Confidential Human Factors
Incident Reporting Programme
The Charity
Aviation
Maritime
GA1322
Initial Report
The TAF for nearest airfield included wind W/SW 25 gusting 40 and the ATIS was 250 36 G 42.
Landed on RWY27 uneventfully but on taxiing past hangar just prior to shutdown, a gust caused a wing to lift and the propeller touched the ground. Engine required shock-load inspection. Wind gusts locally may have been exceeding 60 knots. Normally fly PA32, but have considerable experience in C172. PA32 probably would have been OK due greater mass, lower wing and wider track. I failed to allow for this in planning but fundamentally the forecast was not reflective of the actual conditions. Lessons learnt: weather may be worse than forecast – be cautious. Failure to psychologically account for the lighter aircraft than usual (C172) with higher wing and narrower wheel track than in PA32. Don’t be complacent!
CHIRP Comment
We’re grateful to the reporter for giving us this frank and open report, and for their self-critical assessment of lessons learned. Given the gusty conditions forecast, they probably shouldn’t have operated the aircraft anyway but if you are operating in gusty or windy conditions then don’t just think about how to manage the take-off or landing but also think about the taxy as well. Funnelling of wind between hangars and other structures is a known issue and should be considered as part of a pilot’s TEM considerations in gusty/windy conditions. This can be a particularly significant issue for high-wing aircraft or tail-draggers, both of which can be more prone to the effects of gusty wind conditions on the ground. If you are taxying in gusty conditions then also think about placing the control column in an appropriate position to counter any gusts. Finally, note that forecasts of gusts are not amended until they exceed the current gust forecast by 10kts or the mean speed by 15kts (see Met Office guide ‘What TAF values really mean’), so gusts might be 9kts higher than in a TAF before it is changed and so this should also be considered in TEM assessments.
Key Issues relating to this report
Dirty Dozen Human Factors
The following ‘Dirty Dozen’ Human Factors elements were a key part of the CHIRP discussions about this report and are intended to provide food for thought when considering aspects that might be pertinent in similar circumstances.
Awareness – assimilation of the risks associated with gusty wind conditions.
Knowledge – understanding the potential for gusts to be greatly in excess of the TAF (by up to 9kts).
Complacency – not preparing for the conditions that were encountered (or might be encountered).