Panel Alterations - Field Approvals?

[Bill Putney]

Has anyone gotten a Field Approval for your new Dynon panel? The Dynon STC covers the installation of all of the Dynon gear but I think that there still needs to be a 337 for the instrument panel itself. Some instrument panels (like the ones on the Bonanza's) are a load bearing component of the aircraft structure and need analysis, some panels only attach to the airframe to hold it in place and only need to be tested to make sure the panel does't come apart under typical loads. The last time I did a wholesale replacement of my instrument panel I proposed a way to do the replacement and the FSDO Maintenance Inspector signed off in box 3 of the 337 and that was it. My current FSDO Inspector seems to think he doesn't have specific guidance that will allow him to approve data for this alteration.

I'd like to know if others have made it through this process without employing a DER to approve the data. If you have a field approved 337 to install a new panel for your Dynon panel I'd love to get a copy of it. I think the Inspector just needs a little push and seeing that other FSDOs are approving these would help.

Thanks,

Bill

 

[Raymo]

The regs say it is up to the A&P to determine if something is a major or minor alteration. Check with him/her first.

 

[Bill Putney]

The regs say it is up to the A&P to determine if something is a major or minor alteration. Check with him/her first.

I am the A&P and the IA... The Major/Minor tests are a bit ambiguous. Sometimes it's very clear and sometimes it's a toss up. A&Ps can make the call but we are not infallible and we ultimately have to answer to "the Administrator" if we get it wrong. I have complete confidence in the panel design and in my airplane the panel is not a structural element. But, in the past, FSDO Inspectors have asked that I do a 337 for panel swap outs but have routinely accepted my data and signed off a field approval. I've changed FSDOs and it appears that my current PMI doesn't feel confident to make the judgement and wants me to employ a DER to make the call. That could be a long drawn out and expensive affair that I'd rather not embark on if I can avoid it.

 

[Raymo]

That's the story with most, if not all, FSDOs, these days. If not structural, as in your case, I (as an A&P) don't think it would be a major repair, but I agree, there is a lot of gray area. There is a FAA document available that better describes what they consider major. Mike Busch mentioned it in one of his webinars.

 

[Bill Putney]

When Bill O'Brien worked at the FAA as the General Aviation & Sport Aviation - National Resource Specialist, he was very influential at the Agency in trying to bring some sanity to those processes. He spoke frequently at IA renewal seminars and was actually available on the phone. Sadly he passed away some years ago and I think that hole he left was never effectively filled. He was more focused on how to help solve problems than constructing rationals for why any specific problem was just unsolvable. As a working mechanic, I really miss having someone like that to call on. He didn't always say what I wanted to hear but he didn't mince words and you could pretty much hang your hat on what he was telling you.

 

[airguy]

You didn't mention the make/model of aircraft - you could ask the manufacturer for a statement saying it's not structural and that should be good enough.

 

[Eugr]

Also, you don't need to replace the whole panel. We kept the structural elements of the original panel in my Bonanza and made a new overlay.

 

[Bill Putney]

It's a 1951 Ryan Navion. Ryan Aeronautical stopped making Navion's in 1952 and had moved on to other things and been acquired by Teledyne and then Northrup-Grumman. The current TC holder is Sierra Hotel Aero. But, it's clearly not structural. I'll probably go with a minor alteration and call it good. I was just curious what other folks were getting from their FSDOs.

Also, you don't need to replace the whole panel. We kept the structural elements of the original panel in my Bonanza and made a new overlay.

The Navion panel isn’t structural so there isn’t a structure with panels like the Bonanza. I need to replace the current Swiss cheese with a panel cut for the Dynon stuff.

 

[kellym]

It's a 1951 Ryan Navion. Ryan Aeronautical stopped making Navion's in 1952 and had moved on to other things and been acquired by Teledyne and then Northrup-Grumman. The current TC holder is Sierra Hotel Aero. But, it's clearly not structural. I'll probably go with a minor alteration and call it good. I was just curious what other folks were getting from their FSDOs.

The Navion panel isn’t structural so there isn’t a structure with panels like the Bonanza. I need to replace the current Swiss cheese with a panel cut for the Dynon stuff.

Given you have already made a black/white determination that the panel is not structural, all you need to do is use similar strength material to give the same support to whatever you put in the panel. IIRC, most run in the 0.060 to 0.090 aluminum alloy.
Sometimes it is worse asking for a blessing from a PMI that doesn't have a GA background, than just making the decision yourself.
Just my experience as an IA.
Kelly