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Air Turnback

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Category: General General
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Description

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

  • A320, Auckland New Zealand, 2017 (On 27 October 2017, an Airbus A320 returned to Auckland after advice from ATC that the right engine may have been affected by ingestion of FOD during engine start - a clipboard and paper left just inside the right hand engine by an employee of the airline’s ground handling contractor acting as the aircraft loading supervisor. The subsequent inspection found paper throughout the engine and minor damage to an engine fan blade and the fan case attrition liner. The Dispatcher overseeing the departure said she had seen the clipboard inside the engine but assumed it would be retrieved before departure.)
  • MD81, vicinity Stockholm Arlanda Sweden, 1991 (On 27 December 1991, an MD-81 took off after airframe ground de/anti icing treatment but soon afterwards both engines began surging and both then failed. A successful crash landing with no fatalities was achieved four minutes after take off after the aircraft emerged from cloud approximately 900 feet above terrain. There was no post-crash fire. The Investigation found that undetected clear ice on the upper wing surfaces had been ingested into both engines during rotation and initiated engine surging. Without awareness of the aircraft's automated thrust increase system, the pilot response did not control the surging and both engines failed.)
  • B735, vicinity Madrid Barajas Spain, 2019 (On 5 April 2019, a Boeing 737-500 crew declared an emergency shortly after departing Madrid Barajas after problems maintaining normal lateral, vertical or airspeed control of their aircraft in IMC. After two failed attempts at ILS approaches in unexceptional weather conditions, the flight was successfully landed at a nearby military airbase. The Investigation found that a malfunction which probably prevented use of the Captain’s autopilot found before departure was not documented until after the flight but could not find a technical explanation for inability to control the aircraft manually given that dispatch without either autopilot working is permitted.)
  • A320, vicinity Tallinn Estonia, 2018 (On 28 February 2018, an Airbus A320 would not rotate for a touch-and-go takeoff and flightpath control remained temporarily problematic and the aircraft briefly settled back onto the runway with the gear in transit damaging both engines. A very steep climb was then followed by an equally steep descent to 600 feet agl with an EGPWS ‘PULL UP’ activation before recovery. Pitch control was regained using manual stabiliser trim but after both engines stopped during a MAYDAY turnback, an undershoot touchdown followed. The root cause of loss of primary pitch control was determined as unapproved oil in the stabiliser actuator.)
  • 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.)
  • A332, vicinity Brisbane Australia, 2013 (On 21 November 2013, an A330 rejected its take off from Brisbane after an airspeed indication failure. Following maintenance intervention, a similar airspeed indication fault on the subsequent departure was reported to have been detected after V1. Once airborne, reversion to Alternate Law occurred and slat retraction failed. After an air turnback, it was discovered that the cause of both events was blockage of the No. 1 Pitot Head by a mud-dauber wasp nest which was created during the initial two hour turnround at Brisbane. Investigation of a 2014 event to a Boeing 737 at Brisbane with exactly the same causation was noted.)

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