MIA99LA069

NTSB accident investigation · Beech A36 · Charleston, SC · January 26, 1999

Accident · No injuriesLimited investigationFinal report
Date
January 26, 1999, 16:00 local (21:00 UTC)
Place
Charleston, SC
Injuries
1 uninjured
Damage
Substantial damage
Phase of flight
Enroute
Aircraft
N4976MBeech A36
Weather
Visual (VMC) · Day
Status
Completed · report April 19, 2001
Report
Approved by Office Director
FAA report
19990126000759A
Case key
45673

From the NTSB’s public API. By law, NTSB reports can’t be used as evidence in lawsuits over the accident.

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Probable cause

the total loss of engine power caused by an oil leak at the oil filter adapter, resulting in a broken connecting rod, a subsequent forced landing and impact with rough terrain.

Sequence of events

NTSB’s coding before 2008: each occurrence and phase of flight, and the causes and factors under it. The codes are defined in NTSB’s coding manual.

Loss of engine power(total) - mech failure/malfClimb - to cruise
Maintenance,inspection - improperOther maintenance personnel
Lubricating system,oil filter/screen - leak
Fluid,oil - exhaustionCause
Engine assembly,connecting rod - failureCause
Forced landingEmergency descent/landing
In flight collision with terrain/waterEmergency descent/landing
Terrain condition - rough/uneven

Analysis

The pilot reported that about 7 minutes after takeoff the airplane's engine lost oil pressure and started to lose oil, followed by a loss of engine power. The airplane started a descent that the pilot could not arrest, and continued to descend at a rate of about 100-200 feet per minute. The pilot then heard, 'a loud bang...a shudder occurred in the engine compartment, and the engine lost power.' The pilot banked the airplane, and headed towards a clearing. The engine compartment appeared to be on fire, and smoke began to enter the cockpit. He elected to make a forced landing in a field. The engine was examined at the crash site, and a hole was noted in the case at the No. 4 cylinder. Oil was observed on the No. 4 cylinder wall, the oil dip stick did not show any oil, and there was evidence that oil had leaked out of the engine. The engine was examined on February 12, 1999, and the examination revealed that oil had leaked at the engine oil filter adapter. In addition, there were more threads showing on one stud than on the other. A torque wrench was used to check torque on the nuts. It was noted that one nut rotated 1 1/2 rotations before reaching the specified torque. The other nut rotated 1 rotation before reaching torque. The oil filter adapter was removed for further examination, and revealed that the gasket was found with a gap at the corner with a opening of about 1/16 of an inch. It was concluded, that the leak caused the engine to exhaust the oil supply, causing the No. 4 cylinder connecting rod to fail, which resulted in a total loss of engine power.

Factual narrative

On January 26, 1999, about 1600 eastern standard time, a Beech A36, N4976M, registered to an individual lost engine power and impacted with the ground during a forced landing near Charleston, South Carolina. Visual meteorological conditions prevailed at the time, and a VFR flight plan was filed for the 14 CFR Part 91 personal flight. The airplane sustained substantial damage. The commercial-rated pilot reported no injuries. The flight was en route to Hilton Head, South Carolina, and had departed Charleston at 1545.

The pilot reported that during climb the airplane's engine lost oil pressure and started to lose oil, followed by a loss of engine power. He elected to make a forced landing in a field. The engine was examined at the crash site, and a hole was noted in the case at the No. 4 cylinder.

According to the pilot's summary and synopsis of circumstances, about 7 minutes after takeoff, he was cleared directly to Hilton Head, South Carolina, and was to maintain 2,500 feet. About 12 miles from the Charleston Airport, "...suddenly and without warning the propeller RPMs began to increased from 2,400 to 2,700." The pilot turned the airplane towards the Charleston Airport, advised Air Traffic Control (ATC) of the propeller overspeed condition, and that he intended to return to Charleston. He declared an emergency, and ATC cleared the airspace for the flight.

About 2 to 3 minutes after the initial increase in rpm, the propeller rpm increased to 3,000 rpm, and changed pitch. The airplane started a descent that the pilot could not arrest, and continued to descend at a rate of "about 100-200 feet per minute." The pilot then heard, "a loud bang...a shudder occurred in the engine compartment, and the engine lost power." The pilot banked the airplane, and headed towards a clearing. He said, the engine compartment appeared "...to be on fire, and smoke began to enter the cockpit." Before landing the pilot extended the landing gear, moved the fuel valve to the "OFF" position, turned off the mixture, and the electrical system. The landing site was a plowed field, and was plowed perpendicular to the direction of flight. The pilot elected to land straight ahead. At touchdown the airplane "appeared to slide first on its tail, then the landing gear hit a plowed furrow, and the aircraft came to an upright stop."

The engine was examined under the supervision of the FAA, on February 12, 1999, at Manning Aircraft Inc., Manning, South Carolina. Examination of the engine revealed that there was a hole in the case at the No. 4 cylinder. Oil was observed on the No. 4 cylinder wall, the oil dip stick did not show any oil, and there was evidence that oil had leaked out of the engine.

Low pressure air was introduced into the oil pressure line that ran to the gauge on the instrument panel, revealing an oil leak at the engine oil filter adapter. In addition, there were more threads showing on one stud than on the other. A torque wrench was used to check torque on the nuts. It was noted that one nut rotated 1 1/2 rotations before reaching the specified torque. The other nut rotated once before reaching torque. The oil filter adapter was removed for further examination, and revealed that the gasket was found with a gap at the corner with a opening of about 1/16 of an inch. It was concluded, that the leak caused the engine to exhaust the oil supply, causing the No. 4 cylinder connecting rod to fail, which resulted in a total loss of engine power (see Continental Motor's report, an attachment to this report).

Aircraft

Registration
N4976M
Reported as
Beech A36
Category
Airplane
Serial number
E-1271
Engine
Continental IO-520BA, 280 lbs thrust, reciprocating
Damage
Substantial damage
Flight
Business · Part 91
Registered owner
David Ames
Airworthiness certificate
Standard, Normal
Last inspection
Annual · November 15, 1998 · 20 hours before
Departed
CHS
Destination
HXD · Hilton Head, SC
Flight plan
VFR

Flight crew

As NTSB recorded them. NTSB leaves out names.

Role
Pilot
Age
54
Certificate
Commercial
Airplane ratings
Single-engine land
Instrument ratings
Airplane
Medical
Class 2, Valid Medical--w/ waivers/lim
Seat
Left
Flight hours
2,375 total · 1,875 in this make and model · 2,375 as pilot in command · 44 in the last 90 days · 15 in the last 30 days · 1 in the last 24 hours

Weather

Conditions
Visual (VMC) · Day
Wind
70° at 5 knots
Visibility
10 statute miles
Lowest ceiling
None
Temperature
64 °F, dew point 48 °F
Altimeter
30.00 inHg
Observed at
CHS, 12 nm away

FAA reports on this event · 1

The FAA’s own accident and incident reports, matched to the aircraft by N-number and date.