Unusual fuel tank location Draco Wilga

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Riggerrob

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A much-modified PZL Wilga STOL airplane showed at Oshkosh 2018 with unusual fuel tanks.
The modifier installed extra fuel tanks in the undercarriage legs! He started with a Wilga 2000 that already has wide-chord main landing gear fairings, then he installed a Pratt & Whitney PT6a-28 turboprop engine producing 680 horsepower. To handle the extra fuel consumption, he added fuel tanks inside the main undercarriage fairings.
At least one other Wilga 105 has been converted with a (Walter?) turboprop in Eastern Europe, but it retains the original - narrow chord - undercarriage fairings.

1 - header tank between firewall and instrument panel
2 - upper wing centre section (especially biplanes)
3 - inside wings
4 - tip tanks (Pazmany)
5 - fuselage belly
6 - behind cockpit
7 - drop tanks
8 - wing strakes (especially Rutan)
9 - horizontal stabilizer (airliners)
10 - vertical stabilizer (airliners)
11 - baggage compartment (RV-12)
12 - cargo compartment (ferry tanks)

Can anyone think of any other place to install fuel tanks?
 

Victor Bravo

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The Wilgs is likely hellaciously overbuilt (designed to land across the furrows of a Soviet-era potato field). So a fuselage centerline "slipper tank" would likely be within the structural capability of the airplane.
 

Mad MAC

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I seem to recall that the Wilga has quite close coupled wing pickups (fore and aft direction) and one of them is subject to an AD, so that could have dictated the fuel location.

There have been several attempts at towed flying fuel tanks.
Overwing scab type slipper tanks (FW190, mid span on wing)
Fuel drums on seats (ferry fuel tank install on small GA)
Bag tanks on cabin floors (ferry fuel tank install)
Under floor fuel tanks (helicopters)
 

Tiger Tim

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To handle the extra fuel consumption, he added fuel tanks inside the main undercarriage fairings.
There's a video where he says the gear leg 'tanks' are more like really low sumps to prevent fuel pick-up unporting in aggressive slips. His left and right wing tanks are connected by high-flow lines to the gear legs, and the engine only draws fuel from the leg tanks.
 

Deuelly

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One of the big reasons for the gear leg fuel tanks is so there's still fuel at the pick up when he does is 45゚ climb outs.
 

Voidhawk9

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I see the point of Draco's gear tanks. But I can imagine a very bad day should they ever be sheared off in an accident!
 

Victor Bravo

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I'll buy into the 45 degree fuel pickup idea rather than the increased capacity idea. I'm pretty sure that monster will sustain flight in a 45 degree deck angle for a while.
 

Chilton

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The Short-Mayo composite used the floats as fuel tanks, I have heard of the upper or lower cowlings being used as oil tanks, not sure about fuel though!

I think some brave individuals have made seat fuel tanks but not sure I would like that.
 

bmcj

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The Howard DGA also carries fuel in three tanks under the floor:



Note the three fuel tank fillers.
Yep. I used to fuel mine (150 gallons IIRC) without batting an eyelash 35 years ago, but at today’s fuel prices, I’d probably risk a coronary and lose my medical if I had to pay to fuel up.
 
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