Thursday, 12 November 2015
A TRAGIC ACCIDENT – CAN WE SIMPLY WRITE IT OFF AS “PILOT ERROR?”
(Acknowledgements: AIR FACTS/Richard Collins)
In 86% of fatal GA accidents in the USA “pilot error” is given as the cause. If only it were that simple! To use a rugby metaphor, it really starts with a “pilot fumble”. The ball is dropped, but the option is still there to recover, and the error does not actually occur until the pilot fails to do so. 10% of fatalities occurred on missed approaches or go-arounds, and as only a tiny percentage of total hours are flown while doing these procedures, they can be defined as being quite hazardous.
One more rugby metaphor: The practice of holding onto the ball with both hands when a potential hazard looms. In flying, we need a version of this, and it needs to be a pilot’s operating mode which becomes active before a time of potential stress becomes critical.
A go-around is a time for a burst of brilliance and fancy footwork, but you have to be locked, loaded and ready to deliver. There is a lot going on requiring heavy-duty pushing and shoving, which might be more apparent on a go-around than in other situations. For example, the more flap you have extended, the more aggressive you need to be.
There is also a need to think carefully about how you use the elevator trim as the manoeuvre unfolds. Elevator trim is speed-related, and an aeroplane will seek the speed for which it is trimmed. Flap retraction on a go-around, usually from full to take-off initially, will result in a pitch change. The trim for the full-flap approach speed is likely to be quite different from the trim required in the subsequent climb-out.
Better to leave the trim alone until the required changes in configuration have been made and until the airspeed is on the desired value, and then trim away the forces. Accept the increased pushing and pulling as a reminder of the difference between what the aeroplane wants to do and what you want it to do.
A pilot flying a go-around is at a disadvantage because, unless it is prompted by some conflict with other traffic, he or she has usually already messed up! Key indications were ignored, bad decisions were made, and the airplane was flown into a difficult situation.
A go-around is unlike a take-off, in that it usually starts with full flap and with the pitch trim set for a full-flap approach. Thus the aeroplane will be out of trim, and the reduction in flap will induce what feels like a sinking spell requiring a substantial change in pitch attitude with a correspondingly high stick force. After making the errors that got the aeroplane to such a bad place some pilots may exhibit a reluctance to be aggressive with the power and the controls, but this is a time for decisive action.
Some pilots may also like to maintain a nose-up trim throughout the landing process as they feel it keeps the pitch forces low, but pilots so doing could find themselves at a disadvantage should the landing have to be aborted.
Go-arounds, not only “touch-and-gos”, should thus get plenty of attention in both initial and refresher training.