The maximum landing weight (MLW) is the maximum

aircraft gross weight The aircraft gross weight (also known as the all-up weight and abbreviated AUW) is the total aircraft weight at ''any moment'' during the flight or ground operation. An aircraft's gross weight will decrease during a flight due to fuel and oil co ...

due to design or operational limitations at which an

aircraft An aircraft is a vehicle that is able to flight, fly by gaining support from the Atmosphere of Earth, air. It counters the force of gravity by using either Buoyancy, static lift or by using the Lift (force), dynamic lift of an airfoil, or in ...

is permitted to land. The MLW is set in order to ensure safe landings; if an aircraft weighs too heavy during touchdown, it may suffer structural damage or even break apart upon landing. Aircraft also have a

maximum take-off weight The maximum takeoff weight (MTOW) or maximum gross takeoff weight (MGTOW) or maximum takeoff mass (MTOM) of an aircraft is the maximum weight at which the pilot is allowed to attempt to take off, due to structural or other limits. The analogous ...

, which is almost always higher than the maximum landing weight, so that an aircraft can weigh less upon landing due to burning fuel during the flight. The operation landing weight may be limited to a weight lower than the maximum landing weight by the most restrictive of the following requirements: * Aircraft performance requirements for a given altitude and temperature: :*landing field length requirements, :*approach and landing climb requirements. * Noise requirements If the flight has been of unusually short duration, such as due to an emergency just after takeoff requiring a return to the airport, it may be necessary to dump fuel to reduce the landing weight. Some aircraft are unable to dump fuel, however. For example, on 3 February 2020,

Air Canada Air Canada is the flag carrier and the largest airline of Canada by the size and passengers carried. Air Canada maintains its headquarters in the borough of Saint-Laurent, Montreal, Quebec. The airline, founded in 1937, provides scheduled an ...

Flight 837, a

Boeing 767-300 The Boeing 767 is an American wide-body aircraft developed and manufactured by Boeing Commercial Airplanes. The aircraft was launched as the 7X7 program on July 14, 1978, the prototype first flew on September 26, 1981, and it was certified on ...

, suffered a rear tyre failure during take-off at Madrid–Barajas Airport on its way to Toronto, causing its left engine to catch fire. The pilots managed to extinguish it by shutting the engine down, but as 767-300s are not designed for fuel dumping, it had to stay in a single-engine holding pattern for over 4 hours to burn fuel and achieve its maximum landing weight, while an SAF fighter reported minimal damage to the landing gear. The plane landed safely and nobody was injured. Sometimes the emergency may be so pressing that the aircraft has no time to dump or burn fuel in order to achieve its maximum landing weight before touchdown; in that case, a risky overweight landing may be permitted. In other cases, the flight crew may fail to dump fuel when it still had the time to do so before landing, leading to fatal accidents such as

Aeroflot Flight 1492 Aeroflot Flight 1492 was a scheduled domestic passenger flight operated by Aeroflot from Moscow–Sheremetyevo to Murmansk, Russia. On 5 May 2019, the Sukhoi Superjet 100 aircraft operating the flight was climbing out when it was struck by lig ...

on 5 May 2019, where an apparently needlessly overweight landing turned into a crash that killed 41 of the 78 people on board. Where aircraft overweight landing is permitted, a structural inspection or evaluation of the touch-down loads before the next aircraft operation will be required in case damage has occurred.

References

Aircraft operations Aircraft weight measurements Aviation safety {{aviation-stub