If you wish to contribute or participate in the discussions about articles you are invited to join SKYbrary as a registered user

Contribution of Unstabilised Approaches to Aircraft Accidents and Incidents

From SKYbrary Wiki
Article Information
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

  • 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.)
  • A321, vicinity Islamabad Pakistan, 2010 (On 28 July 2010, the crew of an Airbus A321 lost contact with the runway at Islamabad during a visual circling approach and continued in IMC outside the protected area and flying into terrain after repeatedly ignoring EGPWS Terrain Alerts and PULL UP Warnings. The Investigation concluded that the Captain had pre-planned a non-standard circuit which had been continued into IMC and had then failed to maintain situational awareness, control the aircraft through correct FMU inputs or respond to multiple EGPWS Warnings. The inexperienced First Officer appeared unwilling to take control in the absence of corrective action by the Captain.)
  • A332 / RJ1H, vicinity Zurich Switzerland, 2004 (On 31 October 2004, a Loss of Separation occurred between an A330-200, on a low go-around from Rwy 14 at Zurich Switzerland, and an Avro RJ100 which had been cleared for take-off on Rwy 10 and was on a convergent flight path.)
  • CRJ2, Barcelona Spain, 2011 (On 30 July 2011, an Air Nostrum CRJ200 continued a significantly unstable visual approach to Barcelona in the vicinity of a convective storm to a point where the aircraft commander considered that a go around would be less safe than continuing the approach. In an attempt to regain a viable vertical profile from above, sustained and very high rates of descent were flown triggering a continuous 16 seconds of EGPWS Mode 1 PULL UP Warnings which were completely ignored. The resultant very hard landing caused structural damage to the aircraft and the sole cabin crew sustained a minor injury.)
  • E135, George South Africa, 2009 (On 7 December 2009, an South African Airlink Embraer 135 overran the recently refurbished wet landing runway at George after braking was ineffective and exited the aerodrome perimeter to end up on a public road. There was no fire and all occupants were able to evacuate the aircraft. The subsequent investigation attributed the overrun principally to inadequate wet runway friction following the surface maintenance activities and noted various significant non-compliances with ICAO Annex 14.)
  • … further results


Stabilised Approach Awareness Toolkit for ATC

Further Reading

CANSO

Part of the Stabilised Approach Awareness Toolkit for ATC