Orange4sky
Well-Known Member
- Joined
- Apr 14, 2020
- Messages
- 93
Hi,
After a lot of deliberation I have decided on wing tip fuel tanks for my 108 experimental build. It only has about 38 gallons stock and I'm putting in an O-540 so it's going to need more fuel. I ike the idea of gravity feed to keep them simple and the fact that they will not alter the C of G. The wings are already extended and squared off for droop tips. I'm thinking of almost full chord, full profile design made of 5052 .050" welded with baffles that extend out from the tank and double as spar tie-ins. Tank construction will be like a stinson tank with bent flanges welded along the outside forming lips. The outermost side of the tank will have to be lap welded on the inside edge to allow for a drillable flange where the tips are screwed on. They will be bolted to the existing spar extensions to allow for both strong attachment and removal. They will hold about 10 gallons each, have cap vents and be gravity feed. I calculated that each linear inch of chord equals about one gallon so they will add about ten inches of length and 4 sq feet of wing area as well.
My questions are mainly structural. Do you think a through spar design like this would be strong enough? I was thinking about screwing them on like a fibreglass tip but was concerned that would not be strong enough. Does anyone have any suggestions or any issues that you can see with this design?
After a lot of deliberation I have decided on wing tip fuel tanks for my 108 experimental build. It only has about 38 gallons stock and I'm putting in an O-540 so it's going to need more fuel. I ike the idea of gravity feed to keep them simple and the fact that they will not alter the C of G. The wings are already extended and squared off for droop tips. I'm thinking of almost full chord, full profile design made of 5052 .050" welded with baffles that extend out from the tank and double as spar tie-ins. Tank construction will be like a stinson tank with bent flanges welded along the outside forming lips. The outermost side of the tank will have to be lap welded on the inside edge to allow for a drillable flange where the tips are screwed on. They will be bolted to the existing spar extensions to allow for both strong attachment and removal. They will hold about 10 gallons each, have cap vents and be gravity feed. I calculated that each linear inch of chord equals about one gallon so they will add about ten inches of length and 4 sq feet of wing area as well.
My questions are mainly structural. Do you think a through spar design like this would be strong enough? I was thinking about screwing them on like a fibreglass tip but was concerned that would not be strong enough. Does anyone have any suggestions or any issues that you can see with this design?