12 - More about Flight Testing newly built aeroplanes

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Hello again folks,

I recently got this further info from SAAA test pilot Keith Engelsman:

'One thing I missed out in the notes is the importance of establishing longitudinal trim before take-off on the first flight.

I did a first flight in a Glasair IIRG a couple of years ago, and having set the trim during the high speed taxi runs, had no problem with the first take-off. Next day the owner decided it was time to try out his new toy, and invited a mate who owned the same type along to start conversion training. Amongst the several errors of judgement in this whole exercise (2 people, no weight and CG calculation etc...) was that he had done some sort of adjustment to the trim control. They did not bother with any high speed runs, and on take-off the aircraft tried to do a loop as soon as it left the ground. They only saved themselves by lots of grunt on the stick and frantic rotation of the trim wheel.

It's not that hard to get it right, as during high speed taxi tests you will get up to nose/tail wheel lift-off, and a bit of time making sure you have the trim set right will mean there should be no surprises when you finally leave the ground. Even if you have a fixed elevator trim tab, you can still make adjustments to have it about right for lift off and initial climb.

You might like to pass this tip on. All being well, I'll be at Naromine next Easter - hope to see you there.'

Regards Keith

Bob Grimstead
SABC Safety Committee