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From what i've seen delta wings are more appropriate to supersonic designs, and have poor lift/drag ratios at subsonic speeds. The Starship had a cruise speed of 300 kn, so what was the reasoning behind the wing design?

I know that the engine on the back/pusher configuration puts the CoG further back, so you would want to put the wings behind, but the Piaggio Avanti does the same with conventional wings.

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    $\begingroup$ On a side note, I like the Starship, and if anyone ever comes to see Jack Daniels in Tennessee, the closest airport, (KTHA) has a Beechcraft museum on the field with one of these. During their slow season, my brother and I went there, and the museum staff let us walk up inside of it. The museum is called "The Staggerwing Museum." $\endgroup$
    – Ryan Mortensen
    Commented May 8, 2016 at 20:48
  • $\begingroup$ Why do you think the Starship has a delta wing? $\endgroup$
    – jamesqf
    Commented Mar 5, 2018 at 20:09
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    $\begingroup$ That’s not a delta wing. $\endgroup$
    – Romeo_4808N
    Commented Mar 6, 2018 at 20:46

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Because it was something of a Burt Rutan trademark since his early days. His first designs, the VariViggen and VariEze, had such a wing already, and apparently he saw no reason to optimize the wing of the Starship.

Rutan VariEze in flight

Rutan VariEze in flight (picture source)

The only true innovation was a variable geometry canard, which he even patented. Being only 85% scale, the performance of the Starship prototype was formidable, but once the real production aircraft had been designed with full compliance to airworthiness regulations, the Beech Starship turned out to be less impressive. The additional wetted surface produced more friction drag. Piaggio's design is clearly superior.

By the way, the idea behind the variable geometry canard was sound: In the landing configuration it would balance the additional lift from the fowler flaps on the wing. But the whole mechanism cost more in weight than the reduction in drag during cruise could save.

Drawing from US Patent 4641800

Drawing from US Patent 4641800.

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  • $\begingroup$ Thanks. So there's no advantage compared to the Piaggio. But for smaller planes, like the VariEze, is there a good reason for the delta wing, or is it just a quirk? $\endgroup$
    – Southbob
    Commented May 10, 2016 at 13:00
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    $\begingroup$ @Anonymous: The delta would help at high angle of attack, but you want the wing of a canard to stall first. So in principle such a wing has its advantages, but is the wrong choice for a canard configuration. Besides, the sweep makes it less effective and only helps to give the fins some more lever arm. But the cost for this lever arm is hard to justify. So, yes, it's more a quirk. $\endgroup$
    – Peter Kämpf
    Commented May 10, 2016 at 13:42
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It's necessary to put the fuel tanks close to the cg of the aircraft so fuel burn doesn't significantly change the cg. This was done as a Delta in front of the main wing.

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