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Difference between revisions of "Air Turnback"
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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
- B753, London Gatwick UK, 2014 (On 31 October 2014, indications of a malfunction of the right over wing emergency exit slide on take off were followed during the return to land by the complete detachment of the slide and un-commanded but controllable roll. The Investigation found that "a series of technical issues with the slide panel and carrier locking devices caused the slide carrier to deploy and the slide to unravel". Although an SB existed to address some of these issues, it had not been actioned on the aircraft. Two operational matters encountered during the Investigation were the subject of Safety Recommendations.)
- B752, vicinity New York JFK USA, 2016 (On 7 July 2016, a right engine fire warning was annunciated as a Boeing 757-200 got airborne from New York JFK and after shutting the engine down in accordance with the corresponding checklist, an emergency declaration was followed by an immediate and uneventful return to land. After an external inspection confirmed there was no sign of an active fire, the aircraft was taxied to a terminal gate for normal disembarkation. The Investigation found that a fuel-fed fire had occurred because an O-ring had been incorrectly installed on a fuel tube during maintenance prior to the flight.)
- 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.)
- A320, vicinity Perth Australia, 2015 (On 12 September 2015, an Airbus A320 autopilot and autothrust dropped out as it climbed out of Perth and multiple ECAM system messages were presented with intermittent differences in displayed airspeeds. During the subsequent turn back in Alternate Law, a stall warning was disregarded with no actual consequence. The Investigation attributed the problems to intermittently blocked pitot tubes but could not establish how this had occurred. It was also found that the priority for ECAM message display during the flight had been inappropriate and that the key procedure contained misleading information. These ECAM issues were subsequently addressed by the aircraft manufacturer.)
- 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.)
- A319, London Heathrow UK, 2013 (On 24 May 2013 the fan cowl doors on both engines of an Airbus A319 detached as it took off from London Heathrow. Their un-latched status after a routine maintenance input had gone undetected. Extensive structural and system damage resulted and a fire which could not be extinguished until the aircraft was back on the ground began in one engine. Many previously-recorded cases of fan cowl door loss were noted but none involving such significant collateral damage. Safety Recommendations were made on aircraft type certification in general, A320-family aircraft modification, maintenance fatigue risk management and aircrew procedures and training.)
- 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