When The Skies Were Unfriendly Aviation Designer Resurrects Qn, A Tailless, Flying Dinosaur

March 16, 1986|By Charlie Jean of The Sentinel Staff

Sixty-five million years later, QN is flying again.

He's doing so a bit haltingly at this point because his onboard computer hasn't entirely mastered his distressing total absence of a tail.

QN is a half-scale replica of a flying dinosaur of sorts, a reptile named pterosaur, probably the largest animal that ever took to the air -- a prehistoric flying wing that flapped.

QN is the newest pet, albeit an ugly one, of the Smithsonian Institution's National Air and Space Museum.

It's the museum managers' way of calling attention to the premiere of a new Smithsonian film, On the Wing, which will dramatize flight in all forms, from insects and birds to kites and modern aircraft.

On the Wing will premiere in a few months, maybe in June, featuring QN's feats among its offerings.

To give it a realistic send-off, QN will be launched in Washington on the mall between the Capitol and the Washington Monument, whereupon it will flap and soar among the monuments for a few minutes.

Or at least the museum people sure hope so.

Paleontologist Douglas Lawson started it all in 1972 when he found bone fragments of a wing from a pterosaur in the west Texas badlands. Detective work using bones from small but similar animals helped fill in the picture.

The Smithsonian decided to sponsor a flying mechanical replica to publicize its film, later putting QN on display. Many reptiles flew in prehistoric days, but QN is believed to be the largest. He became extinct along with all the others about 65 million years ago.

To build the replica, the Smithsonian commissioned internationally known aviation designer Paul MacCready, who conceived and built the Gossamer Condor, the first human-powered aircraft to fly a prescribed course, and the Gossamer Albatross, the human-powered craft that crossed the English Channel.

The consensus on what QN really looked like came at a California Institute of Technology symposium in 1984 that pooled the talents of university engineers, NASA engineers, paleontologists, paleobiologists and builders of toy ornithopters, or flapping airplanes.

They concluded that in the main, the original QN was an aerodynamic insult, a 140-pound beast with a 36-foot wingspan, a beak that would make a pelican wince, skin like a bat and nothing in the way of a tail.

QN had a beak but no teeth, indicating it was probably rather mild of manner.

They named the thing Quetzalcoatlus northropi, or QN, after Quetzalcoatl, a feathered serpent god of the Aztecs, and Northrop Aircraft, which pioneered experiments with flying wings.

MacCready, head of AeroVironment of Monrovia, Calif., said the problems of stability and control are proving tough nuts to crack.

''Very little is known about how natural fliers such as birds combine their sensing devices, brains and muscles to fly effectively,'' he said. The challenge of QN is ''especially difficult'' because ''it does not even have a tail to help with stability and control.''

The solution is proving to be an onboard computer that stabilizes QN by moving its head from side to side, extending claws midway out its wings, twisting the wings and swinging them forward and backward.

Battery-powered motors put the flap in QN's horrendous wings. Gyros gauge turning speeds. Sensors figure out the wings' angle to the wind. The computer sorts it all out and tells the wings what to do.

As QN's center of gravity constantly changes, the wings constantly compensate for it.

At first it was planned to make QN a full-size replica of his ancient forebear, but he was reduced to half scale to save money.

The beast has made several test flights in California but still lacks the detailed control that a tail would provide. It has been filmed in flight for inclusion in On the Wing.

MacCready, whose Gossamer Condor hangs in the Smithsonian museum and who is developing QN at a cost of $500,000, is confident all will be ready by June.

''With enough money, anything in aerodynamics is feasible,'' he said.

Walter Boyne, director of the National Air and Space Museum, sees QN as the best of two worlds.

''We hope the project will make a significant contribution to the fields of aerodynamics and paleontology,'' he said.

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