Plexiglass inspection covers on wings?

andrew phillips · #1 03-09-2007, 08:12 PM

Hi All, On the Diamond Eclipse I trained on they had plexiglass inspection covers for the aileron bellcrank and flap mechanism. You could see all the nuts and bolt (with torque seal) at every walk around. I thought it was a great idea. Has anyone done this on an RV...if so, have any pics?

Andrew Phillips
7A QB

Kyle Boatright · #2 03-09-2007, 08:24 PM

This has been suggested before. The response from Van's (possibly catalogued in the Matronics archive) was that the metal covers are part of the load bearing structure so don't deviate from the plans.

osxuser · #3 03-10-2007, 11:08 AM

Hear hear!, Part of the reason I didn't like the idea of going to fiberglass panels on the fwd deck, when those panels are cut for panel access in -7's or -9's. Stick with Aluminum.

Paul Eastham · #4 03-10-2007, 11:32 AM

Another reason not to do it: the cover plates bend a bit when screwed in, which can break the epoxy if that's what you used to attach the plexiglass.

alpinelakespilot2000 · #5 03-10-2007, 11:47 AM

Quote:

Originally Posted by andrew phillips

Hi All, On the Diamond Eclipse I trained on they had plexiglass inspection covers for the aileron bellcrank and flap mechanism. You could see all the nuts and bolt (with torque seal) at every walk around. I thought it was a great idea. Has anyone done this on an RV...if so, have any pics?

Andrew Phillips
7A QB

Can't comment on whether or not inspection panel covers are generally "load bearing" or not, as others have questioned above, but "23 Years of the RVator" (or whatever the most recent edition is) has a article about making plexiglass windows for the aft. fuse inspection panels. (Just read it last night--I think if the "fuselage" section of the book.) I highly doubt Van's would publish something in their "best of the RVator" collections if they didn't generally approve of the concept. It might be worth a specific call to Van's though.

If you get an answer I'm sure we'd all appreciate hearing what it is, because many of us would agree with you that being able to view them on preflight is a very good idea. Good luck.

Low Pass · #6 03-10-2007, 02:43 PM

Quote:

Originally Posted by alpinelakespilot2000

Can't comment on whether or not inspection panel covers are generally "load bearing" or not, as others have questioned above, but "23 Years of the RVator" (or whatever the most recent edition is) has a article about making plexiglass windows for the aft. fuse inspection panels. (Just read it last night--I think if the "fuselage" section of the book.) I highly doubt Van's would publish something in their "best of the RVator" collections if they didn't generally approve of the concept. It might be worth a specific call to Van's though.

If you get an answer I'm sure we'd all appreciate hearing what it is, because many of us would agree with you that being able to view them on preflight is a very good idea. Good luck.

5-6 yrs ago I spoke personally with Van's personnel (name Scott rings a bell) and he said the wing plates carried a structural load. What I took from this was that the loading of the panels should be considered. If one could design a sufficiently strong plate with a clear insert, go for it. I personally dumped my handy-dandy aileron & elevator inspection covers that had Lexan inserts for stock design solid aluminum.

gvgoff99 · #7 03-10-2007, 06:12 PM

I was wondering if I would actually take a GOOD look under there if I had the ability to do so. I also wonder how many aileron bell crank or rear boom failures have happened in the RV's and if some have happened would they have been picked up by a quick look through a piece of plexiglass? If the covers are structural it is a no brainer answer and if they're not then it seems like over kill to me to put in a (thin) piece of plexiglass. Since it is "experimental" one can do what they wish so mine is only an opinion.

dan · #8 03-10-2007, 06:25 PM

It has been a while, but last time I perused the RV accident history (http://www.rvproject.com/ntsb.html), I don't recall seeing control system failures. Lots of bad landings and bad decisions, but no loose bellcranks that I recall...

GAHco · #9 03-10-2007, 08:52 PM

Put it together right, use castellated nuts and cotter pins and then inspect it twice before closing it. Torque seal the rod end jam nuts.

If you worry allot

use MS17825 Castle nuts that also are a nylon insert locknut too. This or similar function nuts are used on all Helicopter controls and most turbine aircraft primary control systems.

Always do a Push Pull Rod, Rock and Roll Check on your pre flights.
Are the jam nuts tight? and does your Push Pull rod rotate freely and the same amount in both directions?

Do your ailerons sit in the same position that they are supposed to?

Are your travels symetrical?

If you are still concerned open that plate up and check it out, and make it right.

If after all this you want to see the hardware in its functioning enviroment without pulling the plates every time, dont use plexiglass it is structuraly close to nothing unless bonded in place. Lexan is much better, but unless tested against the aluminum plate, I couldnt say its good enough.

Somebody with much more time than I have will be the one to report on the final results. It would be interesting

mark manda · #10 03-10-2007, 09:34 PM

Yes-- if you're still interested about this next week, I'll post some picts.

I can't post from my weekend web browser.