Another flap oddity

[Rich]

I didn't want to hijack Arnaud's flap thread, but it did motivate me to try to track down a problem I've had with my right flap.

When the flaps retract, the last couple of mm of trailing edge travel pushes up on the trailing edge of each wing. There is this little rectangular piece of what seems to be silicon-rubber underneath said trailing edge to cushion the pressure between the flaps and the composite of the wing. (Picture is from the left wing):

This is missing from my right wing, though it appears it was there at one time. This causes the composite trailing edge of the wing to gouge against the upper surface of the flap. There has been a workaround of some tape on the flap to keep it from being damaged. But now I know the actual cause. Naturally this doesn't appear in the online parts list, so I have an inquiry where I might find a replacement.

Has anyone else run into this?

[smoss]

No answer for you where to find the official part, but I have also noticed mine are getting pretty worn. Perhaps a piece of silicone rubber baffling material cut to shape would be perfect.

[Rich]

No answer for you where to find the official part, but I have also noticed mine are getting pretty worn. Perhaps a piece of silicone rubber baffling material cut to shape would be perfect.

It's not obvious from the picture, but this piece is thicker than baffle material. Then there's the issue of how to bond/glue it in place. The one on the left side has been there for 18 years. The right wing has been off and on the plane several times (the left only once). I figure that's when it somehow got knocked off.

[astaib]

I will check on mine shortly and will report if they are still in place.

Arnaud.

[Rich]

I dug through the AMM and discovered that the flaps pressing against the wing skin has a specification. In particular, it's to produce a preload with the flaps up on each of the flaps of roughly 7-11 lb. There's a procedure described in the AMM to measure this value.

[Don]

Would not the factory have the replacement part for this?

[Rich]

Would not the factory have the replacement part for this?

I would think so. I for a part number so I can get it ordered. No reply yet, except they did issue a case number. It's hardly an emergency. It's been this way for years.

[Boatguy]

Then there's the issue of how to bond/glue it in place.

The rubber gasket between the wing and the fuselage on my plane was lifting up and flapping around. I used 3M marine grade silicone sealant (clear) and it's now very securely fastened in place. You can order it from a lot of sources but I get it at West Marine.

So it sounds like you'll just need to attach a piece of suitable rubber or silicon with the sealant. You could also conceivably just use 6mm high dots of the sealant with no rubber at all to create a cushion between the flaps and wing.

[Rich]

Then there's the issue of how to bond/glue it in place.

The rubber gasket between the wing and the fuselage on my plane was lifting up and flapping around. I used 3M marine grade silicone sealant (clear) and it's now very securely fastened in place. You can order it from a lot of sources but I get it at West Marine.

So it sounds like you'll just need to attach a piece of suitable rubber or silicon with the sealant. You could also conceivably just use 6mm high dots of the sealant with no rubber at all to create a cushion between the flaps and wing.

Thanks. I'd like it to be the right thickness, hardness and elasticity so as to replicate the required preload. The wing skin acts as a kind of spring. It's hard to measure precisely, but remaining one seems to be about 2-3mm thick. The material seems similar to that seal that sits between the wing and wing center-section.

[Rich]

Response from Diamond. Now I know the spec. I think I have some of this stuff, along with an appropriate adhesive:

Hi Rich,
The bumper under the flap is a piece of rubber sheet, 1/8" thick. We sell the item under P/N P0011 by the sq. ft.
The rubber is not self adhering, you will need to apply some contact cement to the area for adhesion.
Regards,
Neil Grant
Fleet Support Manager