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

  • AT75, vicinity Cork Ireland, 2014 (On 2 January 2014, the crew of an ATR 72-212A lost forward visibility due to the accumulation of a thick layer of salt deposits on the windshield whilst the aircraft was being radar positioned to an approach at Cork on a track which took it close to and at times over the sea in the presence of strong onshore winds. The Investigation concluded that the prevailing strong winds over and near to the sea in relatively dry air with little visible moisture present had been conducive to high concentrations of salt particles at low levels.)
  • F50, Groningen Netherlands, 2007 (On 18 May 2007, a Fokker 50 being operated by Belgian airline VLM on a passenger flight from Amsterdam to Groningen landed long and at excessive speed after a visual day approach to runway 05 at destination and ran off the end of the runway onto grass. None of the 14 occupants were injured and the aircraft suffered only minor damage with two runway lights being damaged.)
  • E55P, Blackbushe UK, 2015 (On 31 July 2015 a Saudi-registered Embraer Phenom arriving from Milan on a private flight continued an unstabilised visual approach to Blackbushe UK in benign weather conditions to a landing. Touchdown occurred with almost 70% of the 1059 metre landing distance behind the aeroplane and it overran, sustaining terrain impact damage before an intense fuel-fed fire competed its destruction and led to the deaths of all four occupants.)
  • 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.)
  • B733, vicinity Belfast Aldergrove UK, 2006 (On 18 July 2006, a Boeing 737-300 being operated by a Spanish Airline commenced a daylight non precision approach with a 12 degree offset FAT towards Belfast Aldergrove but then made an unstable descent to 200 feet agl towards an unlicensed runway at a different airport before being told by ATC radar to go around. A further also unstable approach to the correct airport/runway followed. The Investigation noted that there were multiple cues indicating that an approach to the wrong airport was being made and was not able to establish any reason why two successive unstable approaches were not discontinued)
  • … further results


Stabilised Approach Awareness Toolkit for ATC

Further Reading

CANSO

Part of the Stabilised Approach Awareness Toolkit for ATC