The CarterCopter left the ground for the first time on September 22nd, 1998 and flew several times on September 23nd, including several short hops along the runway and one larger hop reaching an altitude of more than 30 feet. The testing ended when a hard landing damaged the aircraft. Because of video footage and telemetry data, the accident has been analyzed and the causes of the accident are well understood. CarterCopters L.L.C. president Jay Carter, Jr. said that the accident demonstrated several of the safety features that were designed into the aircraft. He expected repairs to take a few weeks but that other changes to the aircraft (further described below) would delay further tests for two months.

The test pilot was Don Farrington, holder of all seven FAA flight instructor ratings, a former military and airline pilot, and one of the most experienced autogyro pilots. Jay Carter Jr. was also in the aircraft during all the testing.

The testing, carried out over 4 days during a one month period, began with taxi tests with the rotor autorotating at speeds up to 80 miles per hour. The pilot learned to control the aircraft's pitch by balancing the aircraft on its main wheels while travelling down the runway, with the nose gear off the ground, and with the tail booms (fitted with training wheels) also off the ground. The spindle tilt (rotor disk plane relative to the aircraft) was controlled with the main stick and the collective (pitch of each blade relative to the rotor disk) was controlled with the collective stick. The testing took place on a 5000 foot runway, so the acceleration and braking time limited the time available to test the flight characteristics. Future tests will be done on a longer runway.

The accident occurred during an 80 mile per hour taxi run. When the main stick was pulled back and the collective was increased slightly, the aircraft lifted into the air faster than expected. Due to the time lag caused by the high inertia rotor, the high control forces required for large control movements, the pilot's limited experience with this aircraft, and the impending end of the runway, the pilot overcontrolled the aircraft, resulting in a hard landing.

The high control forces required for large control movements are due to the dogleg design of the rotor tips, which was incorporated in the third set of rotor blades for structural reasons. The next set of blades currently under construction will be straight, like the first and second sets of blades which were successfully tested, and the structural stresses will be reduced using other techniques.

Telemetry data is sent to the ground during all flight testing. The data includes the airspeed, angle of attack, main stick position, collective position, engine RPM, and 78 other flight parameters. Attached is a chart showing these six variables during the mishap run. The horizontal scale is in half second increments.

During the accident, the right wing tip contacted the runway first, followed by the right landing gear. The skewing motion of the impact imparted a side load on the nose gear causing it to fail. The nose pitched down and the tail booms moved up high enough for the rotor to slice through the top of the right fin. The total damage consisted of the nose gear, right wing tip, and the top of the right fin. The rotor was only slightly damaged, but because of the design flaw previously described, a new rotor will be built anyway. The construction of the new rotor blade will be the main cause of delay before further testing.

Several safety features of the CarterCopter helped to minimize the damage. First, the right main landing gear absorbed much of the impact force; its patent-pending design makes it capable of absorbing a 20 foot per second impact with no damage to itself or the aircraft. Second, the design of the tail booms prevented any damage to the propeller and engine. Third, the thrustline of the aircraft is through the vertical CG of the aircraft, and the aircraft has a large horizontal stabilizer, both of which are features that contribute to preventing "bunt-over", a forward snap roll which occurs in some autogyros when the rotor is unloaded. During the CarterCopter mishap, the rotor was unloaded to prevent the aircraft from climbing any higher, which in some autogyros would have been a hazardous maneuver.

The overall test plan is as follows:

1. Learn to fly the aircraft while flying just above the runway.
2. Fly at 2000 feet or more above the airport and expand the flight envelope up to 150 miles per hour (approximately 10 percent load on the rotor) and down to minimum flight speed (about 30 miles per hour). The altitude gives the pilot more time to handle emergencies and gives the ballistic parachute time to deploy if needed.
3. Develop jump takeoff technique.
4. Fly as fast as possible, gradually reducing rotor RPM until 100 RPM is achieved or rotor flapping reaches the maximum safe limit.

The following chart plots some of the flight test data collected during the mishap run. The "Spindle Fore/Aft" and "Spindle Side" show the position of the main control stick. Forward stick is negative and aft stick is positive. Left stick is negative and right stick is positive. The "Fuse to Air" data shows the angle of attack of the aircraft. The aircraft left the ground at 13:33:52, touched down again briefly and then flew until its hard landing at 13:34:00.

CarterCopters L.L.C. is funded by private investors and by a Small Business Innovative Research grant from NASA. The company's business plan is to develop the technology for practical high speed rotary wing flight, prove the technology by breaking records, and then license the technology to kit and certified aircraft manufacturers.

For complete information and pictures of the damage, please see the CarterCopters web site at www.cartercopters.com. Status reports on the flight testing will be posted periodically on the web site.