Please help. RV-7 and RV-9 Spar Question

[N601RX]

I looking for some information on the spar cross section on a RV7 and RV9. I'm not trying to build one, I just looking for some information to make some comparisons. I have a zenith 601xl and as some of you may know the wings have been coming off in flight. Will someone please share some dimensions on the cross section of the spar for a 7 and 9. I'm specifically interested in the height of the spar and the number and size of the upper and lower spar caps as well as rivet spacing and size. A picture would also be appreciated

Thanks,
Mike

[mcencula]

On my -7A, the spar cap bars measure at the root:

Bottom cap bar: 1.43 high/1.25 fwd-aft
Top cap bar: 1.5 high/1.25 fwd-aft

The spar cap bars are a single piece of aluminum. The thickness (fwd-aft direction) is stepped down several times from the root towards the wing tip, but I cannot take any measurements as my wings are completed.

That said, I don't believe these measurements will help in anything other than rough order of magnitude comparison with the 601. A real engineering analysis would need to be performed on the 601 wings to understand their loading...and even this will only be useful from a static and fatigue perspective. Any kind of flutter analysis would need to be based on empirical testing (note that I am not a flutter engineer).

[N941WR]

Mike,

Welcome to the VAF forum. Good luck with your plane, you guys are in a load of hurt right now.

Here is a picture of the aft spar of my -9. This is the doubler where it bolts to the fuselage.


And here is a picture of the main spar before the leading edge and fuel tank have been fited.


There are some other pictures on my web site. Shoot me an email, if you need more. I might have some pictures that I haven't posted.

Good luck getting through this.

Bill

[kiwipete]

Mike

I know that the United Kingdom 601's now have under gone a series of modifactions, structural and flight testing to get them airworthy again. It might be worthwhile contacting Francis Donaldson at:

http://www.lightaircraftassociation.co.uk/

They have done a huge amount of work on this and consulted the orginal manufactures etc.
see:

http://www.lightaircraftassociation....g_updates.html

Good luck

Peter

[Steve Barnes]

Mike check your Personal Messages