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is there a specific flap overspeed inspection?

danny

Well Known Member
Well there I was....doing touch and goes and totally fixating on different elevator trim settings for take off. The third take off felt way different than the others and I was probably 100-110 climbing out. It took a few moments to realize what was different...full flaps. It's a -9 so I wasn't a lot over. When I landed I ran the flaps up and down listening for strange noises and looking for anything different. I looked over, under, sideways, down (I'm a Yardbirds fan) and found nothing out of the ordinary.
I'm just wondering if there's anything else I should do? I have visions of a flap end tearing away and beating the fuselage up.
Is my anxiety enough or should I do more?
thanks
danny
 
Maybe use a straightedge or the equivalent to check for twist? I would think since the flap is lowered by a rod on the inboard edge it would twist if excessive force was applied over the whole span.
Greg RV9A N4603X
 
I don’t know about a specific overspeed checklist, but I would lower the flaps full, check that the pushrods aren’t bent and chafing on the fuse holes, and check that the attach bolt ball thing is not bent or loose. It’s a good idea to check these anyway. As for something specific, perhaps an email to Vans?
 
While I seriously doubt you did any damage, this is not the place to ask for anything but an opinion - for facts on structural questions, you need to check with Van’s.

Paul
 
I agree with Paul- structural questions should be put directly to Van's engineers. Please let us know what they say, as what you learn would benefit us all.
 
Well there I was....doing touch and goes and totally fixating on different elevator trim settings for take off. The third take off felt way different than the others and I was probably 100-110 climbing out. It took a few moments to realize what was different...full flaps. It's a -9 so I wasn't a lot over. When I landed I ran the flaps up and down listening for strange noises and looking for anything different. I looked over, under, sideways, down (I'm a Yardbirds fan) and found nothing out of the ordinary.
I'm just wondering if there's anything else I should do? I have visions of a flap end tearing away and beating the fuselage up.
Is my anxiety enough or should I do more?
thanks
danny
RELAX.. :D I have a background in stress analysis of airframes. No WORRIES. That is minor. Good for you being aware and diligent. However RV airframes have a fairly fat "margin of safety". Even though EAB (Kit plane not certified) it was designed, analyzed and constructed like a certified plane in may aspects (but not all).

This is NOT an excuse to exceed limits but aircraft are designed for the maximum expected load for worst case (limit load) and multiplied by a 1.5 ultimate load factor. You should NEVER exceed limit load and ultimate is a defined load which the airframe should never see. However it is there for safety and the chance of exceedance.

Now are flap loads proportional to speed. We can for sake of this discussion say, yes. You went 10% over. This is minor. However the 100MPH limit should be respected. We don't fly outside the envelope and use our safety margins intentionally, as you know. Fly within airframe limits. Also you should try and not run the plane RIGHT AT LIMIT all the time as this adds wear and tear.

Also the structure has extra strength or margin, as the design typically has an additional strength, a margin of safety over the required (limit or actual load x 1.5 ultimate load factor). You don't want to make the plane too heavy with excessive margin, but it is impossible to cut the margin to NET for every part of the plane.

In some cases this extra margin over the ultimate load factor is large, sometimes very small. However KEEP IN MIND. The plane is only as strong as the weakest link. What is the weakest link? I don't know but it varies with model. You can pull an RV apart if you over load it (G factor, speed). No plane is unbreakable. However your minor excursion is well within the "margin".

All of this is a little more complicated in actual practice of design and analysis, but short answer is no need to worry. Do a detailed visual inspection, look for anything out of normal, loose rivets, buckled or wrinkled skin, mechanical extension. The RV is fairly rugged. I predict you won't find anything that was not already there. A good inspection of whole airplane, laying on the ground, good light source, of the whole plane is a really good thing to do from time to time between condition inspections.
 
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