Rear edge stiffeners ?

[Dave S]

Harlan,

I believe the instructions to include the aluminum tubes as an option was mentioned in my build manual (early S7); and, at the time I ordered them from aircraft spruce following the demise of skystar.

I see the addition as a way to increase the ruggedness of the trailing edge as well as dealing with the fabric shrinking stress as mentioned in the manual. I have seen way too many OOPS! happen in various hangars with visitors and I would rather see a dent in the perpetrator than the wing if at all possible.

Overall I think it is well worth the trouble but everyone's mileage certainly varies. Regarding weight - I just try to avoid eating too much stuff I shouldn't.

[Jerrytex]

Anyone know the size of this tubing 3/8" OD? What about wall thickness?

Thanks.

[Dave S]

Jerry,

The length can be measured between the ribs. The instruction, which are buried as a Note under the wing covering section say tubing wall thickness of 0.028" to 0.035". I used the 0.035" as the difference in weight is almost irrelevant (like eating 1/2 a bagel less for breakfast); and, once the tubes are bonded in, nobody is going to take them out and replace them after covering if they change their mind. No problem with bending with max shrink on the 0.035" wall thickness tubes.

[Jerrytex]

Thanks Dave.

I looked for this info in the manual and must have looked right at it 5 times.......

[Dave S]

Thanks Dave.

I looked for this info in the manual and must have looked right at it 5 times.......

Hi Jerry,

Well, it takes some sleuthing in the manual - they reference the stiffeners in the wing build section but do not include the wall thickness there. Then, cleverly hidden in the note section within the covering portion they have the dimensions - it's a trick!

Take care, Dave