Aviation Accident Summaries

Aviation Accident Summary CHI03FA218

Flint, MI, USA

Aircraft #1

N131MH

Robinson R22-Beta

Analysis

The helicopter sustained substantial damage during a run on landing to the grass infield of the Bishop International Airport (FNT), Flint, Michigan, after the pilot reported he was having difficulties with the helicopter's "vertical pitch" during climbout. The pilot reported that during climbout at about 200-300 feet agl and about 3,000 feet from the approach end of a 7,848 foot runway, the engine was not producing enough lift. The pilot chose to execute a run on landing to the grass infield instead of landing straight ahead on the remaining runway. The ground was rough and the helicopter cartwheeled during the run on landing. The air traffic controller had cleared the pilot to land wherever he needed to land. The helicopter had a total of 56.8 hours since new. The inspection of the airframe, flight controls, and drive train revealed no pre-existing anomalies that would have precluded normal operation of the helicopter. The engine was put on a test stand and an engine run was conducted. The engine met all the parameters specified in the Lycoming "Production Manual Engine Test Log." The pilot reported that he should have landed on the runway, but he landed on the grass because he did not know where the other aircraft was behind him. He reported that he did not want to be a problem, and if he was the only aircraft in the pattern he would have landed on the runway.

Factual Information

HISTORY OF FLIGHT On July 20, 2003, at 0955 eastern daylight time, a Robinson R22-Beta, N131MH, operated by Morton Helicopters LLC, sustained substantial damage during a forced landing after takeoff from the Bishop International Airport (FNT), Flint, Michigan. The commercial pilot received serious injuries. The 14 CFR Part 91 personal flight had been practicing touch and goes at FNT. Visual meteorological conditions prevailed at the time of the accident. No flight plan was filed. The pilot reported that he departed Oakland County International Airport (PTK), Pontiac, Michigan, and flew to FNT to practice touch and go landings. He reported that the helicopter had over a half tank of fuel, and that the distance between PTK and FNT was about 18-22 miles. The air traffic controller (ATC) on duty at FNT and the tower operations supervisor were in the control tower while N131MH was in the traffic pattern conducting touch and goes on runway 18 (7,848 feet by 150 feet, asphalt). They reported the helicopter was conducting touch and goes for about one half hour prior to the accident occurring. They reported the pilot was doing fine in the pattern and that the pilot showed "excellent knowledge of traffic and how to keep out of the way." The tower supervisor reported that the pilot did a "good job of understanding what air traffic needed without asking air traffic control." The ATC controller reported that during the accident takeoff the helicopter's takeoff and climbout appeared to be normal. The helicopter had climbed to about 200 feet above ground level (agl) and was about 3,000 feet from the approach end of runway 18 when the pilot reported having difficulties with "vertical pitch". The ATC controller cleared the helicopter to land wherever he needed to land. After the pilot reported he was having difficulties with the vertical pitch, the helicopter veered to the right side of the runway. The ATC controller reported the helicopter had "lots of speed going down" and then the nose of the helicopter came up and the helicopter "floated" before he lost sight of it. The ATC supervisor reported the helicopter was directly over the runway and at about 200 feet agl when the pilot reported having difficulty. The helicopter veered off to the right, pitched down, and picked up speed. The helicopter "straightened out" and then went out of sight beyond the radar antenna. On July 22, 2003, between 1400 and 1600, the pilot was interviewed in his hospital room. The pilot reported that he had conducted 5-6 touch and goes in the FNT pattern prior to the accident. He reported that during the accident the helicopter went through translational lift and he climbed a little more vertical than normal, but it wasn't a high performance takeoff. He reported that while approaching 300 agl, the engine was not producing enough lift and he reported to ATC that he had a problem with "vertical pitch." He reported that he decided to land on the grass instead of the runway because there was another airplane that was approaching the airport for landing on runway 18. He turned to the left and tried to get forward airspeed by lowering the nose. He reported that the engine was still operating but he wasn't getting the lift he expected. He reported the ground was coming up fast and he attempted to do a run on landing. PERSONNEL INFORMATION The pilot held commercial pilot and flight instructor certificates with a helicopter rating, and a private pilot certificate with a single engine airplane rating. He held a Second Class medical certificate that was issued on January 3, 2003. He had a total of about 4,400 hours of flight time, of which 4,030 hours were in helicopters and 370 hours were in single engine airplanes. He had about 3,500 flight hours in a Robinson R-22 of which 3,400 hours were logged as a flight instructor. AIRCRAFT INFORMATION The helicopter was a single engine Robinson R22 Beta, serial number 3449. The two seat helicopter had a maximum gross weight of 1,370 pounds. The engine was a 180 horsepower Lycoming O-360-J2A engine. The helicopter had a total of 56.8 hours since new. METEOROLOGICAL INFORMATION At 0953, weather conditions reported at FNT were: Winds 220 degrees at 6 knots, visibility 10 statute miles, scattered clouds at 11,000 feet, temperature 22 degrees C, dew point 14 degrees C, and altimeter 29.94 inches of mercury. WRECKAGE AND IMPACT INFORMATION The helicopter wreckage was located on the grass infield of the FNT airport south of the Air Surveillance Radar (ASR) radar antenna. The wreckage path was oriented on a southwesterly heading and it was approximately 150 feet in length. The terrain was flat but the ground was rough due to ridges in the field. The fuselage was partially inverted and resting on it right side. The tail boom was jackknifed to the right side of the fuselage. The "red" main rotor blade was intact and remained attached to the rotor head. It exhibited aftward and upward bending, and trailing edge buckling. The "blue" main rotor blade was fractured 77 inches and 119 inches from the teeter bolt. It exhibited downward bending and trailing edge buckling. The tail rotor and empennage had separated from the rest of the tail boom. One tail rotor blade was buckled and twisted aft at the end of the root fitting. The other tail rotor blade was fractured approximately 8 inches from the center of the tail rotor output shaft. The landing gear cross tubes and landing gear skids had separated from the fuselage. Both fuel caps were found secure and fuel was drained from the aircraft at the accident site. The gascolator screen was clean and free of contaminants. The inspection of the cabin revealed that the collective was in the full up position. The throttle rotated and the over travel spring functioned. The mixture was in the full rich position. The carburetor heat control was extended so that the top of the control was 2.5 inches from the panel. The carburetor heat slider was found in a position approximately one-half way between full cold and full hot. The inspection of the drive train revealed that the drive belts and the belt tension actuator were intact. The sprague clutch locked and free-wheeled properly. The forward flex coupling appeared undamaged. The main rotor gearbox rotated freely for at least one full revolution. The intermediate flex coupling was intact but pulled aft. The tail rotor driveshaft bearing was free to rotate. The tail rotor drive shaft was separated approximately 9 inches from the intermediate flex coupling and at the aft end of the 3rd tailcone bay. The rear flex coupling was intact. The tail rotor gearbox rotated freely for at least one revolution. The tail rotor pitch change slider bearing was free to rotate. The tail rotor hub was intact. The inspection of the flight control system revealed continuity. The fracture surfaces of the control tubes that were damaged all revealed fractures consistent with overload failures. The inspection of the flight controls revealed no pre-existing anomalies that would have precluded normal operation of the helicopter. The inspection of the engine revealed that the alternator exhibited circumferential scoring immediately forward of the alternator cooling fan. The engine cooling fan exhibited circumferential scoring on its outer rim. There was black material transfer on the upper steel tube frame adjacent to the upper belt pulley. The engine was free to rotate. The engine was shipped to Textron Lycoming for further inspection. The RPM governor control box was shipped to Robinson Helicopters for further inspection. TESTS AND RESEARCH On September 3, 2003, the engine was inspected at Textron Lycoming, Williamsport, Pennsylvania. The engine was put on a test stand and an engine run was conducted. The engine met all the parameters specified in the Lycoming "Production Manual Engine Test Log." After the engine run was completed, the Textron Lycoming Mandatory Service Bulletin No. 388B was performed in order to determine exhaust valve and guide condition. The procedures for the service bulletin were complied with and all exhaust valves and guides were found within the tolerances specified in the service bulletin. On October 15, 2003, the R-22 governor control box was inspected at the Robinson Helicopter Company, Torrance, California. The inspection of the governor control box revealed that it met all specifications of the governor controller and functional tests. ADDITIONAL INFORMATION During an interview, the pilot reported that he should have landed on the runway, but he landed on the grass because he did not know where the other aircraft was behind him. He reported that he did not want to be a problem, and if he had been the only aircraft in the pattern he would have landed on the runway. Parties to the investigation included the FAA, Textron Lycoming, and the Robinson Helicopter Company. The aircraft wreckage was released to Pathfinder Insurance, 2901 Airport Dr., Torrance, California.

Probable Cause and Findings

The loss of engine power for undetermined reasons, and the pilot's inadequate decision to land on an unsuitable area.

 

Source: NTSB Aviation Accident Database

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