The International Cessna^® 170 Association

I just pulled my fuel tanks in preparation for reskining the wings. Getting the screws out that hold the fuel tank straps closed was nearly impossible. I ended up cutting the screws out. The problem was the nuts on the screws were nearly inaccessible in the tight space and they were also rusted in place.
When I checked the Cessna 170A parts catalog, it doesn't show any nuts on those screws. So does anyone know what is supposed to hold the screw on those straps? I wonder if there is supposed to be some sort of nutplate or captive nut permenantly attached to the strap. I need to find the right way or at least a better way before I put this all back together.
Thanks,
Keith Norton

Kieth, the 170A IPC shows the screws and nuts as item 21 which are AN520-10R26 screws and AN365-1032 nuts. The straps should have had those hardware items located on top of the tank in full view and easily accessible. See pg. 12, Fig 7, item 21 of the IPC.

Thanks George. I missed the nut in the parts manual when I looked before.
My tank straps meet between the tank and the outboard wing rib. That makes them very difficult to install remove. I will rework them to meet on top before I reinstall the tanks.
Thanks again,
Keith

Keith & George,

The fuel tank strap harware on my 1956 Cessna is also located in the narrow space between the fuel tank and outboard rib. That's not the way it is shown in the Illustrated Parts Manual, Fig.2-41. As George mentioned, the Parts Manual shows it mounted on top of the gas tank. However, on my plane, the hardware would rub the fuel tank cover assembly, where the cover assembly pad (Fig.2-43 & 44) rests on the strap assembly (Fig.3-22 & 23).

Is the location shown for the hardware wrong in Fig. 2? Since Keith and I have both opened up the fuel tank bay and can see the parts, I question the accuracy of the Parts Manual. Does anyone else have actual hands on experience with this.

Jim
N3415D
SN 26958

I just removed and replaced my tanks. The straps are on the side also, and the nuts are very hard to get at. I went to Ace hardware and bought a cheap 3/8" wrench. Put it in a vice, heat it with a torch (propane works fine) and bend it 90 degrees just above the box end. You should be able to get the nuts in and out with this tool. Put some aluminum tape on the bottom of the box end to catch the nut after the nut has passed the last threads, and to hold it in place to get the nut started.
jc

From a credible source, I'm told that the IPC was developed from engineering drawings in consultation with the production department. There were some instances of assembly-line expediencies that were subsequently developed but not implemented in the IPC if no actual parts differences were entailed or if subsequent Service Letters altered the assembly to solve service difficulty reports. In this case, the answer is unknown, but it's possible that the chafeing of the screws/straps caused a change to the assembly line procedure that was deemed not worthy of IPC revision,...or that the revision was not incorporated in the most common versions of the IPC. (The Univair copy of the IPC had it's last revision in 1971.)