737, and Douglas the DC-9, the original models of each being for shorter routes; the 105% figure was not an issue, thus they had no fuel dump systems installed. During the 1960s and 1970s, both Boeing and Douglas "grew" their respective aircraft as far as operational capabilities were concerned via Pratt & Whitney's development of increasingly powerful variants of the JT8D engines that powered both aircraft series. Both aircraft were now capable of longer duration flights, with increased weight limits, and complying with the existing 105% rule became problematic due to the costs RAAF F-111 aircraft performing a fuel dump-and- burn procedure, where the fuel being dumped is ignited, intentionally, using the plane's afterburner '~