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Contribution of Unstabilised Approaches to Aircraft Accidents and Incidents

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Category: Toolkit for ATC - Stabilised Approach Stabilised Approach Awareness Toolkit for ATC
Content source: EUROCONTROL EUROCONTROL
Content control: EUROCONTROL EUROCONTROL

Description

The Flight Safety Foundation established that unstabilised approaches were a causal factor in 66 % of 76 approach and landing accidents and incidents worldwide between 1984 and 1997.

It was found that many low and slow (low energy) approaches have resulted in controlled flight into terrain (CFIT) because of inadequate vertical position awareness. Low energy approaches may also result in "loss-of-control" or "land-short" events.

High energy approaches have resulted in runway excursions and also have contributed to inadequate situational awareness in some of CFIT accidents.

It was found that a crew’s inability to control the aircraft to the desired flight parameters (airspeed, altitude, rate of descent) was a major factor in 45 % of 76 approach-and-landing accidents and serious incidents.

Flight-handling difficulties have occurred in situations which included rushing approaches, attempts to comply with demanding ATC clearances, adverse weather conditions and improper use of automation.

Consequences

Unstabilised approaches can be followed by:

  1. Runway excursions
  2. Landing short
  3. Controlled flight into terrain
  4. Hard landings
  5. Tail Strike

Contributory factors

Weather conditions or approach types which can increase the chances of an unstabilised approach are:

  1. wake turbulence
  2. strong winds
  3. low visibility
  4. heavy precipitation
  5. an approach with no visual references (e.g. night or IMC)
  6. visual approach
  7. circling approach

Aircraft Accidents and Incidents Related to Unstabilised Approach Listed on SKYbrary

  • B744, Bangkok Thailand, 1999 (On 23 September 1999, a Boeing 747-400 being operated by Qantas on a scheduled passenger service from Sydney Australia to Bangkok overran Runway 21L during an attempted night landing in normal visibility and came to a halt substantially intact 320 metres beyond the runway end. There was no fire and a precautionary evacuation of the aircraft was not begun until 20 minutes after it came to rest. Only minor injuries were sustained by 38 of the 410 occupants, some during the initial runway excursion, others as a consequence of the evacuation. The aircraft remained substantially intact during the overrun although the nose landing gear and one main landing gear separated. The picture below, taken from the Official Accident Report, shows the aircraft in its final stopping position.)
  • A320, Khartoum Sudan, 2005 (On 11 March 2005, an Airbus A321-200 operated by British Mediterranean Airways, executed two unstable approaches below applicable minima in a dust storm to land in Khartoum Airport, Sudan. The crew were attempting a third approach when they received information from ATC that visibility was below the minimum required for the approach and they decided to divert to Port Sudan where the A320 landed without further incident.)
  • A320, vicinity Tel Aviv Israel, 2012 (On 3 April 2012, the crew of an Air France Airbus A320 came close to loosing control of their aircraft after accepting, inadequately preparing for and comprehensively mismanaging it during an RNAV VISUAL approach at Tel Aviv and during the subsequent attempt at a missed approach. The Investigation identified significant issues with crew understanding of automation - especially in respect of both the use of FMS modes and operations with the AP off but the A/T on - and highlighted the inadequate provision by the aircraft operator of both procedures and pilot training for this type of approach.)
  • B732, vicinity Resolute Bay Canada, 2011 (On 20 August 2011, a First Air Boeing 737-200 making an ILS approach to Resolute Bay struck a hill east of the designated landing runway in IMC and was destroyed. An off-track approach was attributed to the aircraft commander’s failure to recognise the effects of his inadvertent interference with the AP ILS capture mode and the subsequent loss of shared situational awareness on the flight deck. The approach was also continued when unstabilised and the Investigation concluded that the poor CRM and SOP compliance demonstrated on the accident flight were representative of a wider problem at the operator.)
  • B712, Darwin Australia, 2008 (On 7 February 2008, a Boeing 717-200 being operated by Australian airline National Jet on a scheduled passenger service from Nhulunbuy (Gove) to Darwin flew an unstabilised night visual approach at the destination and made a very hard landing. The landing roll was completed and the aircraft taxied to the terminal. None of the 94 occupants were injured but the aircraft was suffered substantial structural damage and damage to the left hand main landing gear.)
  • … further results


Stabilised Approach Awareness Toolkit for ATC

Further Reading

CANSO

Part of the Stabilised Approach Awareness Toolkit for ATC