Firewall depression at motor mount

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northtexasmaule
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Firewall depression at motor mount

Post by northtexasmaule »

Hi all,
I am a relatively new owner of a MT7-235 and am looking for some advice/recommendations. I took my plane in to get some avionics work done and an annual at the same shop at the same time.

However, the A&P pointed out a depression in the firewall at the lower motor mount on the copilot's side. He emailed Maule and sent some pictures. Maule recommended we unrivit the skin under the firewall and remove the flooring at the front to get a better idea what may be going on. However, when we did this, there are no bent tubes in this area. After sending pictures to Maule, they replied that sometimes the firewall needs to be bent at the engine mount point during install and that there was no structural damage they could see.

However, the A&P is now unwilling to sign off the plane and has proposed that we get a ferry permit to Maule to sign off. Has anyone in this forum had a similar issue with the firewall being depressed at the engine mount but no visible damage to the frame tubes at the front? The depth of the depression is about 1/2 inch, which to me initially indicated a wheelbarrow landing (even when I was a student I never landed nose first), but there is no damage to the front gear or engine mount. The one item to me that indicates the frame has not moved is that the aileron pulley and cable show no indication of being unaligned. Also the tubing at the front is square.

The A&P indicated that maybe the bent tube is behind this area, but Maule seems to think this is very unlikely.

Attached are some pictures for reference. Any ideas or recommendations for a second opinion that may be able to take a look? I am located in North Texas about 60mi east of Dallas.
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Mog
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Re: Firewall depression at motor mount

Post by Mog »

Check the vertical tube behind the firewall. Mine is slightly bent and my firewall is most certainly dimpled around the lower mount area. Just adds character 😉

northtexasmaule
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Re: Firewall depression at motor mount

Post by northtexasmaule »

Mog, who has been doing your annual? So far we can not find any bent tubes...

Thanks,
Rob

VA Maule
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Re: Firewall depression at motor mount

Post by VA Maule »

So this is a nose dragged with the little insurance wheel up front? :wink:

Looks like too fast an attempt to land a she took a purity good lick on the 3rd bounce. Take the engine mount bolt at the corner in question lose but not out check and see if you can put a wench on it and rotate it in place. Might need to use an engine hoist to relieve some of the tension or pressure weight. If the bolt won’t rotate without too much effort it’s bent if it is just take it apart and rebind it till it fits right. Don’t over rebind thought.
If your A&P won’t go shopping for a new one. So many nowadays are afraid to fix stuff just operate in replacement with new mode.
The best Government, is less Government.

northtexasmaule
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Re: Firewall depression at motor mount

Post by northtexasmaule »

VA Maule, we pulled the bolt and it is straight. We are stumped. Definitely could use another set of eyes if someone is willing to check it out in North Texas.

VA Maule
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Re: Firewall depression at motor mount

Post by VA Maule »

If the bolt is straight and free to rotate. Massage out the wrinkle to your liking , maybe a little filing of the firewall hole to relax the wrinkle , all Maules are individually made with lots of hand fitting work particular to each airframe.
Sure does look like a 3rd bounce wack though. If the cowling fits well it’s probably like Maule made it.
The best Government, is less Government.

netconn
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Re: Firewall depression at motor mount

Post by netconn »

Get another A&P

Cash
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Re: Firewall depression at motor mount

Post by Cash »

Northtexasmaule, is the plane still in annual? If so have I/A note his concerns on his bill or separate paper ( not logs) and get it out of there. He has no authority to ground plane and typical A/P I/A overreach. Also any A/P can work on your plane not just the factory. Georgia is a long way away. With all the Maules in Texas got to be several experienced A/P in Maules in Texas. If out of annual hopefully one will travel to you to sign off for flight to their location if A/P where you are won’t.
Flyrider

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gdflys
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Re: Firewall depression at motor mount

Post by gdflys »

Maybe something bumped into the boot cowl/cowling from the outside and bent the firewall? Other than keeping any fire up front and maintaining the shape of the boot cowl, the firewall has little to no structural strength importance. Its a tube and fabric fuselage and if the tubing is all straight and not cracked then it should be signed off.
Greg Delp
1979 M-5-235C
CT
ATP, CFI, A&P/IA

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