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Thursday, February 28, 2013

● LIBYA: LYCAA releases final report on crash of Afriqiyah 771; blames lack of pilot coordination, somatogravic illusions.

AfriqiyahLibya's Civil Aviation Authority has released its final report on the crash of the Afriqiyah Airlines (8U) Airbus A330-200 (MSN 1024 | 5A-ONG) operating as flight 8U772 from Johannesburg, South Africa to Tripoli, Libya, which crashed on approach into Tripoli International Airport in May 2010. According to their findings, air crash investigators have blamed "the limited coordination and cooperation between the two crew members" exacerbated by fatigue and coupled with  the effects of somatogravic illusions (i.e. an optical illusion that can result in spatial disorientation) as the mitigating factors in the crash.

Backround

Afriqiyah Airlines (8U) Airbus Crash 771
The ill-fated Afriqiyah Airlines (8U) A330
On 12 May 2010, Flight 8U771 had on board three cockpit crew (who had flown the exact same flight on the exact same aircraft on 28 April 2010), eight cabin crew, and 93 passengers, with 50'000 Kgs of fuel during its take-off roll. 
After an uneventful flight from Johannesburg, the crew, during final approach towards runway 09 at Tripoli  International Airport, announced a go-around and initiated the Missed Approach Procedure, with the knowledge and confirmation of  Tripoli tower. Prior to the go-around, the accident crew had received information from an aircraft that had landed before them, warning them about fog patches during short finals.

During the Missed Approach phase, the Aircraft responded to the crew’s inputs with velocity and altitude increasing above the Minimum Descent Altitude (MDA). 
"The captain then instructed the co-pilot to execute a go-around, after which he informed the Tower controller. The aircraft began to climb, reaching an altitude of 450 feet above ground level. The Airbus then nosed down, causing the captain to take priority over the flight controls by pushing on priority button and the aircraft was fully under the captain’s control who applied a sharp nose down input. The captain did not verbally state that he was taking control. He applied a pitch-up and a pitch-down input on his stick."
Source [AviationSafety]

However, shortly before touchdown, at 04h01Z, the aircraft descended dramatically and impacted the ground about 1'200 meters short of runway 09's threshold and 150 meters right of the runway centre line.

The impact and post impact fire completely destroyed the Aircraft with only one passenger in seat 12D, a boy, surviving the crash, albeit with serious injuries.

Aftermath

Afriqiyah 771 Crash Tripoli

Afriqiyah 771 Crash Tripoli


Afriqiyah 771 Crash Tripoli

Afriqiyah 771 Crash Tripoli - AFP
Afriqiyah 771 Crash Tripoli - AFP

Causes

(Libyan Civil Aviation Authority - LYCAA)
(Libyan Civil Aviation Authority)

According to the Report, the most likely causes for the crash were:   

A final approach carried out in common managed guidance mode should have relieved the crew of their tasks. The limited coordination and cooperation between the two crew members, especially the change into Vertical Selected Guidance mode by the Pilot flying, probably led to a lack of a common action plan. 

The lack of feedback from the 28 April 2010 flight, flown by the same crew on the same aircraft, did not allow  them  to anticipate the potential risks associated with managing non-precision approaches. 

The pilots’ performance was likely impaired because of fatigue, but the extent of their impairment and the degree to which it contributed to the performance deficiencies that occurred during the flight cannot be conclusively determined. During  the  go-around,  the  crew  was  surprised not  to  acquire  visual  references.  

On one hand, the crew feared  exceeding  the aircraft’s speed limits in relation to its configuration, and on the other hand they were feeling the effects of somatogravic illusion due to the aircraft's acceleration. This  probably explains the aircraft handling  inputs, mainly nose-down inputs, applied during the go-around. These inputs were not consistent with what is expected in this flight phase. The degraded Cockpit/Crew Resource Management - CRM did not make it possible for either crew member to identify and recover from the situation before the collision with the ground, even when the TAWS (Terrain Awareness and Warning Systems) warnings were activated close to the ground.


Based on elements from the investigation, the accident resulted from:
  • The lack of common action plan during the approach and a final approach continued below the Minimum Descent Altitude (MDA), without ground visual reference acquired.
  • The inappropriate application of flight control inputs during a go-around and on the activation of TAWS (Terrain Awareness and Warning Systems) warnings,
  • The lack of monitoring and controlling of the flight path. 
These events can be explained by the following factors: 
  • Limited  CRM (Cockpit/Crew Resource Management) on  approach  that  degraded  during  the  missed  approach. This degradation  was  probably  amplified  by  numerous  radio-communications during  the final approach and the crew’s state of fatigue,
  • Aircraft control inputs typical in the occurrence of somatogravic perceptual illusions, 
  • Inappropriate  systematic analysis of  flight  data and feedback mechanisms at Afriqiyah Airways. 
  • Non adherence to the company operations manual, standard operational procedures and standard terminology. 
In addition, the investigation committee found the following as contributing factors to the accident:
  • Weather available to the crew did not reflect the actual weather situation in the final approach segment at Tripoli International Airport. 
  • Inadequacy of training received by the crew,
  • Occupancy of tower frequency by both air and ground movements control.
 Source [The Libyan Civil Aviation Authority]

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