Flap Overspeed RV7A

[Tcheairs]

Took off yesterday with full flaps (inadvertently). I have an excuse but it doesn't matter so please don't ask..Was at 130kias before I realized what was going on. Retracted the flaps and proceeded to cruise flight. Noticed slight vibration which unfortunately is something new for my RV7A.

What components of the flap system are most likely to have been damaged due to this bonehead stunt? How should I proceed with an inspection. Does anyone have a drawing of the system that they could share..I am not the builder of this (once) beautiful airplane..

Sadly..Thanks..

[BH1166]

Ive done the same, but never got to that speed with full flaps ! Thats fast with all that drag. I personally think you are fine, no harm to plane. Also I believe there is much more potential for damage doing 130 and deploying full flaps . If they retract and extend , and the trailing edge looks in alignment, my opinion is go fly, forget about it. Many post over the years on this, I never recall reading of damage, other than ego :-)

[Sam Buchanan]

Rest assured you are not the only RV pilot to blow past flap speed.

Most likely there is no damage to the airframe but the first thing you want to check is the flap pushrods to make sure they aren't bent. Not sure about the vibration, maybe an issue with the pilot instead of the airplane?

You need to order the plans for your aircraft so you and your mechanic have them for servicing questions. You can get them for a minimal price on a thumb drive from the Vans store.

[Tcheairs]

There is now a noticeable vibration in flight with the flaps retracted which has never existed before. Thought it might be the engine as it just came out of annual which was done by a very reputable shop. (no engine vibration noted on engine runup). I have not had an opportunity to start troubleshooting (flap alignment and rods) today yet, but I will do so.

[plehrke]

Check everything in the flap retraction system. Actuators, Push rods, weldments, bearings, bolts. Look for anything that looks bent and any type of freeplay. Your vibration could be the flap flapping due to something bent and causing freeplay.

Thread Drift, do builders that sell their RVs not include the plans, manuals, and builder notes with the sale? I guess I would not buy one if they were not included.

[Tcheairs]

I do have a complete set of builder's plans..I'll go through them before I inspect
the system..

[Carl Froehlich]

Time for a full inspection. Off the top of my head:
- With the flaps fully up, use a straight edge across the wing skin and flaps. Look for variances between the two flaps and for variances inboard to outboard on each flap.
- Lower the flaps and look for new vibration marks on the bottom of the fuselage where the flaps tuck in when fully retracted.
- Remove the flap rod and drop the flaps so you can check the flap hinge. Look for broken or bent hinge eyes.
- If anything looks odd, pull the flap hinge pin and inspect the flap on the bench, and further inspect the flap hinge half on the wing trailing edge.
- As previously discussed, inspect the removed flap rod to see if it is still straight.
- Inspect the flap rod fuselage pass through hole to see if the flap rod has been rubbing it.

Let us know what you find.
Carl

[MacCool]

Originally Posted by Carl Froehlich

Time for a full inspection. Off the top of my head:
- With the flaps fully up, use a straight edge across the wing skin and flaps. Look for variances between the two flaps and for variances inboard to outboard on each flap.
- Lower the flaps and look for new vibration marks on the bottom of the fuselage where the flaps tuck in when fully retracted.
- Remove the flap rod and drop the flaps so you can check the flap hinge. Look for broken or bent hinge eyes.
- If anything looks odd, pull the flap hinge pin and inspect the flap on the bench, and further inspect the flap hinge half on the wing trailing edge.
- As previously discussed, inspect the removed flap rod to see if it is still straight.
- Inspect the flap rod fuselage pass through hole to see if the flap rod has been rubbing it.

Let us know what you find.
Carl

Good review, thanks. For reasons that are unclear, my recently-upgraded AFS EFIS now only displays fully up, or fully down flaps. Partial flaps show only as fully retracted. I recently took off with flaps incompletely retracted (they were about 10-15 degrees down) and discovered that in cruise, well above my flaps speed of 90 kts. Glancing at them over my shoulder while banking out of the pattern didn’t suggest to me that they might be deployed at all. I don’t think there’s any damage but Carl’s post clarified what I should be looking for.

[Carl Froehlich]

Originally Posted by MacCool

SNIPI recently took off with flaps incompletely retracted (they were about 10-15 degrees down) and discovered that in cruise, well above my flaps speed of 90 kts.

Partial flap speed is higher than the standard 87kt specification but I do not have any numbers for you. I vaguely recall something from Van’s on this.

I have the Showplanes flap position system and tend to put out one notch when entering downwind when below 95kts or so. I like to have full flaps out before turning base.

Carl

[Bavafa]

Just a few random thoughts;
- Does the in flight vibration changes by speed? Does it changes by RPM?
- Is there any movement of the flap when on the ground?
- Is there any noticeable twist/deformation of the flap? (This should affect how the plane flies straight or not and if it has a wing heavy tendency)

Anyway, grab your flap trailing edge and see if there is any movement both retracted or deployed. There should be very little, if any at all, movement.
The weakest part of the flap system, I believe is the round push rods unless they were upgraded to the hex version.
Also you can visually look at the piano hinge that attaches the flap to the wing and see if you observe any deformation or issues. Lastly, take a look at the rod end bearing and make sure the jam nut is tightly in place.

Good luck