Piper J3C-65 accident near Egremont, Massachusetts, July 5, 2011
On July 5, 2011 at about 9:00 pm local time, a Piper J3C-65, registered N98550, was substantially damaged in an accident during landing near Egremont, Massachusetts (Walter J. Koladza Airport). It was a personal flight under general aviation rules (Part 91). 1 person had minor injuries; 1 other was unhurt. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
A partial loss of engine power due to the No. 4 intake and exhaust valves becoming lodged in the valve guides, which resulted from a lack of use, improper engine storage preparation, and improper return to service from indefinite storage.
Source: NTSB aviation accident database, copy made November 2, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- July 5, 2011 · about 9:00 pm local time · cases in 2011
- Place
- Egremont, Massachusetts · Walter J. Koladza Airport · cases near this airport · map
- Type
- Accident
- Injuries
- 1 person had minor injuries; 1 other was unhurt.
- Weather
- visual conditions (good weather)
- Aircraft
- Piper J3C-65 · all J3C-65s on the register
- Registration
- N98550 · no longer on the register · serial 18763
- Damage
- Substantial damage
- Flight
- Personal flight · general aviation rules (Part 91)
The NTSB's narrative final · quoted from the NTSB record
The pilot reported that the accident flight was the first flight in the airplane in 6 months. During the initial climb, the engine experienced a partial loss of power. The pilot checked the magnetos and carburetor heat but was unsuccessful in his attempts to regain full engine power. Subsequently, he chose to land the airplane between two houses. A postaccident engine compression test revealed that the Nos. 1 and 4 cylinders had low compression. The No. 1 rocker cover was removed, and the rocker arm was tapped with a mallet, which brought its compression to within normal range. Disassembly of the No. 4 cylinder revealed that it was leaking past the exhaust valve and through the exhaust system. In addition, disassembly revealed a scored intake valve stem and valve guide. The intake valve would not operate and had to be forcefully removed from the valve guide. According to the engine overhaul manual, scored valve stems can cause the engine to produce low power. The pilot did not report performing any of the procedures to return the engine to service from indefinite storage (that is, more than 90 days). Therefore, it is also likely that the engine was never prepared for indefinite storage and, thus, was not stored improperly for the 6 months it was not used before the accident flight. During storage, the No. 4 intake and exhaust valves most likely became lodged in the valve guides, which resulted in a partial loss of engine power and subsequent forced landing to a field. It is likely that, if the engine had been properly stored, the recommended lubrication would have prevented the valves from sticking and scoring and that, if the engine had been properly removed from storage, the scored valves may have been detected and replaced, either of which action could have prevented the accident.
The complete narrative as the NTSB published it. The NTSB's docket holds the report as a PDF and any photographs, statements and other documents from the investigation.
The factual record from the NTSB's investigation tables, in plain English
What happened, in order
- Powerplant sys/comp malf/fail during initial climb
- Loss of engine power (partial) during initial climb
- Collision during takeoff/land during landing defining event
- Collision with terrain or object (not controlled flight into terrain) during landing (landing roll)
The NTSB's findings
- cause Aircraft › Aircraft power plant › Engine (reciprocating) › Recip eng cyl section › Not used/operated other cases naming the engine
- cause Aircraft › Aircraft power plant › Engine (reciprocating) › Recip eng cyl section › Not serviced/maintained other cases naming the engine
- cause Personnel issues › Task performance › Use of equip/info › Use of policy/procedure › Not specified
- cause Personnel issues › Task performance › Maintenance › (general) › Not specified
Pilot
- Certificate: airline transport pilot, flight instructor, commercial pilot, flight engineer
- Ratings: multi-engine land; multi-engine sea; single-engine land; single-engine sea; instructor: airplane multi-engine; instructor: airplane single-engine; instructor: instrument airplane; instrument: airplane
- Flight time: 30,000 hours in all; 400 in this make and model; 225 in the last 90 days; 148 in the last 30 days; 25,000 as pilot in command; 3,300 on instruments
- Last flight review: October 24, 2010
- Medical certificate: Class 1 (with waivers/limitations)
- Seat: frt
- Injury: no injuries
The aircraft
- Airframe total time: 1,776 hours
- Last inspection: annual inspection, December 7, 2010
- Maximum gross weight: 1,220 lb
- Seats: 2
- Landing gear: fixed
- Engine: Cont Motor A&C65 SERIES (piston); 0 hours total
The flight
- Departed from: GBR Great Barringto MA at 9:00 pm
- Destination: GBR Great Barringto MA
- Flight plan: none
Weather at the time
- Light: daylight
- Wind: from 300° at 6 knots
- Visibility: 10 statute miles
- Sky: clear
- Temperature: 81°F (27°C), dew point 55°F (13°C)
- Altimeter: 29.93 inHg
- Observation at 9:54 pm from PSF, 16 miles away
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Flight crew | 1 | |||
| Passengers | 1 |
Documents from the investigation the NTSB's docket: the evidence folder behind the report
13 documents, released by the NTSB on November 22, 2013. View them here, or download them; the NTSB redacts some personal details before release, and this site shows the NTSB's own titles rather than its file names.
| # | Document | What it is | |
|---|---|---|---|
| 1 | Pilot/operator Aircraft Accident Report, NTSB Form 6120.1 | PDF, 9 pages | View Download |
| 2 | Pilot Statement | PDF, 1 page | View Download |
| 3 | Passenger Statement | PDF, 1 page | View Download |
| 4 | FAA Inspector Statement | PDF, 4 pages | View Download |
| 5 | Accident Flight Path Image (Google Earth) | PDF, 1 page | View Download |
| 6 | Postaccident Engine Compression Test | PDF, 1 page | View Download |
| 7 | Excerpts from Engine Maintenance Log | PDF, 3 pages | View Download |
| 8 | Excerpt from Engine Overhaul Manual: Troubleshooting | PDF, 7 pages | View Download |
| 9 | Excerpt from Engine Overhaul Manual: Storage Procedures | PDF, 3 pages | View Download |
| 10 | Photo 1: View of Airplane at Rest (Courtesy of FAA) | PDF, 1 page | View Download |
| 11 | Photo 2: View of Damaged Fuselage (Courtesy of FAA) | PDF, 1 page | View Download |
| 12 | Photo 3: View of Damaged Left Wing (Courtesy of FAA) | PDF, 1 page | View Download |
| 13 | Photo 4: View of Fuel Draining from Carburetor (Courtesy of FAA) | PDF, 1 page | View Download |
The same docket at the NTSB · documents without a copy here are fetched from the NTSB when you open them.
Other NTSB records under N98550 the same tail number, which may have belonged to a different aircraft at the time
Connections how this case links to the rest of the register
- N98550: not on the register today · the record of its deregistration
- Piper J-3 Cub 3,804 registered today · the model family and its accident history
- Piper 44,842 aircraft on the register
- Engine: Cont Motor A&C65 SERIES · as the NTSB recorded it
- Great Barrington Airport · nearest airport
- Accidents and incidents in Massachusetts 987 since 1982 · 90 in the last ten years
- Massachusetts 2,646 aircraft registered
- Other NTSB records under N98550 1 records · the number may have belonged to another aircraft at the time
The whole map of how records connect · these connections as data: /graph/accident/ERA11LA379.json.
The bigger picture in Aviation Analytics: accidents over time since 1982, by model, by phase of flight and conditions, by place and on the map.
Everything on this page comes from the NTSB's public records. The narrative, probable cause and findings are the NTSB's own words; the coded tables behind the report are written out in plain English, with pilots' ages, home towns and medical details left out. The documents and photographs are the NTSB's docket, shown as the NTSB released them. This site's own text does not name anyone involved, its policy at this time. A preliminary report can change; the final report usually follows one to two years later, and the page is refreshed when it does.