The Cessna 120-140 Association Forum

I am restoring N72622 (1946 C120 #9798) and trying to decide how to get all the collected grime and dirt out from under the floorboards and install a new battery cable. The only access seems to be these little holes.
Does anyone have a better idea for how to get in there?

Wellllll............... I feel your pain. I was in the same place years ago.

I determined it was easiest to just un-rivet the floor boards, and that makes it much better access.
Why..........Why!? Cessna decided to run the battery cable under the pilots floor board we'll never know.

The floor boards are suprising "easier" to un-rivet then replace.

Best advice I can give, It's almost impossible to accomplish your two tasks with the floorboards in place.

I agree with Victor. There's really no other way to do a good cleaning.

I think I recall using a ball peen hammer as a bucking bar down inside the gear box...

could install a inspection cover

VIP620 wrote: ↑Fri Sep 05, 2025 8:54 am could install a inspection cover

Now that you mention it, I did that, after the fact. I wanted to make sure I dealt with everything the mouse left behind.

Are there design guidelines for inspection covers? I can't find anything about this in AC 43.13

I got those floorboards out and there was SO MUCH gunk under them.

chriscrewdson wrote: ↑Sun Sep 07, 2025 10:00 pm I got those floorboards out and there was SO MUCH gunk under them.

That............!! is an impressive amount of "Gunk". You win the award.....and not the one you probably wanted to win!

As far as inspection panels, just match one of the other ones you have on the aircraft, like on top of the gear box, left and right of the trim wheel.