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An air turnback is a situation where an aircraft returns to land at the departure aerodrome without having initially planned to do so.
The most common reason for air turnback is an emergency or abnormal situation during or shortly after take-off, the most common being engine failure. If the problem happens during acceleration, the crew might attempt to reject the take off depending on the speed and the nature of emergency. Sometimes a safer option is to get airborne and then make an approach and land. A probable complication in this case is that the aircraft's current weight may be greater than the certified maximum landing weight (MLW). If the crew opts for a turnback in this case, there are three options:
- Make an overweight landing. The pilot in command has the right to deviate from prescribed procedures as required in an emergency situation in the interest of safety, i.e. they may choose to land even though the aircraft is heavier than the MLW if they consider this to be the safest course of action. The landing will be more challenging and require longer runway, thus increasing the chance of a runway excursion. Also, a special post-landing inspection will have to be carried out.
- Burning the excess fuel, e.g. by entering a holding pattern. This is a safe option in many cases but if it is considered that by the time the weight is reduced below the MLW the aircraft will no longer be airworthy, or there is another urgent matter (e.g. a medical emergency) another course of action will be taken.
- Dump fuel. This option is not available for most aircraft types and even if it is, the respective system may not have been installed on the particular aircraft. Additional restrictions may also apply, e.g. a minimum level to perform the operation or the need to reach a dedicated fuel dumping area.
Air turnback may happen during all phases of the flight, e.g. climb, cruise or even when the aircraft has reached the vicinity of the destination aerodrome (but is unable to land due to weather conditions). Any significant problem with the aircraft during the climb phase is likely to result in a turnback because of the closeness of the departure aerodrome. During the cruise, if an engine fails (or annother emergency situation arises, e.g. loss of cabin pressure), the flight crew will evaluate the situation and decide on the further course of action. Depending on the circumstances (severity of the situation, available fuel, company policy, weather, etc.), the choice may be to continue to the planned destination, to divert to the planned alternate, to land at the nearest suitable aerodrome or to return to the point of departure.
Accidents and Incidents
- B752, en-route, Northern Ghana, 2009 (On 28 January 2009 the crew of a Boeing 757-200 continued takeoff from Accra Ghana despite becoming aware of an airspeed discrepancy during the take off roll. An attempt to resolve the problem failed and the consequences led to confusion as to what was happening which prompted them to declare a MAYDAY and return - successfully - to Accra. The left hand pitot probe was found to be blocked by an insect. The Investigation concluded that a low speed rejected takeoff would have been more appropriate than the continued take off in the circumstances which had prevailed.)
- SU95, Moscow Sheremetyevo Russia, 2019 (On 5 May 2019, a Sukhoi RRJ-95B making a manually-flown return to Moscow Sheremetyevo after a lightning strike caused a major electrical systems failure soon after departure made a mismanaged landing which featured a sequence of three hard bounces of increasing severity. The third of these occurred with the landing gear already collapsed and structural damage and a consequential fuel-fed fire followed as the aircraft veered off the runway at speed. The subsequent evacuation was only partly successful and 41 of the 73 occupants died and 3 sustained serious injury. An Interim Report has been published.)
- DH8B, en-route, west northwest of Port Moresby Papua New Guinea, 2017 (On 4 August 2017, a de Havilland DHC8-200 was climbing through 20,000 feet after departing Port Moresby when a sudden loud bang occurred and the aircraft shuddered. Apart from a caution indicating an open main landing gear door, no other impediments to normal flight were detected. After a return to the point of departure, one of the main gear tyres was found to have exploded causing substantial damage to the associated engine structure and releasing debris. The Investigation concluded that tyre failure was attributable to FOD damage during an earlier landing on an inadequately maintained but approved compacted gravel runway.)
- RJ1H, vicinity Gothenburg Sweden, 2016 (On 7 November 2016, severe airframe vibrations occurred to an Avro RJ-100 which, following ground de icing, was accelerating in the climb a few minutes after departing from Gothenburg. The crew were able to stop the vibrations by reducing speed but they declared an emergency and returned to land where significant quantities of ice were found and considered to have been the cause of the vibrations. The Investigation concluded that the failure of the de icing operation in this case had multiple origins which were unlikely to be location specific and generic safety recommendations were therefore made.)
- B772, en-route, northern Indian Ocean, 2014 (On 16 April 2014, a pre-flight concern about whether a Boeing 777-200ER about to depart Singapore had been overfuelled was resolved by a manual check but an en-route fuel system alert led to close monitoring of the fuel system. When a divergent discrepancy between the two independent fuel remaining sources became apparent, an uneventful precautionary air turnback was made and overfuelling subsequently confirmed. The Investigation found that a system fault had caused overfuelling and that the manual check carried out to confirm the actual fuel load had failed to detect it because it had been not been performed correctly.)
- AN26, vicinity Cox’s Bazar Bangladesh, 2016 (On 29 March 2016, an Antonov AN-26B which had just taken off from Cox’s Bazar reported failure of the left engine and requested an immediate return. After twice attempting to position for a landing, first in the reciprocal runway direction then in the takeoff direction with both attempts being discontinued, control was subsequently lost during further manoeuvring and the aircraft crashed. The Investigation found that the engine malfunction occurred before the aircraft became airborne so that the takeoff could have been rejected and also that loss of control was attributable to insufficient airspeed during a low height left turn.)
- Decision Making
- Decision-Making (OGHFA BN)
- Fuel Dumping: Guidance for Flight Crews
- Fuel Dumping - Guidance for Controllers
- Engine Failure: Guidance for Controllers
- Engine Failure After TakeOff - Light Twin Engine Aircraft