 Its high-aspect-ratio wing gave it good glider performance at high speed, but yielded too high a sink rate while at thermalling speed.Building new wings for the HP-15 fuselage produced the HP-16.These new 15-meter wings were Schreder's first large foray into an innovative construction method featuring closely spaced PVC foam ribs (usually on 4" centers) bonded to an aluminum wing spar, to which was bonded a thin aluminum skin.