Y

yankee-flyer

Well Known Member
For those with a flying airplane, I found an easy way to drill all the new holes for the gear SB without removing or risking damage to damage the tank. There's plenty of room to slide a piece of .040 aluminum between the side of the fuselage and the tank-- make sure it goes all the way to the floor. Then I put a drill stop on the #30 drill and had no problems. In most cases the bit never touched the sheet and when it did the sheet moved back so the bit never even started to penetrated that, much less the tank.

Wayne 120241
 
I did the SB - actually "me" and "Tony T" on N737G - we never pulled the fuel tank. A drill stop is all you need. The drill never comes even close to the tank. I'm a'betting we vac'd and mag'd out 98% of the debris.

I'd recommend leaving the tank IN.

Bob Bogash
N737G
 
I'm doing my first annual and installing the MLG mod. My tank fittings and seams are dry as a bone, and there is no sealant in the gascolator. I'm leaving the tank in.
 
If you take your tank out, split the rear bulkhead and cover plates under it, see the modifications sticky thread. If you haven't done that, how to you do an annual without taking out the tank to look in the tail?
 
Did that

Did the floor/bulkhead mod per the forum 2 years ago at the first annual. That's why I did NOT want to remove the tank again

Wayne
 
I took a different approach and added four 4" diameter inspection holes on the bottom of the fuselage and one on the starboard side near the tail. I can remove the counter balance, inspect the roll servo and replace the elevator cable wear block without removing the luggage compartment bulkhead.

I also put an inspection port under each control stick mount.
 
I don't trust those hex-key drill stops. I chucked the bit and cut a short piece of leftover stiff plastic tubing just shorter than the bit. I restricted the bit penetration to about 1/4 inch then the skin hits the tubing (which I could hold!). Foolproof. I used it for both the rivet drillout and the new holes. I just drilled all those holes today. A piece of safety wire showed a one inch minimum clearance from any new hole to the tank- at least on my plane. Now to get the swarf out from under the tank - any ideas?
 
Last edited:
I did something similar to what Bill did, but I used a piece of left over aluminum fuel line around the bit to limit penetration. I didn't scratch the skin, but Bill's idea of plastic tube is probably a better approach.
 
You must log in or register to reply here.