A321 & A346:Lemons Of Our Times?

[Winnerhofer]

Juggling Act

Another Data-Entry Error

Airbus A321-211. No damage. No injuries.
While departing from Manchester, England, the morning of April 29, 2011, for a flight to Crete with 223 passengers and eight crewmembers aboard, the commander noticed that the sidestick controller “felt heavy” on rotation. After the A321 lifted off the runway, he noticed an indication on his PFD that VLS, the lowest selectable speed providing an appropriate margin to the stall speed, was increasing abnormally.
“He reduced the pitch attitude and covered the thrust levers in case more power was required,” said the report by the U.K. Air Accidents Investigation Branch (AAIB). “The aircraft accelerated and climbed, but at a slower-than-normal rate.”
En route to Crete, the flight crew checked their takeoff performance calculations and found that they were incorrect. The commander filed an incident report, and investigators found that the commander inadvertently had read aloud the zero fuel weight, 69,638 kg (153,526 lb), from the load sheet, rather than the actual takeoff weight, 86,527 kg (190,759 lb).
Both pilots entered the incorrect takeoff weight and other data in their laptop computers, which calculated V1 as 131 kt, VR as 134 kt and V2 as 135 kt; the correct speeds were 155 kt for both V1 and VR, and 156 kt for V2. The data-entry error also resulted in a calculated power setting that was too low for the planned reduced-thrust, or flex, takeoff.
The report said that the crew did not thoroughly cross-check the takeoff performance calculations by the laptops against those by the FMS, which would have shown discrepancies in the takeoff weight and the “green dot speed,” the speed to be used if a takeoff is continued after an engine failure.
“There have been a significant number of reported incidents and several accidents resulting from errors in takeoff performance calculations around the world in recent years,” the report said (see, “Safety in Numbers”). “Industry awareness of the frequency of these errors has been raised, but a solution has yet to be found.”