Report: Virgin A346 at London Heathrow on Dec 12th 2009, false weight used for takeoff computations, degraded performance on takeoff
By Simon Hradecky, created Thursday, Jul 8th 2010 12:18Z, last updated Thursday, Jul 8th 2010 12:18Z
A Virgin Atlantic Airbus A340-600, registration G-VYOU performing flight VS-23 from London Heathrow,EN (UK) to Los Angeles,CA (USA) with 282 passengers and 16 crew, was preparing for departure, when a late change of the zero fuel weight occurred prompting the crew to request a new flight plan. After receiving the updated flight plan the crew erroneously used the estimated landing weight for computing their takeoff data instead of the takeoff weight while planning for a flex takeoff at reduced thrust. The pilot flying noticed a slower than normal acceleration during the takeoff run but did not consider the acceleration abnormal. The rotation was slightly sluggish and nose heavy, the airplane did not achieve V2 prompting the pilot flying to lower the nose and climb at 500-600 fpm. Flaps were retracted on schedule. Only later into the flight the crew reviewed the load sheet and recognized their error. The airplane continued to Los Angeles for a safe landing.
The British AAIB released their final report stating, that the crew used the estimated landing weight of 236 tonnes instead of the actual takeoff weight of 322.5 tonnes for computing the takeoff performance resulting in a Vr of 143 and V2 of 151 knots instead of the correct values Vr=157 and V2=167 knots. The lower weight also resulted in a flex takeoff temperature of 74 degrees C instead of the correct 63 degrees C. The crew was puzzled by the unusually high flex takeoff temperature, however did not recheck the takeoff data. Zero Fuel weight and fuel were correctly entered into the flight management and guidance system resulting in correct gross weight data.
The AAIB annotated, that at no time full thrust was selected during the takeoff and initial climb.
The airline assessed, that time pressure following the late zero fuel weight change contributed to the error. The landing weight was an acceptable takeoff weight. Due to the time pressure the crew did not compute an estimated takeoff weight on their own and compared this with the flight plan data. The cross checks performed by the crew were ineffective.
Da avherald.com.
By Simon Hradecky, created Thursday, Jul 8th 2010 12:18Z, last updated Thursday, Jul 8th 2010 12:18Z
A Virgin Atlantic Airbus A340-600, registration G-VYOU performing flight VS-23 from London Heathrow,EN (UK) to Los Angeles,CA (USA) with 282 passengers and 16 crew, was preparing for departure, when a late change of the zero fuel weight occurred prompting the crew to request a new flight plan. After receiving the updated flight plan the crew erroneously used the estimated landing weight for computing their takeoff data instead of the takeoff weight while planning for a flex takeoff at reduced thrust. The pilot flying noticed a slower than normal acceleration during the takeoff run but did not consider the acceleration abnormal. The rotation was slightly sluggish and nose heavy, the airplane did not achieve V2 prompting the pilot flying to lower the nose and climb at 500-600 fpm. Flaps were retracted on schedule. Only later into the flight the crew reviewed the load sheet and recognized their error. The airplane continued to Los Angeles for a safe landing.
The British AAIB released their final report stating, that the crew used the estimated landing weight of 236 tonnes instead of the actual takeoff weight of 322.5 tonnes for computing the takeoff performance resulting in a Vr of 143 and V2 of 151 knots instead of the correct values Vr=157 and V2=167 knots. The lower weight also resulted in a flex takeoff temperature of 74 degrees C instead of the correct 63 degrees C. The crew was puzzled by the unusually high flex takeoff temperature, however did not recheck the takeoff data. Zero Fuel weight and fuel were correctly entered into the flight management and guidance system resulting in correct gross weight data.
The AAIB annotated, that at no time full thrust was selected during the takeoff and initial climb.
The airline assessed, that time pressure following the late zero fuel weight change contributed to the error. The landing weight was an acceptable takeoff weight. Due to the time pressure the crew did not compute an estimated takeoff weight on their own and compared this with the flight plan data. The cross checks performed by the crew were ineffective.
Da avherald.com.
