CHI96FA169

A witness reported seeing the airplane circling low overhead in a 'clockwise to rectangular' pattern. The witness observed the airplane turning southerly and descending, when it pitched up 45 degrees, and appeared to have stalled. The airplane then went into a 45 degree dive. The witness said the airplane sounded normal. The local police searched the hanger for signs of a suicide note, because the pilot's wife said he recently had been acting desponded. No such note was found. No mechanical failure/malfunction of the airframe, powerplant, or flight controls were discovered during the investigation.

History of flight

On May 23, 1996, at about 1245 central daylight time (cdt), a Beech Bonanza F-33A, N8273G, piloted by an instrument rated private pilot, impacted trees and terrain while maneuvering approximately twelve miles southeast of the Saint Clair Regional Airport, Saint Clair, Missouri. The airplane was destroyed by post-crash fire and the pilot sustained fatal injuries. Visual meteorological conditions prevailed at the time of the accident. The personal 14 CFR Part 91 flight was not operating on a flight plan. The flight departed from the Spirit of St. Louis Airport, Chesterfield, Missouri, at 1218 cdt.

According to a witness's written statement and telephone conversation on June 13, 1996, he saw the airplane circling low overhead the accident site in a clockwise to rectangular pattern. The witness thought he was going to land on a private landing strip nearby and didn't pay much attention to it until he commented to a neighbor, and said on the last pass as the aircraft went to the east and turning southerly while descending in altitude then the aircraft pitched up (45 degrees) in attitude, appeared to stall and pitched nose down. The witness did not realize the airplane had crashed as he lost sight of the airplane below the trees. The IIC asked if the airplane sounded abnormal? The witness said the airplane sound seemed to be normal, that's why he did not pay much attention to it.

On the day of the accident, a flight instructor talked with the pilot and stated that the pilot appeared to be in his usual temperament. The pilot was given a Biennial Flight Review (BFR) and Instrument Competency Check (ICC), by this flight instructor during the month of May, both with satisfactory results.

The Spirit of St. Louis Airport Director of Aviation received a telephone call from the Franklin County Sheriffs Office to conduct a search of the pilot's hangar for any signs of suicide. The reason the Sheriff's Office called "...was due to the fact that they had received information from the (pilot's) wife that indicated he had been despondent." No signs of suicide were found in the hangar.

Other damage

Trees and foliage were damaged during the impact.

Personnel information

The pilot was born December 27, 1925. He was the holder of a private pilot certificate with instrument and single engine land rating. He held a third class medical issued on May 1, 1995, with a limitation of wearing glasses for near vision. His most recent biennial flight review was on May 8, 1996 and a Instrument Competency Check was performed on May 16, 1996. He had accumulated a total of 3983.9 hours with an estimated 800 hours in this type of airplane at the time of the accident.

Aircraft information

The airplane was a Beechcraft Bonanza F33A, serial number CE- 1573, N8273G. The airplane had accumulated 774.5 hours time in service at the time of the accident. The engine had 774.5 hours total. The most recent inspection was conducted on April 22, 1996. The airplane's log books were destroyed in the post-crash fire.

Wreckage and impact information

The NTSB on-scene investigation began about 0800 cdt on May 24, 1996. The wreckage was located in a group of trees on the south end of an open field and was 195 degrees at 27 miles from the Spirit of Saint Louis Airport.

The wreckage path was located on a heading of 210 degrees. The first items in the path were several broken tree branches with clean cut marks. A second item was a tree stand about 23 feet high and 28 feet north of the main fuselage revealing three propeller slash marks spaced approximately 12 inches apart. Impact angle corresponds to a pitch attitude of approximately 45 degrees from the tree impact scars to the main wreckage. The right wing flap was found intact and separated at the inboard and outboard hinges at the base of the tree stand, exhibiting chordwise compression bending. The left wing was found 20 feet north of the main wreckage. The majority of the left wing was separated after impacting a second tree. The separated left wing's leading edge was wrapped and wedged against the tree trunk at approximately 4 feet above the ground with the wing tip embedded in the ground. The left wing corresponds to approximately a 30 degree left bank at impact using a protractor and level on the upper surface of the wing. The main wreckage, except for the powerplant and most of the empennage, had been destroyed by post crash fire. The fuselage was lying upright and facing 110 degrees. The majority of the separated right wing was found lying upright under the main wreckage. The engine remained attached to its mounts. The propeller had separated from the engine flange and was located 5 feet to the right of the wreckage. The landing gear struts were in the extended position and the flaps were up. The fuel selector valve assembly revealed a left tank setting.

The propeller hub of the three blade propeller was found intact. Examination of all three propeller blades exhibited leading edge gouges, torsional bending and chordwise scratching. Two blades exhibited 45 degree aft torsional twist at the midspan location of the blade. The three blades exhibited aft torsional corkscrew twisting at midspan location.

Control continuity was established from the cockpit control pedestal to the aileron, elevator, and both rudder pedals. No pre-existing anomalies were noted during the post accident examination of the engine, propeller and airframe.

Medical and pathological information

A post mortem and toxicological examination of the pilot was conducted on May 24, 1996, by the Franklin County Medical Examiner, Saint Louis, Missouri. No pre-existent anomalies were noted during this examination.

The pilot's toxicological analysis was performed by the FAA's Civil Medical Institute (CAMI) in Oklahoma City, Oklahoma. The toxicological examination of the specimens from the pilot were negative for the drugs scanned.

Tests and research

The engine was torn down and inspected under the supervision of the NTSB, on May 25, 1996, at Phoenix Aviation, Chesterfield, Missouri. The engine driven and standby vacuum pumps were intact and appeared undamaged. The engine turned by way of the crankshaft and continuity was established through all pistons and the accessory section. All spark plugs exhibited a light tan color. The fuel injection manifold and the fuel metering unit inlet fuel screen resembled a clean unobstructed appearance.

The propeller assembly was disassembled and inspected at McCauley, Vandalia, Ohio, under the supervision of the NTSB, on June 18, 1996. The results of the teardown revealed no anomalies that would have caused any mechanical malfunction prior the accident, and the propeller blades indicated they were in the High RPM range.

Additional data

Parties to the investigation were the Federal Aviation Administration; Teledyne Continental Motors; Raytheon Aircraft Company.

Following the on-scene portion of the investigation, the wreckage was released to an insurance representative of the owner on July 8, 1996.