Safety bulletin advises risk analysis of take-off checks.
Procedures to stop crews using erroneous information must be investigated, authorities say European safety authorities are recommending that carriere undertake a risk analysis of procedures to prevent crews using erroneous take-off parameters.
The European Aviation Safety Agency says the dedicated analysis should take particular account of the probability of using the wrong reference data for computerised performance calculations, incorrect transcription to flight- management systems, and inadequate cross-checking.
Carriers should emphasise, during pilot training, the need for consistency checks and “rules of thumb” to enable them to carry out a “mental gross error” check.
It also says that operators should highlight situational awareness during take-off, to assist crews in detecting sluggish acceleration and runway positioning, and implement specifěc flight-data monitoring relevant to take-off performance, EASA states, in a safety information bulletin, that incorrect weight or take-off performance data has contributed to a number of accidents and serious incidents.
EASA’s bulletin concentrates primarily on errors made by crews when entering data into the flight-management system or electronic flightbag. It says the main contributing human factors involved are time pressures and interruption of tasks, adding that the aircraft can suffer a tail-strike, overrun or even a catastrophic event.
Among the more common mistakes are the use of zero-fuel weight rather than actual take-off weight, the transposition or incorrect transcription of weight centre-of-gravity, or reference speed thresholds, and use of the wrong flap settings or incorrect values from performance charts.
EASA adds that aircraft data from a previous flight might be used, or take-off parameters are not updated during a change in operational conditions.
“Even if it can be assumed that the vast majority of errors were detected and corrected by the involved personnel, it is likely that several other events have occurred and have not been reported” says the authority.
Operators should collect more data on the issue, it says, to give a real picture of the problem.
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