In the 1970s, the golden age of paper and balsa wood hobby rockets, one of the more interesting models available was the Estes Gyroc, the “whirly bird rocket” with “helicopter recovery.” Unlike most rockets of the time, which relied on an ejection charge and a plastic parachute beneath the nosecone, the Gyroc had a wing and fin design that allowed it to spin down to the ground similar to a whirly bird seed (aka a samara). And given the fact that the rocket weighed less than an ounce, there was little fear of your Gyroc becoming a dreaded “lawn dart,” sans ‘chute.
The supersized MegaGyroc seen here, built by Rich Boyette and a team of fellow Florida rocketeers, which weighs in at around 117 pounds (locked n’ loaded), might be a different story. This 13.5′ tall upsized version of the classic Estes model does use helicopter recovery, like its humbler Estes brethren. It starts its descent in helicopter spin mode, after reaching an apogee of around 3,000, but at around 750′, it deploys a 129 sq. ft. rear-ejection parachute. The “motor can” is also ejected during the flight. Wing span on the MegaGyroc is about 7.5 ft across the flaps.
Rich and the team at least hope it all works this way. They haven’t actually flown this gorgeous beast of a whirlybird yet. The team did build and launch a series of 1/3-scale prototypes last year, flying them on I-motors (and dubbing the prototypes the I-100 and 1-100A). They had both successful and unsuccessful flights on the 1-100 prototypes (i.e. there were some lawn darts), Based on these tests, they made some design changes that are reflected in the full-size MegaGyroc (dubbed the M-100). Below is a video of one of the successful I-100 flights from an on-board camera:
The MegaGyroc will fly on one M1419 main main motor and two K1100 booster motors. The boosters are designed to ignite at the first motion of the rocket (using a deadman switch). The I-series prototypes had plywood skins, but these were too heavy so the team went with fiberglassed foam over a plywood frame spar. The spars extend into the airframe and are clamped together between two plywood plates, which also serve as the storage for the rear-ejection parachutes.
Rich says they’re hoping for the maiden launch at the NEFAR launch, April 9, near Bummell, FL. But, he adds, ” like a NASA launch, no guarantees.” If, say, the wind is much more than 5 mph, or there’s too much cloud cover, the launch attempt will likely be scrubbed.
Will this plus-sized Gyroc crater or drill itself deep into the ground? Will launch event participants be in danger of another dart? Rich says they’ll be firing it downrange of any humans and “cows on the adjacent field will be issued hardhats.”
Building the prototype and the final versions of the MegaGyroc were team efforts. Rich says he did the majority of the design work, the fiberglassing on the two Sonotube airframe tubes, and the aft coupler ring. He also built the altimeter bay and supplied the fiberglass nose cone (which is the only stock airframe component, from Public Missiles). Paul Stutzman constructed the wing cores for the prototype and full-size rockets and fabricated the gas-strut flap actuation mechanisms. Glenn Guarner built the motor can. Bernie Lalime, Kevin Boldt, Mike Bald, Rudi and Rudi Jr Hasselbauer were also involved in the builds of the two rockets.
Maybe we can convince Rich and the team to share some of the launch footage after April 9th. “Only if it doesn’t embarrass me,” he says on Facebook. “It will be twelve seconds of pure terror on the way up,” he continues. “I can think of about six potential epic failure modes for this monstrous perversion of an Estes classic.”
We think it’s an epic success already, just in making the attempt. And in doing it in such style. Besides the beautiful rocket itself, check out the cool rocket trailer that turns into the launch rail!