The International Cessna 170 Association

Here is the panel cut..it was with hole saws and a drill press. For the first time it turned out ok. I need to add a few more holes for various instruments but overall this it. It is more than likely me noticing more than anyone but some of the holes are not right in line or a little high, little low etc. Bugs me but I dont know if it is enough to drive me to recut...

Standard 6 pack on the left, maybe cut a hole for a nav indicator, although using a KX125 I believe. Then on the left, top big hole tach and the rest engine instruments etc.

open to opinions please!

Mount instruments and check for interferences as soon as possible. The custom panel in my airplane has an instrument hole about 1/8" too low so the control tee hit the AI. It's clear the problem wasn't discovered until the panel was made, engraved, and painted. Rather than making a new panel they shimmed and tweaked to eliminate the interference. You'll never discover that kind of problem without a full assembly of all the parts.

A word of caution, the center of rotation on the T bar is behind the vertical face of the panel. This means as the yoke is moved forward, the T goes up. In fact if you push the yoke all the way forward, the top of the T is only a few inches from the top of the panel. The result is that there can be interference with some of the longer instruments in your stack. I would recommend double checking this before you go much further.

Keep in mind there is a reason Cessna didn't just lower the T bar and went through the extra work and cost to design a U or Y yoke. I haven't looked lately, but I thought the Association had copies of a couple 337's doing this. As long as you follow those 337's (and they are signed by the FSDO), you are using "approved data" and are good to go. Attach a copy to your 337 and send it in. (Theoretically. Some people read the regs differently, and I can't necessarily argue with them. It's a gray area.)

DEM

flyboy122 wrote:A word of caution, the center of rotation on the T bar is behind the vertical face of the panel. This means as the yoke is moved forward, the T goes up. In fact if you push the yoke all the way forward, the top of the T is only a few inches from the top of the panel. The result is that there can be interference with some of the longer instruments in your stack. I would recommend double checking this before you go much further.

Keep in mind there is a reason Cessna didn't just lower the T bar and went through the extra work and cost to design a U or Y yoke. I haven't looked lately, but I thought the Association had copies of a couple 337's doing this. As long as you follow those 337's (and they are signed by the FSDO), you are using "approved data" and are good to go. Attach a copy to your 337 and send it in. (Theoretically. Some people read the regs differently, and I can't necessarily argue with them. It's a gray area.)

DEM

Actually recent changes with regard to approved data now prohibit the use of 337's as approved data unless they were completed in the 50's. Like aircraft installations do not apply anymore, unfortunately. This was a FAA legal determination. I forgot the date on it but it is a recent change to the way the FAA does business. IA Renewal seminar is saying engineering data must be approved by DER and that is not a DAR!. I hope people still have a line on their favorite Fed because it is harder to get things done smoothly.Your mileage may vary. Please make sure you talk to the FAA on what they want before you start tearing into your aircraft.

Appreciate the advice from the folks that have dealt with this before. It appears it is getting more and more strict on what you can do. We had originally spoke with our "favorite" guy from the local FSDO and he was on board but had said it had to be sent up to Seattle engineering. Kind of jumping the gun as paperwork has been sent off, however If I have to go back to the original yoke height because of not being approved, I will just have to deal with it with a bit different of a panel. Personally I feel that the original height of the 170 yoke is a bit high anyhow.

kylegreen229 wrote:Appreciate the advice from the folks that have dealt with this before. It appears it is getting more and more strict on what you can do. We had originally spoke with our "favorite" guy from the local FSDO and he was on board but had said it had to be sent up to Seattle engineering. Kind of jumping the gun as paperwork has been sent off, however If I have to go back to the original yoke height because of not being approved, I will just have to deal with it with a bit different of a panel. Personally I feel that the original height of the 170 yoke is a bit high anyhow.

Kyle, may I suggest you establish a plan with your favorite guy that is willing to have you fill out the 337 with your plan.It is also best to offer options with an established voice of reason. It appears your favorite guy is old school. Keep him close. It is getting weird out there. Best approach is to ask you favorite guy, how can I accomplish this then follow your favorite guys advice to get it done. I wish my favorite guy did not retire thats how I got things done. D

Kyle, I recommend talking with Chris at Del-Air. He will be most helpful.

I have my guy and we have moved forward with all this. The standard T has been cut down 4" to fit a standard 6 pack as shown previously. It slides right under my heading indicator at the farthest forward throw with out interference. I will be able to put a KX125 nav/com at the top and my ipad mount "center stacked". Maybe even my transponder will fit it is looking close, need to order the ipad mount.

Here is a pic of what my panel is coming to be. Still working on the far left side to fill some space. Likely a clock and my intercom over there...

Well........my field approval was APPROVED today. I am beyond excited. Lower panel for controls is all cut in, both side panels complete, just need to finish my center area for installing radio, transponder and ipad mount. Field Approval.....approved. Awesome!

Kyle, great news congrats!

Looks great, but I'd add a 3-1/8" hole or change one of the 2-1/4". Right now there's no space for a CDI or an all-in-one engine monitor like CGR30. You may not be planning to install either, but someday you or the next owner might want to and it would be nice if it could be done without pulling the panel and machining it.

I appreciate the advice. I was originally going to put another large hole for a CDI but decided against it for various reasons. Mainly simplicity to be honest. It has a center stack design now for someone else wanting to change to a "U yoke" setup and put fancy radios top to bottom if they choose. I just wanted to update to a 6 pack on the left, ipad mount on the bottom center (to keep but shorten the T yoke) a comm and transponder above that. Each panel is separate and easy to pull off if I or someone wished to redo it and add/remove/change holes majorly. This plane will mainly be flow close to home base in the Idaho back country. Don't need a IFR platform for the weight and or cost. The Ipad is a nice tool and will suffice for what I need. The photo attached is everything cut in.

Hey Kyle,

Did you finish this project? I'm curious to see how it came out. I'm doing some long-range planning for my ADS-B upgrade and it is spiraling into a whole avionics upgrade, which is in turn making me consider building a new panel. I would love to put a nav/com and transponder in the center stack, ideally without modifying the yoke.

That's what I figured. I guess I was hoping that I would be able to jam a single radio way up at the top or something, but that doesn't make a lot of sense. Budget is always a consideration, so I'll probably end up building an 8 hole upper panel and keeping the radios at my knee.