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Manufacturer: XCOR Aerospace

Type:  experimental jet-powered version of Long-EZ canard pusher

Program:  Rocket Racing League

Powerplant: 2 x 400 lb. regeneratively cooled rocket engines

Significant date: 2002

The EZ-Rocket is a modified Long-EZ homebuilt aircraft. The aircraft is powered by twin 400 lb. thrust regeneratively cooled rocket engines and fueled by isopropyl alcohol and liquid oxygen. The two engines can be powered on and off on-demand while in flight. The EZ-Rocket can only fly under power for a few minutes at a time, and can only climb to about 10,000 feet on a full fuel load. The EZ-Rocket includes an external composite fuel tank and an insulated internal aluminum liquid oxygen tank. No propellants are carried in the Long-EZ gas tanks because they are not resistant to alcohol, and because the fuel tank gets more pressure than the strake tanks can handle. The two aluminum liquid oxygen tanks are insulated with styrofoam and occupy the back seat.

The modifications were performed at XCOR Aerospace's Mojave, CA shop. Tests are performed at the Mojave Civilian Flight Test Center. The EZ-Rocket has also flown at EAA Oshkosh 2002, the largest airshow in the world, held in Oshkosh, Wisconsin. Rumor has it that when XCOR modified the Long-EZ to become the EZ-Rocket, they approached their local FSDO to relicense N132EZ with an experimental non-certified engine. The story is going around that the FAA guy did not ask what particular engine or even what "type" of engine. A corny story from a company whose rocket engine development team's equally corny motto is "If you can't spill it on your foot, we're not interested in using it in our fuel!"

The purpose of the EZ-Rocket conversion was to show that it was possible to design and build a complete aircraft rocket propulsion system that is safe, simple, cheap, reliable, and above all operable. XCOR insists that they never intended to sell similar aircraft for private use. The choice of the Long-EZ as an airframe was based on its pusher configuration and its good power-off glide capability. By flying and testing, the company gained valuable experience that should make the next generation engines better. None of the operating limitations of a standard Long-EZ are exceeded in this airplane, although a steep climb is needed to keep from exceeding Vne with both engines running.

The first flights of XCOR Aerospace's EZ-Rocket were conducted by Colonel Richard Searfoss a former astronaut and shuttle commander. The EZ-Rocket has flown 15 times to date. The first 13 flights were conducted at our base of operations at the Mojave Civilian Flight Test Center in Mojave, CA. Flights 14 and 15 were performed in front of a very large crowd of airshow attendees at the EAA AirVenture fly-in at Oshkosh, Wisconsin. Dick Rutan was the test pilot on most of the EZ-Rocket's flights, though XCOR chase plane pilot Mike Melvill has also flown the aircraft.. Rutan is under contract with XCOR to fly it and has lots of experience in this type of airplane. His first words after shutting the engines down were "That was a real kick in the pants!" The engines are easily restartable, and Dick Rutan has the choice of extending the glide if he chooses. The engines were recently restarted in mid-flight and the plane has completed touch-and-goes—something that had never been done before in a rocket powered aircraft.

The EZ-Rocket features many safety features, many inherent to the very Long-EZ design:

• The airplane flies just like any other Long-EZ. The pilot does not need to learn to fly the plane at the same time as controlling the rocket propulsion systems. Single engine performance is similar to a Lycoming O-320 with constant speed prop.
• There is an ultraviolet fire sensor in the engine bay that illuminates a light on the instrument panel in the event of a fire. We tested it. It works really well.
• Large bottles of helium can be dumped into the engine bay by pilot command (the guarded "FIRE" switch on the upper panel) for fire suppression. These helium bottles hold several times the inert gas that a fire extinguisher bottle would.
• Each engine has its own dedicated electrical system and controller. They can be independently started and stopped. The plane climbs well on a single engine. (see photo at top of this page)
• Each engine has its own kevlar blast shield.
• Each engine has a chamber pressure gauge that lets the pilot monitor combustion health.
• Each engine has a burn-through sensor connected to a red light on the panel (located just above the chamber pressure gauge).
• The pilot can depressurize either or both propellant tanks in flight. This vents helium outside the airplane.
• The pilot can dump the LOX through a manual valve into the atmosphere. Venting oxygen behind a 200 MPH glider is not hazardous. We've done this during a safe-abort flight.
• Most rocket engine explosions happen because of what is known as a hard start. This happens when main propellants collect in the combustion chamber and are belatedly ignited. We prevent this by interlocking the main valves with an igniter operation sensor. The only time an XCOR engines comes apart is when we put our wrenches on it.
• Main propellant valves are mechanically linked together, preventing incorrect valve timing.
• The pilot has a parachute and the canopy is quick to open.
• If an engine fails to shut down, or a fire is detected, the pilot has a manually operated valve pair that shuts off both propellants to both engines. We've used this feature successfully in a safe-abort flight.

The EZ-Rocket is not the first jet-powered Long-EZ derivative. In 1993, Task Research and Scaled developed the Vantage; a kitbuilder by the name of Greg Richter has been flying a jet-powered version of the Cozy appropriately called the Cozyjet; and a pulse-detonation engine test-bed has also been developed by the U.S. Air Force as the Borealis.

Population: 1 [N132 EZ] (c/n 132)

Specs:
With both engines running (800 lb thrust total) and maximum propellant load, takeoff roll is 500m (1650 ft) for 20 seconds. After pulling up, climb is established at constant airspeed at Vne, or 195 knots. Burnout is after a maximum of two minutes, still at 195 knots indicated, which equals Mach 0.4. The maximum altitude that can be attained is 1.91 miles (10,000 ft). The maximum climb rate is 52 m/sec (10,000 ft/min). It is likely the plane will never be taken to the maximum altitude capability.

Crew/passengers: 1