1 fatality

18 Dec 2008: BEECH 36 (N7472N) — Louisville, KY

Louisville, KY, United States

On 18 Dec 2008, a BEECH 36 (registration N7472N) was involved in an aviation accident near Louisville, KY. One person was killed. Investigators recorded the probable cause as: The pilot’s continued operation of the aircraft with known deficiencies. Contributing to this accident was the improper sealing of the engine case during overhaul. This summary draws on records from NTSB; 12 related events involving the same aircraft type or operator are linked below.

SourcesNTSBPrimary reportUpdated 1778583330Data APIEditorial standards

On December 18, 2008, a Beech 36 crashed in a Louisville golf community after the pilot reported an engine failure. The pilot was killed and the aircraft sustained substantial damage.

Flight History

On December 18, 2008, at approximately 0355 eastern standard time, a Beech 36, N7472N, crashed in an open field within a golfing community in Louisville, Kentucky. The flight originated from Chicago Midway International Airport (MDW) and was destined for Bowman Field Airport (LOU) in Louisville. Instrument flight rules (IFR) and an IFR flight plan were in effect. Night instrument meteorological conditions prevailed.

Before departure, the pilot experienced a problem with the airplane after refueling at MDW on December 17, 2008. The airplane returned to the fixed base operator (FBO) and was placed in a hangar. A maintenance facility was contacted but could not inspect the aircraft until the morning. The pilot attempted to start the engine several times and departed around 0220 on December 18.

A witness in the golf community reported seeing the airplane flying low, about 500 feet above ground, with no lights on. The airplane turned right and descended. She then heard a "thud and a boom."

According to the Louisville Approach controller, the pilot was cleared for the RNAV GPS approach to runway 24 at LOU. Shortly after, the pilot reported an emergency due to an engine failure. The airplane was discovered later that morning, around 0600, by local fire department personnel.

Pilot Information

The 25-year-old pilot held a commercial pilot certificate with single-engine, multiengine, and instrument ratings, as well as a flight instructor certificate with single-engine and instrument ratings. He was issued a first-class medical certificate on February 21, 2008, with no limitations. He had accumulated 2,300 total flight hours at that time.

Aircraft Information

The Beech 36 (serial number E-32) was a six-place, low-wing, single-engine airplane with retractable landing gear and a variable-pitch propeller. It was manufactured in 1968 and powered by a Continental IO-520-BA engine rated at 285 horsepower. The engine was overhauled in December 2007, and the propeller was overhauled in August 2008. The pilot purchased the airplane in July 2008 and had flown 40 hours in it. The engine had 58 hours since overhaul.

Weather Conditions

The closest weather observation was at Bowman Field Airport (LOU), 7 miles southwest of the accident site. The 0353 METAR reported winds from 330 degrees at 3 knots, visibility 6 statute miles, mist, overcast clouds at 800 feet, temperature 0 degrees Celsius, dew point minus 2 degrees Celsius, and altimeter 30.33 inches of mercury.

Wreckage and Impact

The wreckage was located on a golf course fairway between residential homes and tall trees. Impact marks indicated the airplane was on a course of about 340 degrees at approximately 30 feet above ground level when the right wing struck a tree. The right wing and landing gear separated at the wheel well. Ground scars were consistent with an inverted impact. The main impact scar, containing windshield and vertical fin debris, was 119 feet north of the tree. The airplane came to rest inverted approximately 175 feet from the tree, with left and nose landing gear extended and the cabin roof crushed.

Post-recovery examination established flight control continuity. The left wing leaked fuel from impact damage, and 6 gallons of aviation fuel were recovered from the left fuel bladder. The right fuel bladder was ruptured. Fuel was observed at the engine-driven fuel pump. The engine would not rotate and was retained for examination.

Engine Examination

An engine teardown at Teledyne Continental Motors (TCM) with NTSB oversight revealed that the crankshaft and counterweight assembly were fractured through at the forward fillet radius of the number 2 main bearing journal. The number 2 main bearing journal exhibited scoring consistent with bearing rotation, and fragments were found in the oil sump. The number 3 main bearing journal was fractured at the rear fillet area.

Further examination of the crankcase halves by the NTSB Materials Laboratory showed silk thread patterns and gasket making material on the sealing surfaces of the main bearing bosses, which is not part of the manufacturer's maintenance instructions (TCM Service Information Letter 99-2B). The number 2 main bearing boss was severely damaged on both case halves, including rotational mechanical gouging and mushrooming deformation.

Medical Examination

The Jefferson County Coroner's Office conducted a postmortem examination and determined the cause of death was blunt force trauma. Toxicology testing by the FAA Civil Aeromedical Institute detected no carbon monoxide, cyanide, ethanol, or drugs.

Contributing factors

Causes

Maintenance personnelPilot

Other contributing factors

Malfunction