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HawkinSF

Member
Took over an existing project, found late in the game that the fuel tanks are not set up for aerobatic flight. Do I a) Tear the wings apart and rebuild the wings with fuel pick ups and the correct fuel guage sending units, or b) Install a header tank (one gallon would do it), or c) Does anyone have an idea?
 
remove the tank

The easier route would definitely be to just remove a tank, install a flop tube and the few brackets needed, and close 'er back up. It really shouldn't be too bad.

Good luck.
 
Just install the flop tubes, I did it on a project I bought with standard pickups. It isn't such a bad job, way easier than coming up with another tank.
 
Agreed...this is what you have to do to add flop tubes in qb tanks anyway...it's not that hard.

Frank
 
My partner (IA A&P) thinks it will take a hundred hours to dismantle both tanks, install the flop tubes, and change the sending units for the gas guages. That's a bundle. Off the mark?
 
HawkinSF said:
My partner (IA A&P) thinks it will take a hundred hours to dismantle both tanks, install the flop tubes, and change the sending units for the gas guages. That's a bundle. Off the mark?
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That's probably pessimistic.

At worst, you only need to do one tank anyway, and use that tank for inverted flight.
 
Flop Tube

Took me all of 2 nights after work to install flop tube and move sender to second bay of a QB tank. After all the paint blisters I got I should of rebuilt both tanks properly. If they are QB tanks tear into and repair before you paint.YMMV.
 
found late in the game that the fuel tanks are not set up for aerobatic flight
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What sort of aerobatics do you want to do?

IMHO, Flop Tube(s) are unnecessary, unless you want to do sustained inverted flight... which in turn requires a full inverted Oil system.

Flight tested an RV-8 recently with 1 Flop Tube and full Inverted Oil. 5000', 75%, and happily did 1min+ inverted on the Flop Tube tank. Repeated on non-Flop Tube Tank, ran for 23s before faltering.

Unless you really want to fly inverted for 15s+ at a time, and have the other systems to cope with it, I would not worry about Flop Tube(s) :)

Andy
RV-8 G-HILZ
 
Thanks all, makes a lot more sense now. We have the tang half way out, and will convert the left tank only. We do want to do extended inverted flight (I fly an Extra 300 and Pitts S2a now), and will install full inverted oil system. Thanks to everyone for straightening me out!!!
 
We do want to do extended inverted flight (I fly an Extra 300 and Pitts S2a now), and will install full inverted oil system.
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Sounds like you might then also want to run the breather to the tail :eek:

Andy
 
FWIW...

...the RV-6, -7, -8 airfoil does pretty good inverted flight. There's a video of a South American -6 doing extended inverted flight at very low altitudes but I can't find it right now, with not an excessive angle of attack either.

Good luck, and kindly post some video here of your extended inverted flight.

Regards,
 
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