Vid title: Bad hang glider loop

Illustrations and related contemporary links. Commentary is welcome. Send to Editor@UpperWindpower.com

Lessons learned since 1976? Readers are invited to comment on Ray Hook's notes of 1976.   An extensive interview from 1976 will be republished in the April issue of Lift; that interview was also in the HGW V3N32 that was published on May 31, 1976.
Thanks to Seedwings  for the copy of that issue for this lookin- back adventure.

Vids of contemporary loops:

• First loop in a hang glider. Pilot Rudy Kishazy
   
• loop failure hang gliding
   
• Looping Hang Glider Rafael Watson
   
• Hang Gliding Bill Heaner Extreme Acro

Larry Newman had made a hang glider flight off Makapuu.
http://tinyurl.com/1972to1978HawaiiNotes8888Lift

From Ray Hook, the designer of the Wind Gypsy, perhaps the first in the world to perform loops in rogallo wing hangliders, improver of flying techniques and equipment, and owner of Dove Hang Gliders of Hawaii:

Dear HGw,
       The loop is one of the simplest maneuvers ... also one of the most dangerous. Most hang gliders, if stalled on top will stabilize inverted. One must have high speed in order to remain positive on top. ((So the sail is inflated in the same way one has it in normal glide.)) When inverted, falling trough is one of the easer ways of getting killed; this can happen without a "catch bar." Speed, pitch control, and inverted pull out are the keys to good loops.

The catch bar is a piece of one inch diameter tubing mounted across the back flying wires thee feet behind the control bar. This prevents the fall through on top of loops should inverted stall occur.

The first loops were done over a year ago in an 18' leading edge, 16' keel length homebuilt that had three feet of hollow and had a flat billow.  ((Hollow is the amount that the sail trailing edge fails to meet the imaginary line between the leading edge outside tip and the aft point of the sail at the keel.))  The sail hollow cut gave better pitch control.

Since those firs loops I have also looped a Brock 16' LE, 15' Keel, and a California Gliders' hang glider that had one foot truncated tips and 16' leading edges.  Further, I now have a design that will not stop upside down; it has an L/D of 11 to 1; it folds into bag fit, is easier to manufacture than standard trunc' ((truncated wing tip hangliders)) ships.  This design will eliminate the problems of tucking or getting spit out of thermals.

As to stalling out on top, I have the catch bar. But I also follow this rule: Always roll out of a stalled situation as pitch can easily overload the glider.

There are several people here doing 3/4 loops, contrary to Roy Haggard who came over to try one in the worst possible machine, forgot to hook in, fell out, broke his experimental hang glider, sold it to an inexperience pilot and left.

Ray Hook
<address in Hawaii was published>

P.S. IF ENOUGH INTEREST IS SHOWN, I WILL SEND YOU THE DESIGN TO PRINT IN HANG GLIDER WEEKLY OF A BETTER MACHINE.