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Contribution of Unstabilised Approaches to Aircraft Accidents and Incidents

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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 (FSF) 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 (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 Instrument Meteorological Conditions (IMC))
  6. visual approach
  7. circling approach

Aircraft Accidents and Incidents Related to Unstabilised Approach Listed on SKYbrary

  • D328, Norwich UK, 2012 (On 22 March 2012, a Scot Airways Dornier 328 left the side of the runway shortly after touchdown following an unstable visual sequel to a non precision approach at Norwich and then carried out a go around without further event. The aircraft was undamaged by the excursion but a runway edge light was broken. The subsequent Investigation noted the gross violation of Operator SOPs in respect of the way the initial approach had been conducted, the absence of necessary crew procedures following a serious incident and the absence of any OFDM programme.)
  • E145, Ljubljana Slovenia, 2010 (On 24 May 2010 the crew of a Regional Embraer 145 operating for Air France continued an unstable visual approach at Ljubljana despite breaching mandatory go-around SOPs and ignoring a continuous EGPWS ‘PULL UP’ Warning. The subsequent touchdown was bounced and involved ground contact estimated to have been at 1300fpm with a resultant vertical acceleration of 4g. Substantial damage was caused to the landing gear and adjacent fuselage. It was concluded that the type-experienced crew had mis-judged a visual approach and then continued an unstabilised approach to a touchdown with the aircraft not properly under control.)
  • B190, Blue River BC Canada, 2012 (On 17 March 2012, the Captain of a Beech 1900C operating a revenue passenger flight lost control of the aircraft during landing on the 18metre wide runway at destination after an unstabilised day visual approach and the aircraft veered off it into deep snow. The Investigation found that the Operator had not specified any stable approach criteria and was not required to do so. It was also noted that VFR minima had been violated and, noting a fatal accident at the same aerodrome five months previously, concluded that the Operators risk assessment and risk management processes were systemically deficient.)
  • CRJ9, San Sebastian Spain, 2013 (On 25 October 2013, the crew of a Bombardier CRJ 900 made an unstable visual daytime approach to San Sebastian which culminated in a hard landing of sufficient severity to trigger an inspection in accordance with the AMM. The inspection did not occur and the aircraft made a further revenue flight before the hard landing was reported and substantial landing gear damage was discovered. The unstable approach at a Category 'C' airport was found to have been flown by the First Officer contrary to applicable regulatory requirements.)
  • CRJ2, Vigo Spain, 2010 (On 25 February 2010, a Bombardier CRJ200 being operated by Air Nostrum on a domestic passenger flight from Bilbao to Vigo carried out an ILS approach to runway 20 in day VMC which culminated in a non standard touchdown during which one wing touched the runway. The ground contact and consequential minor damage was not appreciated at the time and was found during a subsequent ground inspection. None of the 23 occupants were injured.)

... further results


Stabilised Approach Awareness Toolkit for ATC

Further Reading

CANSO

Part of the Stabilised Approach Awareness Toolkit for ATC