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EZ-Rocket FAQ

EZ-Rocket:  MAIN  ·  FAQ ·  Multimedia Gallery

The EZ-Rocket with cowlings removed

What is the EZ Rocket?
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 EZ-Rocket includes an external composite fuel tank and an insulated internal aluminum liquid oxygen tank. The modifications were performed at XCOR Aerospace's Mojave, CA shop. Tests were 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, and the Countdown to X-Prize Cup event, in Las Cruces, New Mexico.

Why did you put rocket engines in a Long-EZ?
To show that we can design and build a complete aircraft rocket propulsion system that is safer, simple, cheap, reliable, and above all operable. We are not trying 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, we have gained valuable experience that will make the next generation engines better.

What is that big tank under the airplane?
That is the fuel tank. No propellants are carried in the Long-EZ gas tanks because they are not resistant to alcohol, and because we pressurize the fuel tank more than the strake tanks can handle. The two aluminum liquid oxygen tanks are insulated with styrofoam and occupy the back seat.

Test Pilot Dick Rutan after a successful flight #4

Who are your test pilots?
Dick Rutan was our original test pilot and a design modification consultant for the EZ-Rocket.  As the factory test pilot and major record holder for the Long-EZ, he has over 4,000 hours of flight time in the piston engine version of this airframe.   Dick has flown the EZ-Rocket seventeen times, most notably on its earlier flights.  He has flown it in front of live network television cameras, in front of the crowds at EAA AirVenture Oshkosh, and for its record-breaking flight from Mojave to California City.   (More information about Dick Rutan)

Richard Searfoss has piloted XCOR’s EZ Rocket 8 times; most notably at the Countdown to the X-Prize Cup in Las Cruces, NM, October, 2005.  A two-time Columbia shuttle pilot, Rick is our chief company test pilot and primary pilot for the Rocket Racer, the follow up program to the EZ-Rocket.  Click here for more information about Richard Searfoss.

Mike Melvill flew chase in his Long-EZ for the EZ-Rocket during most of its Mojave flights, and flew the EZ-Rocket itself on flight #8.   This was Mike's first experience with a rocket powered vehicle.   His first words after shutting the engines down were "That was a real kick in the pants!" Several years later, Mike became the first civilian astronaut on June 21, 2004 at the helm of SpaceShipOne.

What is the performance?
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 we will never take the plane to the maximum altitude capability.  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.

A static test at the washrack at the Mojave Spaceport

Does the pilot have to dead-stick land the airplane?
The plane makes a dead-stick landing each time, like a glider.   The engines are restartable in mid-flight.  We have performed numerous restarts and touch-and-goes - the latter of which has never been done in a rocket powered aircraft until now.

Does it make a lot of noise?
Yes. The sound level is 128 dB at 10 meters.  However, during test flights people on the ground have noted that it is quieter than many jet aircraft they have heard.

How many times have you flown?
The EZ-Rocket has flown 26 times. 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 very large crowds of airshow attendees at the EAA AirVenture Air Show in Wisconsin.  Following that success, flights 23 through 24 enthralled the large gathering at The Countdown to the X-Prize Cup Event in New Mexico in 2005.

What are the safety features of this airplane and its rocket propulsion system?

  • 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.

  • 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.

    The EZ-Rocket on its record flight from Mojave to Cal City

  • 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 demonstrated 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 engine 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.

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