CHI99GA155

The helicopter departed controlled flight while en route to the Poplar Bluff Airport, Poplar Bluff, Missouri. A witness stated that the helicopter appeared to be 450 feet agl. The helicopter was then reported by the witness to have made three to four rotations during its descent. The OH-58A/C lists procedures for the 'COMPLETE LOSS OF TAIL ROTOR THRUST'. Examination of the tail rotor drive shaft revealed a 45-degree torsional fracture. There was rotational scoring near the fracture area on the interior housing for the tail rotor drive shaft. An elastic material with navy blue yarns was found wrapped around the tail rotor. The yarns were consistent with those of a navy blue warm up jacket found along the reported flight path. The helicopter's entry doors were removed for the flight.

History of flight

On May 17, 1999, at 1608 central daylight time, a Bell OH-58A, N77MP, operated by the Missouri State Highway Patrol, was destroyed on impact with terrain in the city of Poplar Bluff, Missouri. Visual meteorological conditions prevailed at the time of the accident. The 14 CFR Part 91 public-use flight was not operating on a flight plan. The private pilot and passenger sustained fatal injuries. The local photography flight departed Dexter Municipal Airport, at approximately 1400, and later diverted to Malden Municipal Airport (MAW), Missouri, due to an approaching storm. The flight then departed MAW, at approximately 1545, en route to the Poplar Bluff Municipal Airport (POF), Poplar Bluff, Missouri.

A witness reported that, while he was driving, he saw a helicopter flying southbound at an altitude of approximately 350-400 feet above ground level. He stated that he saw what was possibly a large bird hit the rear rotor of the helicopter, after which two objects, approximately the size of grapefruits, fell to the ground. He further stated that the objects were falling slowly as if they were light and not fast like something heavy.

A second witness reported, "...I noticed a Black H58 helicopter aloft moving from my left to my right. It appeared to be about 450' [feet] agl, nose slightly below level, when it suddenly pitched up and rotated slightly below level, when it suddenly pitched up and rotated sharply to its left. It seemed to simultaneously pause forward motion for a moment, then began a counterclockwise descent. It made three or four complete rotations before it disappeared behind some trees...".

Personnel information

The 41 year old Missouri State Highway Patrol pilot held a private pilot certificate with airplane single engine land, instrument airplane and helicopter ratings. Federal Aviation Administration (FAA) records indicated no history of aircraft accidents, incidents or enforcement action. Logbook entries showed that the pilot had accumulated a total airplane flight time of 2,850.6 hours as of January 7, 1999 and a total rotorcraft flight time of 580.9 hours as of the last logbook entry on November 19, 1998. He received a second class medical with no restrictions on January 27, 1999. Pilot logbook entries showed that the pilot received 26.9 hours of dual instruction and accumulated 51.7 hours in rotorcraft prior to obtaining a rotorcraft rating on June 5, 1997 which was conducted in the accident aircraft. The Missouri Highway Patrol reported that the pilot had accumulated an airplane flight time of 17 hours and a helicopter flight time of 18.6 hours from January 5, 1999 to May 17, 1999. Training records indicated that the pilot received recurrent airplane training in 1994, 1995, 1997 and 1999. The pilot received 8.0 hours of recurrent training in a airplane simulator from January 6, 1999 to January 7, 1999. A biennial flight review, referencing FAA Regulation 61.56(e), FAA Pilot Proficiency Award Program, was logged in the pilot's logbook on January 7, 1999. There were no logbook entries indicating that the pilot had received helicopter training after obtaining his rotorcraft rating.

Aircraft information

The helicopter was transferred from the United States Army to the Missouri State Highway Patrol through a surplus program under the National Defense Authorization Act on September 6, 1996. The helicopter had a total airframe time of 3,896 hours when it was received by the Missouri State Highway Patrol which then operated it as a public-use aircraft. A 100/200-hour inspections of the engine and airframe were completed on November 30, 1998 at a total engine time of 1,980.9 hours and a total airframe time of 4,412.9 hours. On May 16, 1999, the helicopter had accumulated an approximate total engine time of 2,011 hours and an approximate total airframe flight time of 4,443 hours. The engine had accumulated a approximately 959 hours since overhaul.

The helicopter was equipped with two cockpit and two cabin entry doors. The aircraft had been operated on previous flights with the doors removed during missions involving search, rescue, marijuana eradication, and photo flights. The cockpit entry doors were removed for the accident flight for the purposes of photography.

Airport information

MAW was approximately 23 nmi on a magnetic heading of 116 degrees from the accident site.

POF was approximately 5 nmi on a magnetic heading of 091 degrees from the accident site.

Wreckage and impact information

A search by the parties to the investigation found a navy blue warm-up jacket along the flight path of the helicopter which was reported by witnesses. The navy blue warm-up jacket was approximately 1,579 feet on a magnetic heading of 040 degrees from the helicopter. The jacket was found lying on a tree stump located at the edge of a grass field belonging to a school. The jacket was muddy and torn in several areas, and did not have an attached hood or waistband.

The helicopter was found in an upright position between a one-story brick office building and an embankment. The embankment was approximately 10 feet in height on top of which were trees and a residential neighborhood. The helicopter was in an upright position and orientated on a magnetic heading of 143 degrees which was approximately parallel to the wall of the office building.

The main rotor and tail rotor were intact with their respective control linkages. The tail rotor blade did not have any scoring or gouging in the rotational direction. There was a 45-degree fracture of the tail rotor drive shaft. The fracture was located between two hanger bearings which were inline with the leading and trailing edges of the horizontal stabilizers. The surface of the tail cone and tail rotor drive shaft housing exhibited scoring, in the lateral direction, in an area around the fracture. There was a white elastic cloth material, estimated to be 24 inches by 1/2 inches in dimension, wrapped and stretched around the tail rotor shaft, pitch change links and blades. There were surface imprints similar to the fiber pattern of the elastic material on both tail rotor blades and on the surface of the left horizontal stabilizer.

Flight control and engine control continuity was established. Continuity of the transmission and tail rotor gear box was established. Both transmission chip detectors and tail rotor chip detector did not contain metallic contaminants. Both engine igniters did not contain contaminants. The engine stator and rotor blades were intact. Debris similar to the surrounding soil of the accident site was found in the exhaust section of the engine.

Medical and pathological information

An autopsy was conducted by the Butler County coroner.

FAA toxicological results tested positive for pseudoephedrine, ephedrine, and phenylpropanolamine. Pseudoephedrine is a decongestant, available over-the-counter, often known by the trade name Sudafed. Ephedrine is an asthma medication, available over-the-counter in tablet form, often known by the trade name Primatene. It is also available in many nutritional supplements such as ephedra, also known as Ma Huang. Phenylpropanolamine is a metabolite of ephedrine, also available itself as an over-the-counter decongestant.

Tests and research

Sections of Advisory Circular 61-91H Pilot Proficiency Award Program states the following:

6. Participation in the pilot proficiency award program in lieu of a flight review.

A pilot need not accomplish the flight review requirements of 14 CFR part 61, 61.56 if, since the beginning of the 24th calendar month before the month in which the pilot acts as pilot in command, he or she has satisfactorily completed one or more phases of an FAA-sponsored Pilot Proficiency Award Program in an aircraft (reference 61.56(f)).

7. Training requirements phases I through xx.

Minimum requirements, which include spec