Bottom Rear Cowl LH Hinge Broke 124.5

[Wayne Gillispie]

I should have listened to others on this issue. All loops broken off of LH Hinge on the cowl half. One loop broken on RH hinge cowl half. Time to get the .063" and some nut plates out. All other cowl hinges doing fine. I think the airflow through the cowl outlet/louvers is causing this fatigue.

 

[N427EF]

Same here

I had all the loops break off at about 150 hours.
Replaced them with extruded 063 hinge material.
On the RH side the first loop just broke off now at 220 hours.
I think the exhaust pipe may be touching the cowl on starting and shutting down the engine just for a second or two while all the cylinders catch and the engine
Does the classic dog shake.
There is only a half an inch of room in up and down direction on the exhaust pipe
And that momentary rough running on start up or shut down May be all it takes to bang up the cowl to where the hinges break off.
That's my theory and the solution would be to make more room for the exhaust pipe rather than strengthen the hinge section.

 

[Wayne Gillispie]

I have about 1/2-5/8" clearance from exhaust pipe and no signs of contacting.

 

[bob888]

Cowl hinges

Does anybody just skip the hinges and use camlocks for cowling...like my Cessna which has had no cowl attachment problems. I am not yet to the cowl attachment steps on my RV10 project. Maybe there are technical reasons I'm not aware of for using the hinges.

 

[Dbro172]

Does anybody just skip the hinges and use camlocks for cowling...like my Cessna which has had no cowl attachment problems. I am not yet to the cowl attachment steps on my RV10 project. Maybe there are technical reasons I'm not aware of for using the hinges.

That's pretty common too. You can get a varrying degree of cam lock kit, from all in, including the bottoms, to just the tops or sides or bottoms etc.

I used a steel hinge on the bottom in lieu of aluminum, which is pretty common here to it seems

 

[alpinelakespilot2000]

Cam locks on bottom will complicate getting cowl back on as the camlocs have to slide into their receptacles for the side hinges to line up. Makes it more of a two person job. Nut plates don't complicate it.

 

[Bill.Peyton]

6 nut plates on each side attached to .062 flat aluminum bar riveted to the lower firewall lip. #8 screws. 200 hours and going strong
I also re-fabricated the center attachment bracket made from stainless steel. I heard these also break rather quickly

 

[flion]

I've got camlocs on the bottom of my -6A cowl and no problems. On that aircraft the cowl has to be located at the front behind the prop and then scissored up at the rear as I connect the seal to the FAB; the first camlocs that get located are the upper rear and the rest, including the bottom, just fall into line. Looks to me like it will be the same on my -10, and I already have a full set of Milspec camlocs in hand for the job.

 

[N941WR]

Does anybody just skip the hinges and use camlocks for cowling...like my Cessna which has had no cowl attachment problems. I am not yet to the cowl attachment steps on my RV10 project. Maybe there are technical reasons I'm not aware of for using the hinges.

I used camlocks all around my firewall and along the sides. They work great! 500+ hours and no issues.

What I like about using them is I can hang the lower cowl on them by myself and don't need to worry about fitting a hing pin in.

 

[Jesse]

I have seen some hinges break and others perfectly fine after hundreds of hours. I can't explain the difference. I personally hate dealing with that hinge pin and much prefer cam locks on that portion. I prefer the hinge pins for the sides and to hold the top cowl on. If you have a nice tight fit between the baffles and the bottom cowl, you can usually install the bottom alone and it will just sit there once the baffle seal is on top of the inlet air ramps. Then it is easy to put the side pins in and then move to the bottom.

 

[Tim 8-A]

I Made this repair yesterday, after inspection at 180 hours 4 loops (left side) broken off. The right hinge is still secure.

6 nut plates on each side attached to .062 flat aluminum bar riveted to the lower firewall lip. #8 screws. 200 hours and going strong

 

[Tim 8-A]

I Made this repair yesterday, after inspection at 180 hours 4 loops (left side) broken off. The right hinge is still secure.

6 nut plates on each side attached to .062 flat aluminum bar riveted to the lower firewall lip. #8 screws. 200 hours and going strong

 

[Tim 8-A]

I Made this repair yesterday, after inspection at 180 hours 4 loops (left side) broken off. The right hinge is still secure.

6 nut plates on each side attached to .062 flat aluminum bar riveted to the lower firewall lip. #8 screws. 200 hours and going strong

 

[Tim 8-A]

I Made this repair yesterday, after inspection at 180 hours 4 loops (left side) broken off. The right hinge is still secure.

6 nut plates on each side attached to .062 flat aluminum bar riveted to the lower firewall lip. #8 screws. 200 hours and going strong