LANSING, IL, USA
N4088X
HUDSON AVENGER
The gyrocopter impacted terrain following an uncontrolled descent. The owner/builder of the gyrocopter was reported by a witness to have been adjusting the weight and balance to improve the handling qualities of the gycrocopter through the addition of 25 lbs of ballast in the forward nose section of the gyrocopter. A witness reported '...hang tests [the pilot] and a 'passenger' of approximately 250 lbs. hung 6.8 degrees nose down...' He added that '...Most gyroplanes can be flown with a C of G range of 0 to 6 degrees nose down...'
HISTORY OF FLIGHT On August 15, 1999, at 1438 central daylight time, a Hudson Avenger Gyrocopter, N4088X, owned and piloted by a student pilot, was destroyed on impact with a bean field approximately 1,000 feet south of the Lansing Municipal Airport, Lansing, Illinois. Visual meteorological conditions prevailed at the time of the accident. The 14 CFR Part 91 personal flight was not operating on a flight plan. The student pilot and private pilot rated passenger sustained fatal injuries. The local flight was originating at the time of the accident. The vice president of the Greater Midwest Rotorcraft Club reported the following, "On ... August 14th ... [the pilot] requested my assistance at his hanger across from mine at Lansing. [The pilot] has always had an increasing back stick force when flying at higher airspeeds with his gyro. Last year during a 100 mile cross-country flight, [the pilot] complained that the tiresome force was nearly unbearable. [The pilot] flew with a rather large flight instructor once and commented that it was the only time the gyro felt comfortable. Most gyroplanes have a "trim" spring that applies a bias to counteract the "offset gimble" design of the rotorhead; it provides an artificial stability that helicopters lack. [The pilot's] trim springs were located behind the mast and, if used would apply assisted back stick forces. As such they were adjusted slack and inoperative. At a recent rotorcraft convention, an experienced gyro pilot with a two-place gyro suggested [the pilot] try adding ballast when flying solo. He offered that during his airshow performances 30 lbs. of ballast really made a difference. [The pilot] and I performed a hang test to measure the gyro's relative angle when hung from it's rotorhead... The 25 lbs of lead shot placed in the nose caused the nose down angle to increase 2.5 degrees..." The vice president further added, "Most gyroplanes can be flown within a C of G range of 0 to 6 degrees nose down. On the Saturday hang tests [the pilot] and a "passenger" of approximately 250 lbs. hung 6.8 degrees nose down..." The vice president also reported, "...I observed a Marchetti Avenger gyroplane, built from plans by [the pilot], taxi by my golf cart on the way out to runway 27 at the Lansing Municipal Airport in Lansing, IL. ...I returned the golf cart to the FBO... As I walked past the open hangar door I observed [the pilot's] gyroplane flying in a westerly direction, directly south of my vantage point, about 300 yards away at an altitude of 200 to 300 feet. (Estimated) The gyroplane appeared to be functioning normally, flying straight and level at an estimated 40-45 mph when I clearly observed the nose rise abruptly three times. This was NOT a phugoid oscillation, but a rocking motion with little or no altitude excursions. The third pitch up lasted longer [than] the previous two. All occurred within one to two seconds. During the pitch ups the aircraft speed slowed considerably. At this time the nose of the gyroplane started to slowly pitch downward. The rotorblades slowed remarkably fast (consistent with reversed airflow and negative "G"s.) When the gyroplane reached an approximate 45 degree nose down attitude, the rotorblades had slowed to an approximate 100 RPM... As the gyro approached 90 degrees (vertical) the rotors were flapping violently and struck the airframe with a loud "Bang". Pieces of rudder and possibly the propeller fell from the aircraft. The aircraft was now falling inverted. At an estimated altitude of 20-50 feet I lost sight of the gyro behind parked aircraft. I then heard the sound of the aircraft impact." PERSONNEL INFORMATION The student pilot and builder of N4088X was 54 years old and was seated in the right seat of the gyrocopter. He held a third class airman medical and student pilot certificate issued June 6, 1999 with a limitation, "must possess corrective lens for near vision". At the time of application for his third class airman medical, he reported a total flight time of 180 hours of which 5 hours were in the past 6 months. The private rated pilot was 44 years old and occupied the left seat of the gyrocopter. He held a private pilot certificate with q gyroplane rating. He received a third class medical on September 22, 1996 with a limitation, "holder shall possess corrective glasses for near vision". At the time of application for his third class airman medical, he reported a total flight time of 500 hours. WRECKAGE AND IMPACT INFORMATION The main wreckage was laying on its right side oriented on a southerly heading in level bean field. The main rotor, engine and its propeller were found attached to the airframe. Each main rotor blade was deformed approximately 70 degrees upwards at the accident site. Pieces of the vertical stabilizer(s) were located along a 300 foot path north of the main wreckage. Flight control and engine control continuity to the cockpit was established. The propeller remained attached to the engine and was rotated by hand. Upon rotation, air was expelled from each cylinder and engine continuity was established. Both magnetos were rotated and a spark from each lead was noted. A bag labeled, "25lbs No. 7 1/2 chilled lead shot" was found in the froward most section of the gyrocopter nose section. MEDICAL AND PATHOLOGICAL INFORMATION FAA toxicological test results for both occupants were negative for all substances tested. An autopsy of the student rated pilot was conducted by the Office of the Medical Examiner, County of Cook, Illinois, on August 16, 1999. ADDITIONAL INFORMATION The wreckage was released to the Vice President of the Greater Midwest Rotorcraft Club.
the weight and balance exceeded by the owner/builder. The inadequate preflight planning/preparation by the owner/builder.
Source: NTSB Aviation Accident Database
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