Can Anyone Identify These Strips?

[JGug1]

This is a P337 wing. You will recognize the Horton STOL parts and the VG's but what are these rows of strips. It has been suggested that they are stall strips. Any help?
JG

[AP AVM]

No those are not stall strips for sure. They kinda look like strap strips of some type...never seen something like this before of aircraft.

[JGug1]

It appears that you are suggesting that they
are to strengthen the wing. Is that the case?
I failed to mention that this 337 has Flint tip tanks, extending the
wing 2"(?) on each side.

[hharney]

I would suggest you check the logbook. I am not familiar with the strips but there better be something in the logs or an STC or something

Please let us know

[JGug1]

It looks, from the opinions of two IA's who are friends, that they are, in fact, stall strips. I will be talking to a definitively knowledgeable source tomorrow and will confirm their function. I was with the logs yesterday but do not have access today.
I do appreciate the input. This is such a helpful source.
JG

[JAG]

Those look like external straps (structural, not aerodynamic) on the wing - does not appear normal for a Cessna 337. Now if it was a Lockheed Electra - that would be a different story. To me, it looks like either a repair (337) or some structural improvement. Either way, it is not typical and should be avoided in my opinion.
Jeff

[JGug1]

JAG, I am inclined to agree with you. At the very least, they look horrible. Yes, painting them would cover much of that but there is no way they don't interfere with normal air flow over the wing and they HAVE to cost knots. I don't like them one little bit. I am seeking an explanation from the person who has the airplane.
Thank you.
JG

[JAG]

You could also do a records request on the aircraft (may not be filed yet if work just happened) from the FAA ($10) - this may provide the details of the 337 on those straps. Just an idea.
Jeff

[Kim Geyer]

I think its part of Flint Aero SB FA2

[JGug1]

Kim Geyer, you win. The prize is a stay at a Trump Hotel. This airplane has Flint tip tanks and the people at Flint are very helpful. Two years ago, you may recall, that Aviation Enterprises was required to pull their tip tanks. At that time, the Feds required a strengthening of wings of earlier 337's, the ones with the smaller tanks, if they had Flint Tip tanks. The straps are the only way Flint could discover to resolve the problem They were not required to have the tanks but they were required if you put fuel into the tanks. So, that mystery is solved. I don't like the looks of them one bit but now that there is an explanation, I don't feel quite as bad about them as I did.
Thank you all for your help.
JG

[Skymaster337B]

I wonder if this will be a requirement for all 337's in the future, in the form of an AD? Spare strap AD's seem to be the FAA solution to keeping 50+ year old airplanes in the air. Just a thought, since there's no economic solution for new wings.

[JGug1]

I spoke with the manufacturer of the Flint Tanks. He said that there is a "weak" point in the models made before '74 (?). If tip tanks are put on later models, they are not required. He also said that the '73's do have a "weakness" at that point but that Cessna had not found it problematic and requiring a fix. To clarify, the tip tanks make the wing more vulnerable in the earlier models. Apparently not so in the later models. 337's were found plenty strong in Vietnam.

[skymstr02]

Originally Posted by Skymaster337B

I wonder if this will be a requirement for all 337's in the future, in the form of an AD? Spare strap AD's seem to be the FAA solution to keeping 50+ year old airplanes in the air. Just a thought, since there's no economic solution for new wings.

Typically the spar straps go on the lower surface to be in tension vs. the upper surface (compression).