Reaction on hitting a bump
Could someone please tell me what will happen in the following scenario: taildragger, during the take-off run on a grass runway, has its tail raised and is close to flying speed, when it hits a bump. Will it pitch nose-up or nose-down?
My own thought is that it will pitch down. The centre of gravity is behind and above the main wheels, and all pivoting will take place around the main wheels. The momentum of the aircraft will cause the centre of gravity to continue to move forwards, and thus rotate around the main wheels, causing the nose to dip.
However, I've had an e-mail from someone suggesting the opposite - that the aircraft will pitch up. This comes from someone who knows what he's talking about - a very exerienced pilot, instructor and test-pilot who regularly flies everything from Tiger Moths to 777s. Although he said the aircraft would pitch up, he didn't explain why.
I will be meeting this person in a couple of weeks, and I'll ask him to explain why he thinks the aircraft will pitch up. Unless, of course, someone else can explain it to me before then!
Cheers,
FFF
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