ERA16LA217

NTSB accident investigation · Beech P35 · Westerly, RI · June 18, 2016

Accident · Minor injuriesLimited investigationFinal report
Date
June 18, 2016, 12:35 local (16:35 UTC)
Place
Westerly, RI
Injuries
1 minor
Damage
Substantial damage
Phase of flight
Enroute
Aircraft
N112MBBeech P35
Defining event
Enroute-cruise: Loss of engine power (total)
Weather
Visual (VMC) · Day
Status
Completed · report September 11, 2018
Report
Approved by Office Director
NTSB office
Eastern Region Aviation
Parties
FAA/FSDO, Continental Motors Inc.
FAA report
20160618007299A
Case key
93404

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

On this page

Probable cause

A total loss of engine power due to inadequate maintenance of the oil filter adapter, which resulted in an oil leak and subsequent oil starvation to the engine.

Findings · 3

NTSB’s coded findings. Those marked are part of the probable cause; the rest are factors or other findings. Under each, the cases with the same finding.

Engine (reciprocating): recip eng oil sysAircraft › Aircraft power plant · Incorrect service/maintenanceBeech P35: 2 casesAll aircraft: 130 casesProbable cause
Maintenance: scheduled/routine maintenancePersonnel issues › Task performance · Maintenance personnelBeech P35: 1 caseAll aircraft: 320 casesProbable cause
Fluids: oilAircraft › Fluids/misc hardware · Fluid levelBeech P35: 1 caseAll aircraft: 174 casesProbable cause

Sequence of events

The events NTSB coded, in order, by phase of flight. The defining event is the one that best describes the accident. Under each, the cases with the same event anywhere in their sequence.

Analysis

During cruise flight over open water, the airplane experienced a total loss of engine power, and the private pilot ditched the airplane. Subsequent examination of the engine revealed that the oil filter adapter was loose and the fiber gasket was torn and partially extruded. Because of these conditions, oil leaked from the engine, which led to the failure of the Nos. 2 and 4 connecting rods due to a lack of oil lubrication. The oil filter adapter was not original equipment on the engine; it was installed under a supplemental type certificate which required that the oil filter adapter fiber gasket be replaced anytime the oil filter adapter was removed from the engine and reinstalled and every 300 hours or 3 years, whichever occurred first. Maintenance records indicated that the oil filter adapter was installed about 4 1/2 years before the accident. No other maintenance entries or records pertaining to the inspection of the fiber gasket was noted during the 4 years before the accident, and no record concerning the installation of a new oil filter adapter fiber gasket was located.

Factual narrative

On June 18, 2016, about 1235 eastern daylight time, a Beech P35 airplane, N112MB, ditched in Block Island Sound after a total loss of engine power near Westerly, Rhode Island. The private pilot received minor injuries. Visual meteorological conditions prevailed and a visual flight rules flight plan was filed, but not activated, for the personal flight. The airplane was owned and operated by the pilot and the flight was conducted under the provisions of Title 14 Code of Federal Regulations Part 91. The flight originated from Francis S. Gabreski Airport (FOK), Westhampton Beach, New York, with an intended destination of Taunton Municipal Airport (TAN), Taunton, Massachusetts. In an interview with a Federal Aviation Administration (FAA) Inspector, the pilot stated that while en route, he attempted to reduce the manifold pressure, however it did not respond. Next, he heard a "loud bang," followed by oil covering the windscreen of the airplane, and the engine lost total power. Furthermore, the pilot reported that the propeller rpm "was all over the place" prior to the total loss of engine power. He ditched about 2 miles west of Westerly State Airport (WST), Westerly, Rhode Island. After landing in the water, the pilot egressed without incident, and the airplane sank. The airplane was recovered and an examination revealed that the wings, empennage, and fuselage sustained substantial damage during the accident sequence. In addition, a hole was noted in the top of the engine crankcase. According to FAA records, the airplane was manufactured in 1962 and was powered by a 260-hp Continental Motors, Inc., IO-470-N21B reciprocating engine. The airplane's most recent annual inspection was completed on December 29, 2015, at a recorded tachometer reading of 2,812 hours, airframe total time of 5,186 hours, and engine time since major overhaul of 99 hours. The pilot indicated that, at the time of the accident, the engine had accumulated 109 hours of engine time since major overhaul. The engine was equipped with an F&M Enterprises Inc. (model C6LC-L) oil filter adapter, which was not original equipment, but could be installed on the engine under FAA Supplemental Type Certificate (STC) number SE09356SC. The oil filter adapter installation was completed on December 1, 2011, which was the same time as the engine overhaul. A review of the oil filter adapter manufacturer's installation instructions revealed that, during installation, the oil filter adapter body was torqued to 65 ft lbs, and it should be retorqued after 10 hours of operation. The oil filter adapter required one fiber gasket and one copper crush gasket to be used in the installation. In addition, manufacturing guidance indicated that at each annual inspection or 100-hour inspection, the mechanic was to inspect the oil filter adapter for oil seepage, the safety wire, the security of the adapter, and record the results of the inspections in the logbook. Maintenance guidance for the oil filter adapterincluded instructions for replacing the gaskets anytime the oil filter adapter was removed from the engine and reinstalled, and at 300 hours or 3 years, whichever occurred first. The most recent maintenance on the oil filter adapter recorded in the engine logbook was completed on August 25, 2012, at an engine time since major overhaul of 40 hours. An examination of the engine revealed that the oil filter adapter tightening break away torque was 13.58 ft lbs and the loosening torque was less than 13.33 ft lbs, as the torque wrench would not register any lower torque. Furthermore, the fiber gasket located between the adapter and the engine was torn and partially extruded from the adapter. The oil filter adapter was removed and the fiber gasket was removed. The fiber gasket was torn in one location and the crush deformation not symmetrical around the gasket. In addition, the Nos. 2 and 4 connecting rods had separated from the crankshaft. All connecting rod journals exhibited thermal damage and signatures consistent with lubrication distress.

Aircraft

Registration
N112MB
Reported as
Beech P35 (NO SERIES)
Category
Airplane
Serial number
D-6945
Built
1962
Airframe hours
5,186
Engine
Continental Motors IO-470-N21B, 260 horsepower, reciprocating
Damage
Substantial damage
Flight
Personal · Part 91
Airworthiness certificate
Standard, Utility
Last inspection
Annual · December 29, 2015 · 10 hours before
Departed
FOK · Westhampton Beach, NY
Destination
TAN · Taunton, MA
Flight plan
VFR
Airport
WST · Westerly State
Equipment
Handheld GPS, Auto-pilot, Electronic flight bag or handheld device

Matched to the registry by N-number and the event date; the registry’s history has gaps, so older matches can be wrong. Compare the reported make and model.

Flight crew

As NTSB recorded them. NTSB leaves out names.

Role
Pilot
Age
62
Injuries
Minor
Certificate
Private
Airplane ratings
Single-engine land
Instrument ratings
Airplane
Medical
Class 3, With waivers/limitations
Seat
Left
Restraint
Lap only
Flight hours
664 total · 222 in this make and model · 525 as pilot in command · 10 in the last 90 days

Weather

Conditions
Visual (VMC) · Day
Wind
170° at 8 knots
Visibility
10 statute miles
Lowest ceiling
None
Temperature
77 °F, dew point 50 °F
Altimeter
30.23 inHg
Observed at
WST, 2 nm away

Docket · 7

The files NTSB released with the investigation on May 16, 2018, on NTSB’s docket system: statements, records, photos and specialists’ reports. 13.5 MB in all.

FAA reports on this event · 1

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