HMMM??   Why wouldn't the heavier one need to fly at a slightly faster
speed (best glide speed) and therefore necessarily incur higher drag
since drag is a strong function of speed?  Further, it is necessary to

produce

drag to produce lift, so more wt = more lift = more drag?

You are right, but the heavier body recovers (dissipates?) more potential
energy per 1000 feet of descent which can be equated to more HP than the
lighter body.  The heavier one also descends at a slightly faster rate which
helps to equate to more HP.  Within approximate engineering limits.

Bob Darrah

  Yes !  Of course the heavier aircraft has proportionally more
potential energy to start with !   Thanks.

Bill
Long EZ builder & pilot
mechanical engineer

 
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