I too agonized over the suitability of a "morphing" fuel tank so close to the
primary flight controls....and decided on an alloy replacement. Since nobody
was advertising replacement alloy Europa tanks, I decided to build my own=2E For
those of you considering a similar course of action.....here are some of my
observations, both for and against.
If you want to get somebody else to build it fo you it will be expensive. The
complexity of the shape requires many hours of planning and bending, even
though there are no compound curves in any of the panels. The =A3700 you were
quoted Miles, sounds pretty reasonable to me. That leaves one option.....build
it yourself.
Is that possible?
In my opinion...yes.
I, like most of the Europa building fraternity, am a "fist time builder" with
no prior aircraft constructing or metalworking experience, yet by applying the
same techniques of thinking carefully about what you want to do BEFORE you do
it, it really is quite straight forward if somewhat time consuming.....mine set
me back by exactly a year!
Doing it yourself brings the cost down dramatically. I managed to cut all of
the panels out of a 2500mm x 1250mm x 1.2mm sheet of 5251 1/4 hard alloy,
cost..60 GBP (although I bough 2). Here in the UK, this is the nearest I could
get to the 5052 H32 available in the US and supplied by Aircraft Spruce for
fuel tank construction. (A.S in the U.K. quoted over 300 GBP per sheet for
same!)
To this you will have to add the cost of having it welded up by a CAA (in the
UK) approved welder who will also issue a certificate, in my case 250 GBP=2E
I took the opportunity to incorporate a capacitance fuel probe and four solid
state liquid level sensors to give an independent FULL, 2/3, 1/3 and empty
indication. I also have a proper fuel drain, an internal breather, two vertical
baffles and a reliable reserve to give 20 mins flight.
Since my design goal was to get the maximum fuel capacity for no increase in
weight, I now have a tank with a capacity of +/- 22 gallons, an increase of
some 37.5 percent over the standard tank. The finished weight is 6780g compared
to the original tanks 6605g, but since I will not need to install the forward
tank supports, tank laminations or miles of plastic fuel level indicator and
breather, I estimate that the installed weight will be less than the original.
If your design goal was to reduce weight, then an equal capacity tank could be
made far lighter than the original.
Panel projections were designed using "Non-Volatile" CAD techniques (Cardboard
Aided Design). If you chose this method, you might want to budget for a few
extra boxes of Corn Flakes.
Sorry for the "Nuckollian" length of this posting!
If anybody is seriously contemplating a self build tank I would be more than
happy to discuss it further....and anybody living in the south of England is
more than welcome to call in.... contact Roland for the address/number etc.
Happy building
Nigel Graham (147)
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