Hangar 9 retract problem fix
Hangar 9 retract problem
Hi,
In another post, it was pointed out the H9 ( Hangar-9 ) retract bellcrank has a problem coming loose, and perhaps even failing. When I started working with the retracts when building my new P-40 Warhawk, I saw what was happenig.
The bellcrank pivots on a screw that is held in place by a piece of plywood at the bottom. The screw goes into a blind nut that can move when the retracts operate. It is a very flimsy mount since it is only anchored at one end and the bellcrank screw wobbles when the retracts are deployed, giving a erratic and sometimes limited movement.
To fix the problem, I added a longer screw, with a additional plywood support, just under the head of the screw. The screw is now supported at the top and bottom. This gives a very positive, secure pivot point for ther bellcrank and makes a very reliable retract movement on the P40 retractable gear.
I did not show a picture of the original parts in place, they turned out blurry, but you will be able to see how the original is done by looking at your own aircraft.
The next few posts will show the pictures of the original parts out of the plane (first picture), the modification parts (second picture) and finally the modification mounted in the plane.
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The first picture ahows the parts that were removed from the wing.
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The second picture shows a picture of the parts that you need to install - there is a longer screw, and a plywood brace.
You will notice I removed the original phillips screw and then added the longer allen screw with the plywood support just under the head of the allen screw. I do not have the dimensions of the plywood, I just it cut out by LAR (Looks About Right) and marked the location for the allen screw hole, and made sure the plywood was wide enough so it can be glued to the rib.
The parts are (in order from top down looking from the underside of the wing):
18 X 3mm Allen Screw
Washer
Plywood support
Washer
Bellcrank
Washer
and they are screwed into place with the allen screw into the existing blind nut already in the wing
Note: if the existing blind nut is loose, make sure you remove it, give it a light coating of epoxy, and put back in place so it will be secure.
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The third picture shows the parts installed in the wing.
With the assembly together, place it in the wing and tighten down the allen screw. Tighten the allen screw so it JUST touches the bellcrank, and the bellcrank can still pivot freely.
Then swing the plywood support so it rests against the rib.
With the plywood support up against the rib, put epoxy on the plywood support and epoxy it to the rib.
Finally, put a drop of epoxy in the allen screw head to stop it from backing out when the retracts are working.
Let me know how it works for you:
I’m retired, so the next step is to start saving my pennies for the Saito 100! I can’t wait to get this thing in the air.
Fly4Fun,
Wayne Miller