Aviation Accident Summaries

Aviation Accident Summary CHI97FA025

GUTHERIE, IL, USA

Aircraft #1

N86214

ENSTROM F28F

Analysis

Eye witnesses observed the helicopter lift off on its left skid while moving forward a short distance. After stopping its forward motion the helicopter began moving backwards and slowly rolling into a steep left bank and gaining altitude. After the helicopter travelled about 75 feet and climbed to about 25 feet above the ground it moved to its left. As it passed over a farm truck, its rotor blades struck the roof. Shortly afterwards the helicopter rolled inverted and collided with the ground. Witnesses reported the wind at between 15 and 20 miles per hour, blowing on the helicopter's right rear side. The pilot's former instructor said he had not taught him to '...translate rearward.' He said he had told the pilot it was not safe to takeoff with a quartering tailwind.

Factual Information

HISTORY OF FLIGHT On November 11, 1997, at 1100 central standard time (cst), an Enstrom F28F, N86214, piloted by a private pilot, was destroyed during a collision with a farm truck and the ground while maneuvering. The personal 14 CFR Part 91 flight was not operating on a flight plan. Visual meteorological conditions prevailed at the time of the accident. The pilot and two passengers were fatally injured. The flight departed a cut corn field near Gutherie, Illinois, at 1058 cst. According to two eye-witnesses, the helicopter sat near the southwest corner of a large building with its engine idling. They said the helicopter began lifting off on its left skid while moving forward a short distance. The helicopter stopped its forward motion, and began moving backward, roughly parallelling the building's west wall. During the northerly ground track, the helicopter's altitude increased to about 25 feet. They said the bank angle continued to steepen as the helicopter moved backwards. After the helicopter had moved about 75 feet over the ground, its ground track changed to an easterly direction. One witness said the "...prop was straight up and down..." as it passed the northeast corner of the building. During this phase of flight the helicopter's rotor blade struck a farm truck's (truck) roof. The truck was near the northeast corner of the building. After its rotor blade struck the truck, the helicopter rolled inverted and collided with the ground. Witnesses reported the wind was coming from the northwest at between 10 to 20 miles per hour. OTHER DAMAGE The steel roof of the truck's driver side had a cut along its left edge measuring about 30 inches. This cut began about 6 inches aft of the roof's front and ended about 8 inches from the back of the roof. The steel roof was 1/8-inch thick. PERSONNEL INFORMATION The pilot obtained his single-engine airplane private pilot certificate on March 25, 1988. The pilot began receiving helicopter dual instruction on March 3, 1996, after having flown 973.9 hours. Before this date he had received .7 hour of dual instructionin what his logbook stated was an "Intro to helio..." during September 4, 1995. On March 17, 1996, the pilot had the rotorcraft, helicopter, rating added to his private pilot certificate upon completion of a flight test. His logbook showed he had accumulated 71.5 hours total time in helicopters when he obtained this rating. The logbook showed 29.7 hours of this time was "...dual received... ." The logbook showed no additioanl dual instructional flights after his rating flight test. The pilot's logbook showed he had accumulated a total time of 1,157.4 hours total time by September 12, 1996. Of this time, 162.6 hours were in helicopters. Flight time or recency of experience records beyond this date were not found. WRECKAGE AND IMPACT INFORMATION N86214 collided with the ground about 90 feet from the farm truck with the cut roof. This point of impact was on a magnetic heading of 120 from the truck. Ground scars and scuff marks about 30 feet long continued eastward to the helicopter's final resting position. The helicopter was resting on its left side on a magnetic heading of about 070 degrees. Its tailcone had separated from the fuselage and was angled upward about 30 degrees relative to what was the top of N86214's fuselage. The main rotor head and blades had separated from the rotor mast and were laying under the separated tailcone. The tail rotor and gear box had separated from the aft-most section of the tailcone and was about 40 feet southwest of N86214's fuselage. The horizontal stailizer and tail skid was about 160 feet southwest of N86214's fuselage. N86214's cockpit area was crushed downward about 5 degrees. The instrument consloe was crushed downward and to the left. The plexiglass cockpit enclosure, windows, right door frame, and roof were missing. Various sized sections of the cockpit windshield and cockpit enclosure were found attached to their fuselage mounting positions. Various sized pieces of the fuselage, windshield, and cockpit enclosure plexiglass were located on the parking lot surface between the truck and helicopter. The main rotor transmission's four forward tube mounts had separated between the transmision and their fuselage attachment points. The ends of the separated tubes had shear lips with the separated surfaces having a grey coloration and a consistent texture. The entire assembly was angled aft about 30 degrees and about 5 degrees to the left. The main rotor head and its three blades separated from the mast as a complete unit. This assembly was located under the helicopter's tail cone. The main rotor blades had spanwise bending and twisitng. Two blades had full spanwise spearation between the leading edge and top and bottom blade skins. The rotor head's 3 walking beam brackets had separated from the rotor head hub plate. Two of the three pitch links were separated between the walking beam and pitch horn. The hub nut was in place and had all 3 safeties attached. The blades droop stops were broken away from their mounts. All three rotor blade push-pull tubes were sticking out of the mast. The tubes caps had separated from their mounted position. The right side cyclic and collective control sticks had been removed from N86214's cockpit mounts. The left and right tail rotor pedals were found installed. Cyclic, collective, and tail rotor control continuity was established. The three main rotor blade push-pull tubes were present at the top of the main rotor mast. Their end caps had pulled out of the ends of each. The swashplate's collective walking beam had separated from the assembly just forward of its pivot point. The surface of this separation had a grainy texture and gray color. The longitudinal bellcrank had separated from its cabin bulkhead mount. The lateral trim actuator was extrended about 1-1/4 inches from the housing. According to the manufacturer, this corresponds to a mid-range setting. The longitudinal trim actuator was extended about 1/2 inch from the housing. The manufacturer stated this correspnds with mostly forward trim. The separated tail rotor control cables had broomed ends. Examination of the cable's individual strands showed they were necked. Both tail rotor blades were bent and twisted. One blade had its leading edge separated from the top and bottom blade skins. The tail rotor gear box housing was separated between the input and output gears. The control yoke had separated at the approximate midpoint. This assembly's separated surfaces had a grainy, constant grey colored surface appearance. The tail rotor's coupling ears were bent forward. The aft hanger bearing bolts had separated from their mounting surface. N86214's engine was rotated and thumb compression was obtained. The magnetos produced spark when rotated. During the engine's compression test rotation, the magneto drive gear was observed to rotate. Fuel was found inside the fuel injection distribution manifold. The rotor blade belt drive system had been dislocated from its normal mounting and was angled aft about 10 degrees. The drive belt tension roller was in the engaged position. The engine cooling fan blades had rotational damage. The shroud's interior had scrape marks parallel to the fan blade's rotational plane. MEDICAL AND PATHOLOGICAL INFORMATION An autopsy on the pilot was conducted on November 12, 1996, by Dr. Violette S. Hnilica, under the authority of Ford County Illinois Coroner Jeff Baines. According to the report, no significant pre-accident physical conditions were found. The forensic toxicology was conducted by the Federal Aviation Administration's Civil Aero Medical Institute. The results of that examination were negative for drugs, ethanol, cyanide, and carbon monoxide. ADDITIONAL INFORMATION During an interview, the pilot's helicopter flight instructor stated thst he had not shown the pilot how to "...translate rearward." He said he had taught the pilot how to get the nose of the helicopter into the wind for takeoff. He said he had told the pilot it was not safe to takeoff with a quartering tailwind. The instructor said he had not flown N86214 after the pilot had received his pilot certificate. He said the pilot used the helicopter for many activities, such as going to the store, giving rides, landing in tight places, and marking rocks in the farm fields while hovering over them. After the accident pilot had obtained his helicopter rating, the instructor said the pilot had shown him that he did not have personal limits when operating the helicopter.

Probable Cause and Findings

the pilot's inadequate preflight preparation and not maintaining control of the helicopter during its rearward flight. A factor was the pilot's over-confidence in his personal ability.

 

Source: NTSB Aviation Accident Database

Get all the details on your iPhone or iPad with:

Aviation Accidents App

In-Depth Access to Aviation Accident Reports