Originally Posted by
First_Principal
Surprised no-one has answered before now - spar fatigue is the short answer. You could look up
this site for the AD & further info.
FWIW I learnt a little about aircraft structural fatigue from Nevil Shute's book
No Highway, which was an interesting read for a youngster of my time.
At the time of writing this I believe the subject of structural fatigue was fairly speculative but as he was an engineer of some repute I suspect there was a degree of experiential thesis there. Certainly the story pre-dated the Comet issues, but not to a huge degree.
Sorry for the drift, the main thing is to ensure your [prospective] Tommy is up-to-date with all its AD's (there are others) and well in time as this wing spar mod shows..!
FP.
Ahhh thank you
I do just wonder why, given all we know about metal stresses, loads, fatigue etc, that this is still a problem? Hmm.
Originally Posted by
Pilot DAR
Airframes are intended to flex under load, and the limitations are very clear. When my buddy and I used to dogfight in our 150's, I was amazed to be chasing him around in a 3G turn (yes, I have a G meter), to see the sun light up the top of his wings - the wrinkles in the skin, tip to tip, were profound. Once on the ground again, a quick, nervous check, and everything looked perfectly normal.
Yes, the tail of a Tomahawk wobbles around a bit during a spin (which I did many times), and during flight in turbulence too. As the pilot, ask yourself: Why are you watching backward while you're flying forward? Don't worry about it!
I can definitely vouch for the flexibility of airframes... Aeros in a rented C152 which regularly made the door pop open mid-flight. Yay(!) Airframe was twisting enough that the latch would just pop right out of the lock... of course could never reproduce on the ground. I believe they had to take one of the maintenance guys up for a couple of loops to show him the problem
The plane was well-known for it. Also it's slightly lop-sided yoke position. Ahh the little foibles we come to know and love...!