Accident and Serious Incident Reports: WAKE

Accident and Serious Incident Reports: WAKE

A selection of articles in SKYbrary relating to events which included Wake Vortex Turbulence as a contributory factor. The events are organised according to the tagging system in place.

ICAO Standard Wake Separation prevailed

On 28 May 2006, a Vueling Airbus A320 encountered sudden significant turbulence at FL325 and, during a temporary loss of control, was forced down to FL310 before recovery was achieved. Seven occupants sustained minor injuries and there was some internal damage caused by an unrestrained cabin service cart. The origin of the disturbance was found to have been wake vortices from an Airbus A340-300 which was 10nm ahead and 500 feet above on the same airway but the Investigation found that the crew response had been inappropriate and could have served to exacerbate the effects of the external disturbance.

On 27 August 2018, an Airbus A320 level at FL 300 encountered unanticipated turbulence which caused one of the cabin crew to fall and sustain what was belatedly diagnosed as spinal fracture. The Investigation found that the aircraft had flown through the decaying wake vortex from an almost opposite direction Boeing 747-400F at FL310 which had been observed to cross what was subsequently found to be 13.8 nm ahead of the A320 prior to the latter crossing its track 1 minute 40 seconds later that coincided with a very brief period in which vertical acceleration varied between +0.19g and +1.39g.

On 7 January 2017, the crew of a Bombardier Challenger en route at FL340 over international waters between India and the Arabian Peninsula temporarily lost control of their aircraft approximately one minute after an Airbus A380 had passed 1,000 feet above them tracking in the opposite direction. The Investigation is ongoing but has noted that both aircraft were in compliance with their air traffic clearances, that a major height loss occurred during loss of control with some occupants sustaining serious injuries and that after successfully diverting, the structure of the aircraft was found to have been damaged beyond economic repair.

On 29 April 2014, an Embraer E170 being operated in accordance with ATC instructions in smooth air conditions suddenly encountered an unexpected short period of severe turbulence which led both members of the cabin crew to fall and sustain injury, one a serious injury. The Investigation concluded that the turbulence encountered, which had occurred soon after the aircraft began descent from FL110, was due to an encounter with the descending wake vortex of a preceding Airbus A340 which had been approximately 10 nm and 2 minutes ahead on the same track and had remained level at FL 110.

On 26 September 2009, a Piper PA28-140 flown by an experienced pilot was about to touch down after a day VMC approach about a mile behind an S76 helicopter which was also categorised as 'Light' for Wake Vortex purposes rolled uncontrollably to the right in the flare and struck the ground inverted seriously injuring the pilot. The Investigation noted existing informal National Regulatory Authority guidance material already suggested that light aircraft pilots might treat 'Light' helicopters as one category higher when on approach and recommended that this advice be more widely promulgated.

ICAO Standard Wake Separation not met

On 13 December 2011, an Airbus 320 was allowed to depart from runway 25C at Frankfurt on a left turning SID just prior to the touchdown of an A380 on runway 25L. The A380 had then initiated a low go around which put it above, ahead of and parallel to the A320 with a closest proximity of 1nm / 200 ft, in breach of the applicable wake vortex separation minima of 7nm / 1000ft. The Investigation found that there had been no actual encounter with the A380 wake vortices but that systemic ATC operational risk management was inadequate.

On 5 July 2015, as a Boeing 777-300ER was departing Melbourne, two Boeing 737-800s which were initially on short final for intersecting runways with their ground separation dependent on one receiving a LAHSO clearance, went around. When both approaching aircraft did so, there was a loss of safe terrain clearance, safe separation and wake vortex separation between the three aircraft. The Investigation attributed the event to the actions of an inadequately supervised trainee controller and inappropriate intervention by a supervisory controller. It also identified a systemic safety issue generated by permitting LAHSO at night and a further flaw affecting the risk of all LAHSO at Melbourne.

On 25 April 2013, the experienced pilot of an en-route motor glider which was not under power at the time and therefore not transponding observed a potentially conflicting aircraft in Class 'E' airspace near Frankfurt Hahn and commenced avoiding action. Although the glider was within their field of view, neither of the pilots of the other aircraft, a Boeing 737 in a descent, was aware of the proximity of the glider until it passed them on an almost parallel opposite-direction track 161 feet below them at a range of 350 metres as their aircraft was passing approximately 6,500 feet QNH.

On 15 December 1993, the crew of an IAI Westwind on a domestic passenger charter flight failed to leave sufficient separation between their aircraft and the Boeing 757 ahead on finals in night VMC and lost control or their aircraft which crashed killing all occupants and destroying the aircraft in the impact and post-crash fire.

Accepted ATC clearance not followed

none on SKYbrary

Own separation

On 26 September 2009, a Piper PA28-140 flown by an experienced pilot was about to touch down after a day VMC approach about a mile behind an S76 helicopter which was also categorised as 'Light' for Wake Vortex purposes rolled uncontrollably to the right in the flare and struck the ground inverted seriously injuring the pilot. The Investigation noted existing informal National Regulatory Authority guidance material already suggested that light aircraft pilots might treat 'Light' helicopters as one category higher when on approach and recommended that this advice be more widely promulgated.

On 15 December 1993, the crew of an IAI Westwind on a domestic passenger charter flight failed to leave sufficient separation between their aircraft and the Boeing 757 ahead on finals in night VMC and lost control or their aircraft which crashed killing all occupants and destroying the aircraft in the impact and post-crash fire.

On Monday 3 March 1997 at 1014 hours, privately owned and operated Cessna 185 encountered wake turbulence from previous departing aircraft, the pilot lost control of the aircraft at a height from which recovery was not possible and the aircraft descended to the ground.

Intrail event

On 28 May 2006, a Vueling Airbus A320 encountered sudden significant turbulence at FL325 and, during a temporary loss of control, was forced down to FL310 before recovery was achieved. Seven occupants sustained minor injuries and there was some internal damage caused by an unrestrained cabin service cart. The origin of the disturbance was found to have been wake vortices from an Airbus A340-300 which was 10nm ahead and 500 feet above on the same airway but the Investigation found that the crew response had been inappropriate and could have served to exacerbate the effects of the external disturbance.

On 29 April 2014, an Embraer E170 being operated in accordance with ATC instructions in smooth air conditions suddenly encountered an unexpected short period of severe turbulence which led both members of the cabin crew to fall and sustain injury, one a serious injury. The Investigation concluded that the turbulence encountered, which had occurred soon after the aircraft began descent from FL110, was due to an encounter with the descending wake vortex of a preceding Airbus A340 which had been approximately 10 nm and 2 minutes ahead on the same track and had remained level at FL 110.

On 26 September 2009, a Piper PA28-140 flown by an experienced pilot was about to touch down after a day VMC approach about a mile behind an S76 helicopter which was also categorised as 'Light' for Wake Vortex purposes rolled uncontrollably to the right in the flare and struck the ground inverted seriously injuring the pilot. The Investigation noted existing informal National Regulatory Authority guidance material already suggested that light aircraft pilots might treat 'Light' helicopters as one category higher when on approach and recommended that this advice be more widely promulgated.

On 10 January 2008, an Air Canada Airbus A319 en route over the north western USA encountered unexpected sudden wake vortex turbulence from an in trail Boeing 747-400 nearly 11nm ahead to which the pilots who then responded with potentially hazardous flight control inputs which led to reversion to Alternate Control Law and aggravated the external /disturbance to the aircraft trajectory with roll up to 55° and an unintended descent of 1400 feet which with cabin service in progress and sea belt signs off led to cabin service carts hitting the cabin ceiling and several passenger injuries, some serious.

On 27 June 2000 an Airbus A300-600 being operated by American Airlines on a scheduled passenger service from London Heathrow to New York JFK was being flown manually in the day VMC climb and approaching FL220 when a loud bang was heard and there was a simultaneous abrupt disturbance to the flight path. The event appeared to the flight crew to have been a disturbance in yaw with no obvious concurrent lateral motion. Although following the disturbance, the aircraft appeared to behave normally, the aircraft commander decided to return to London Heathrow rather than commence a transatlantic flight following what was suspected to have been an un-commanded flight control input. An uneventful return was made followed by an overweight landing 50 minutes after take off.

Cross track event

On 27 August 2018, an Airbus A320 level at FL 300 encountered unanticipated turbulence which caused one of the cabin crew to fall and sustain what was belatedly diagnosed as spinal fracture. The Investigation found that the aircraft had flown through the decaying wake vortex from an almost opposite direction Boeing 747-400F at FL310 which had been observed to cross what was subsequently found to be 13.8 nm ahead of the A320 prior to the latter crossing its track 1 minute 40 seconds later that coincided with a very brief period in which vertical acceleration varied between +0.19g and +1.39g.

On 25 April 2013, the experienced pilot of an en-route motor glider which was not under power at the time and therefore not transponding observed a potentially conflicting aircraft in Class 'E' airspace near Frankfurt Hahn and commenced avoiding action. Although the glider was within their field of view, neither of the pilots of the other aircraft, a Boeing 737 in a descent, was aware of the proximity of the glider until it passed them on an almost parallel opposite-direction track 161 feet below them at a range of 350 metres as their aircraft was passing approximately 6,500 feet QNH.

Intersection take off

On Monday 3 March 1997 at 1014 hours, privately owned and operated Cessna 185 encountered wake turbulence from previous departing aircraft, the pilot lost control of the aircraft at a height from which recovery was not possible and the aircraft descended to the ground.

Intersecting extended centrelines

none on SKYbrary

Intersecting runways

On 5 July 2015, as a Boeing 777-300ER was departing Melbourne, two Boeing 737-800s which were initially on short final for intersecting runways with their ground separation dependent on one receiving a LAHSO clearance, went around. When both approaching aircraft did so, there was a loss of safe terrain clearance, safe separation and wake vortex separation between the three aircraft. The Investigation attributed the event to the actions of an inadequately supervised trainee controller and inappropriate intervention by a supervisory controller. It also identified a systemic safety issue generated by permitting LAHSO at night and a further flaw affecting the risk of all LAHSO at Melbourne.

En-route event

On 27 August 2018, an Airbus A320 level at FL 300 encountered unanticipated turbulence which caused one of the cabin crew to fall and sustain what was belatedly diagnosed as spinal fracture. The Investigation found that the aircraft had flown through the decaying wake vortex from an almost opposite direction Boeing 747-400F at FL310 which had been observed to cross what was subsequently found to be 13.8 nm ahead of the A320 prior to the latter crossing its track 1 minute 40 seconds later that coincided with a very brief period in which vertical acceleration varied between +0.19g and +1.39g.

On 7 January 2017, the crew of a Bombardier Challenger en route at FL340 over international waters between India and the Arabian Peninsula temporarily lost control of their aircraft approximately one minute after an Airbus A380 had passed 1,000 feet above them tracking in the opposite direction. The Investigation is ongoing but has noted that both aircraft were in compliance with their air traffic clearances, that a major height loss occurred during loss of control with some occupants sustaining serious injuries and that after successfully diverting, the structure of the aircraft was found to have been damaged beyond economic repair.

 

For all accident reports held on SKYbrary, see the main section on Accident Reports.

Categories

Related Articles

SKYbrary Partners:

Safety knowledge contributed by: