Plymouth Airport
Aircraft Accident/Incident Report

Plymouth, Massachusetts 02339
Monday, July 4, 2011 13:00 EDT

NTSB Narrative Summary Released at Completion of Accident

During initial climb, the engine began to run rough and experienced a partial loss of power. The pilot elected to land straight ahead into a cranberry bog. The pilot believed the loss of engine power was due to a stuck cylinder valve. Postaccident examination of the engine revealed that the No. 2 cylinder intake and exhaust valve springs exhibited excessive corrosion and carbon deposits, consistent with lack of use, which made them more susceptible to sticking. The extent of the corrosion was such that it presented over a long period of time and should have been addressed during routine maintenance. No other defects were noted with the engine that would have resulted in a partial loss of power. The airplane had been operated for 17 hours since its most recent annual inspection, which was completed 11 months prior to the accident. The engine had been operated for 256 hours since its most recent overhaul, which was completed more than 10 years prior to the accident. The same airplane was involved in a forced landing to a cranberry bog 8 years earlier due to a stuck cylinder valve.

NTSB Probable Cause Narrative

A partial loss of engine power during initial climb due to a stuck cylinder valve, which resulted from excessive corrosion and carbon deposits on the valve springs due to inadequate maintenance.

Event Information

Type of Event Accident
Event Date 7/4/2011
Event Day of the Week Monday
Time of Event 1300
Event Time Zone Eastern Daylight Time
Event City Plymouth
Event State MASSACHUSETTS
Event Country --
Zipcode of the event site 02339
Event Date Year 2011
Event Date Month 7
MidAir Collision Indicator No
On Ground Collision occurred ? No
Event Location Latitude 415430N
Event Location Longitude 0704400W
Event Location Airport Plymouth
Event Location Nearest Airport ID PYM
Indicates whether the acc/inc occurred off or on an airport Off Airport/Airstrip
Distance from airport in statute miles 1
Degrees magnetic from airport --
Airport Elevation 148
Weather Briefing Completeness --
Investigator's weather source Weather Observation Facility
Time of the weather observation 1252 Eastern Daylight Time
Direction of event from weather observation facility (degrees) --
Weather Observation Facility ID PYM
Elevation of weather observation facility 148
Distance of event from weather observation facility (units?) --
Time Zone of the weather observation EDT
Lighting Conditions Day
Lowest Ceiling Height --
Lowest Non-Ceiling Height --
Sky/Lowest/Cloud Conditions Clear
Sky Condition for Lowest Ceiling None
Visibility Runway Visual Range (Feet) --
Visibility Runway Visual Value (Statute Miles) --
Visibility (Statute Miles) 10
Air Temperature at event time (in degrees celsius) 29
Dew Point at event time (in degress fahrenheit) 18
Wind Direction (degrees magnetic) 280
Variable Wind Indicator Wind direction could be determined
Wind Speed (knots) 11
Wind Velocity Indicator --
Wind Gust Indicator Not Gusting
Wind Gust (knots) --
Altimeter Setting at event time (in. Hg) 29.79
Density Altitude (feet) --
Intensity of Precipitation --
METAR weather report --
Event Highest Injury None
On Ground, Fatal Injuries --
On Ground, Minor Injuries --
On Ground, Serious Injuries --
Injury Total Fatal --
Injury Total Minor --
Injury Total None 1
Injury Total Serious --
Injury Total All --
Investigating Agency NTSB
NTSB Docket Number (internal use) 29324
NTSB Notification Source FAA New England ROC
NTSB Notification Date --
NTSB Notification Time --
Fiche Number and/or location -used to find docket information --
Date of most recent change to record Nov 28 2011 1:22PM
User who most recently changed record kenj
Basic weather conditions Visual Meteorological Cond
FAA District Office --

Aircraft Involved

Aircraft #1

Aircraft Registration Number N150ET
NTSB Number ERA11LA383
Missing Aircraft Indicator --
Federal Aviation Reg. Part Part 91: General Aviation
Type of Flight Plan filed None
Flight plan Was Activated? No
Damage Substantial
Aircraft Fire None
Aircraft Explosion None
Aircraft Manufacturer's Full Name CESSNA
Aircraft Model 150L
Aircraft Series Identifier --
Aircraft Serial Number 15073072
Certified Max Gross Weight 1500
Aircraft Category Airplane
Aircraft Registration Class --
Aircraft is a homebuilt? No
Flight Crew Seats --
Cabin Crew Seats --
Passenger Seats --
Total number of seats on the aircraft 2
Number of Engines 1
Fixed gear or retractable gear Fixed
Aircraft, Type of Last Inspection Annual
Date of Last Inspection Aug 14 2010 12:00AM
Airframe hours since last inspection 17
Airframe Hours 4500
ELT Installed Yes
ELT Activated No
ELT Aided Location of Event Site No
ELT Type Unknown
Aircraft Owner Name Richard C Murphy
Aircraft Owner Street Address --
Aircraft Owner City Hanover
Aircraft Owner State MA
Aircraft Owner Country USA
Aircraft Owner Zipcode 02339
Operator is an individual? No
Operator Name Richard C Murphy
Operator Same as Owner? Yes
Operator Is Doing Business As --
Operator Address Same as Owner? Yes
Operator Street Address --
Operator City Hanover
Operator State MA
Operator Country USA
Operator Zip code 02339
Operator Code --
Owner has at least one certificate None
Other Operator of large aircraft? No
Certified for Part 133 or 137 Operation --
Operator Certificate Number --
Indicates whether an air carrier operation was scheduled or not --
Indicates Domestic or International Flight --
Operator carrying Pax/Cargo/Mail --
Type of Flying (Per_Bus / Primary) Personal
Second Pilot on Board No
Departure Point Same as Event Yes
Departure Airport Code PYM
Departure City Plymouth
Departure State MA
Departure Country USA
Departure Time 1300
Departure Time Zone EDT
Destination Same as Local Flt dest & departure same, accident can occur anywhere
Destination Airport Code PYM
Destination City Plymouth
Destination State MA
Destination Country USA
Specific Phase of Flight --
Report sent to ICAO? --
Evacuation occurred --
Date of most recent change to record Nov 28 2011 1:22PM
User who most recently changed record kenj
Since inspection or accident Time of Accident
Event Location Runway Number and Location N/A
Runway Length --
Runway Width --
Sight Seeing flight No
Air Medical Flight No
Medical Flight --