MANASSAS, VA, USA
N162GG
Greenleaf EXEC 162F
The pilot/owner/builder of the homebuilt helicopter departed on a local flight. He completed a traffic pattern, and initiated an approach to the ground. During the final segment of the approach, the pilot found the collective control stick difficult to lower, and the movement restricted. The pilot forced the collective to the full-down position, and the helicopter contacted the ground and rolled over. A 25-pound metal barbell plate was found in the foot well on the copilot's side after the accident. The surface of the plate was lightly coated with rust. Examination of the copilot's seat cushion revealed rust colored transfers on the fabric. The seat pan exhibited circular scratches that measured the same radius as the barbell plate. The collective stick was raised, and the barbell plate was placed so that it was superimposed over the scratches. The collective stick was lowered, it contacted the plate, and approximately the bottom 1/3 of the collective stick travel could not be attained. The pilot explained that on the advice of the kit factory, a 25-pound weight could be added to the co-pilot's side to assist the pilot in achieving a more wings-level vertical ascent to a hover. He said: 'A 25-pound weight in the right seat worked fine. I flew with it all the time. It was secured by the seat belt. On the last flight it was not secured. I just put it on the seat because it was so heavy.'
On April 16, 2000, at 1305 Eastern Daylight Time, a homebuilt Exec 162F helicopter, N162GG, was substantially damaged during a rollover after landing at the Manassas Regional Airport (HEF), Manassas, Virginia. The certificated commercial pilot/builder received a minor injury. Visual meteorological conditions prevailed, and no flight plan was filed for the local personal flight conducted under 14 CFR Part 91. In a written statement, the pilot said: "Traffic pattern on final to 34L at taxiway Alpha. Approached intersection just north of 34L run-up area. Close to touchdown aircraft started a climb and collective was difficult to push down. Aircraft struck ground on left skid, spun 180 degrees and rolled over to right side." In a telephone interview, the pilot stated the purpose of the flight was to practice some hovering and traffic pattern work. He said: "I left the hanger and went to the Runway 16R run-up area to practice pick-ups and sit-downs. I took off Runway 34, flew the traffic pattern, and came around for a normal approach to 34. I was slowing to approximately 30 to 25 knots when I sidestepped to Runway 34L for traffic. I was aiming to land just north of the 34L run-up area. I sidestepped to the left, aiming for the intersection, about 25 feet [above the ground], and the airplane starts climbing." The pilot said he attempted to lower the collective, but that it was "hard to push down." When questioned about the helicopter's performance to that point, the pilot said: "It was vibrating a bit but it was behaving fine. I was at 70 knots on downwind. On approach the collective came up and it was hard to push down. It wasn't impossible, but it was very stiff." Examination of the helicopter by an FAA inspector revealed the vertical collective push/pull tube appeared bent, and that the upper rod end clevis had contacted the upper fiberglass "doghouse" fairing. The helicopter was recovered to a hangar at the Manassas Airport, and examined by a Safety Board Investigator on April 18, 2000. Examination of the upper flight controls and the rotorhead revealed the main rotor mast was bent, and that movement of the controls was restricted. Examination of the vertical collective push/pull tube revealed that both upper and lower rod end bearing clevises were not secure. The lock nuts, bearing clevises, and the push/pull tube could all be rotated with finger pressure. No torque was applied to the lock nuts. Removal of the upper bearing clevis from the collective scissors on the rotorhead revealed the push/pull tube was compressed, and under load. Once the tube was disconnected, the pressure released, the tube straightened, and collective movement was smooth and unrestricted from the cockpit area up through the pylon. The lower end of the push/pull tube was connected to a bellcrank mounted on the collective crosstube below the pilot seats. The crosstube combined collective movement from either side, and transferred it through the bellcrank to the vertical push/pull tube. Examination of the bellcrank revealed an accumulation of metal shavings around the collective crosstube at the bellcrank. The collective crosstube bellcrank mount bolt was not fully seated. The bolt was canted in the hole, and one side of the bolt head rested .165 inches above the mating surface. The lock nut on the other end of the bolt was not fully threaded onto the bolt. The collective crosstube bellcrank was removed and the bolt hole on the top side was elliptical in shape. The collective crosstube contained metal shavings and the bottom side hole was "threaded." Examination of the mount bolt revealed rotational scoring along the entire length of the bolt shank. A 25-pound metal barbell plate was found in the foot well on the copilot's side. The surface of the plate was lightly coated with rust. Examination of the copilot's seat cushion revealed rust colored transfers on the fabric. The seat pan exhibited circular scratches that measured the same radius as the barbell plate. The collective stick was raised, and the barbell plate was placed so that it was superimposed over the scratches. The collective stick was lowered, it contacted the plate, and approximately the bottom 1/3 of the collective stick travel could not be attained. The pilot reported 7,383 hours of total flight experience, 122 hours of which were in rotorcraft. The pilot said he attended the Rotorway factory school approximately 9 to 12 months prior to the accident and had accrued 12.5 hours in make and model. The Hobbs meter in N162GG reflected 4.9 hours of operation. In a subsequent telephone interview, the pilot was questioned about the use of ballast in the helicopter. He explained that weight was added to the exterior of the airframe in different positions depending on the number of occupants. He further explained that on the advice of the Rotorway factory, a 25-pound weight could be added to the co-pilot's side to assist the pilot in achieving a more wings-level vertical ascent to a hover. He said: "A 25-pound weight in the right seat worked fine. I flew with it all the time. It was secured by the seat belt. On the last flight it was not secured. I just put it on the seat because it was so heavy."
Was the pilot' use of an unsecured ballast weight in the cockpit that shifted in flight and blocked the collective control movement.
Source: NTSB Aviation Accident Database
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