One of the great things about the BD4 is the never exceed speed of 234 MPH. This means you can use a 350 HP turbo 2 rotor and cruise at 200 MPH. That is far far better than  a  $750.000 brand new Cessna 182.  You can probably get 90 gallons of fuel in it as well. Vans airplanes have a never exceed speed of only 200 MPH. If you install breathing oxygen you can do it at
18,000 feet as well with out going IFR.  The BD4 is a high performance four place kit aircraft and as such
is a real bargain. Easy to build as well.  Paul Lamar


Paul, where does the BD4 get it's good performance specs from?

Steve  Carlisle

No rivets in the wing skin and no struts like a 182.
It is also carefully stressed by a talented engineer.

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The tube spar is a bit heavier than need be towards the outer ends
but it is big labor saving device.

Later versions of the BD 17 tube spar where placed in a big lathe
and the wall thickness was turned down between the ribs.
Probably too expensive.

Then after that they started cutting large holes in the front and
back side of the tube spar to save that weight.

That will also increase the amount of fuel that can be carried.

http://www.bedecorp.com/bd-17l.html

Peter Garrison wrote a good explanation of the tube spar
advantages and disadvantages.

Here is his article in jpg form.

Also a picture of the BD spar with large holes.

Paul Lamar

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