Piper J3C accident near Salisbury, Connecticut, August 13, 2017
On August 13, 2017 at about 9:00 pm local time, a 1946 Piper J3C, registered N98550, was substantially damaged in an accident during enroute (cruise) near Salisbury, Connecticut. It was an instructional flight under general aviation rules (Part 91). 2 people had minor injuries. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
An improper replacement of the crankshaft by maintenance personnel, which resulted in a failure of the crankshaft gear and total loss of engine power.
Source: NTSB aviation accident database, copy made November 2, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- August 13, 2017 · about 9:00 pm local time · cases in 2017
- Place
- Salisbury, Connecticut · map
- Type
- Accident
- Injuries
- 2 people had minor injuries.
- Weather
- visual conditions (good weather)
- Aircraft
- Piper J3C 65, built 1946 · all J3Cs on the register
- Registration
- N98550 · no longer on the register · serial 18763
- Damage
- Substantial damage
- Flight
- Instructional flight · general aviation rules (Part 91)
The NTSB's narrative final · quoted from the NTSB record
During cruise flight, the airplane experienced a total loss of engine power, and the flight instructor performed a forced landing into trees. The engine crankshaft was replaced about 4 years and about 317 hours of operation before the accident. Teardown examination of the engine revealed that the crankshaft gear screws were fractured, and the crankshaft gear was separated from the crankshaft. Fretting was observed near two of the four crankshaft screw holes and corresponded to two elongated screw holes on the crankshaft gear. The crankshaft and crankshaft gear did not contain a dowel pin as specified in the most current versions of the manufacturer's illustrated parts catalog and overhaul manual, which were published more than 2 years before the crankshaft replacement. Additionally, the crankshaft gear did not contain a dowel pin hole, which was consistent with a crankshaft gear for an older, different model engine. Both publications contained numerous instructions and references to use a crankshaft gear with a dowel pin hole and to align the gear to the crankshaft with a dowel pin, which would pilot the crankshaft gear on the crankshaft. Thus, it is likely that when the crankshaft was replaced, maintenance personnel did not use the most recent manuals and installed a crankshaft gear for a different engine, which led to the crankshaft gear's failure and the subsequent loss of all engine power.
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
- Aircraft maintenance event during prior to flight
- Powerplant sys/comp malf/fail during enroute (cruise) defining event
- Loss of engine power (total) during enroute (cruise)
- Off-field or emergency landing during emergency descent
- Collision with terrain or object (not controlled flight into terrain) during emergency descent
The NTSB's findings
- cause Personnel issues › Task performance › Maintenance › Replacement › Maintenance personnel
- cause Aircraft › Aircraft power plant › Engine (reciprocating) › Recip eng rear section › Failure other cases naming the engine
- Environmental issues › Physical environment › Object/animal/substance › Tree(s) › Contributed to outcome
Pilot
- Certificate: flight instructor, commercial pilot
- Ratings: single-engine land; instructor: airplane single-engine; instrument: airplane
- Flight time: 1,216 hours in all; 263 in this make and model; 115 in the last 90 days; 42 in the last 30 days; 1,097 as pilot in command; 444 on instruments
- Last flight review: December 22, 2016
- Medical certificate: Class 2 (without waivers/limitations)
- Seat: frt
- Injury: minor injuries
Dual student
- Certificate: student
- Flight time: 100 hours in all; 0 in this make and model
- Medical certificate: Class 3 (with waivers/limitations)
- Seat: rear
- Injury: minor injuries
The aircraft
- Airframe total time: 2,093 hours
- Last inspection: annual inspection, July 13, 2017
- Maximum gross weight: 1,220 lb
- Seats: 2
- Landing gear: fixed
- Engine: Continental Motors C90-8F (piston); 2,306 hours total
- Operator: Berkshire Aviation Enterprises INC
The flight
- Departed from: GBR Great Barringto MA at 8:40 pm
- Destination: GBR Great Barringto MA
- Flight plan: VFR
- A second pilot was aboard
Weather at the time
- Light: daylight
- Wind: from 320° at 9 knots, gusting 14
- Visibility: 10 statute miles
- Sky: a few clouds at 5,500 ft
- Temperature: 82°F (28°C), dew point 57°F (14°C)
- Altimeter: 29.93 inHg
- Observation at 8:51 pm from BDL, 25 miles away
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Flight crew | 1 | |||
| Passengers | 1 |
Photographs from the investigation 2 pictures from the NTSB's docket, as the NTSB released them
The NTSB's photographs with the NTSB's captions, at screen size. Open a picture to see it full size or to report one that should not be shown.
Documents from the investigation the NTSB's docket: the evidence folder behind the report
7 documents, released by the NTSB on December 10, 2018. 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 | Interview Summary | PDF, 1 page | View Download |
| 3 | Excerpts from Engine Logbook | PDF, 7 pages | View Download |
| 4 | Photo Array | PDF, 2 pages · our copy | View Download |
| 5 | Manufacturer Report of Engine Teardown Examination | PDF, 17 pages | View Download |
| 6 | Evidence Control Form | PDF, 1 page | View Download |
| 7 | Statement of Party Representatives to NTSB Investigation | PDF, 9 pages | 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: Continental Motors C90-8F 30 aircraft carry this series today · as the NTSB recorded it
- Great Barrington Airport · departed from
- Accidents and incidents in Connecticut 522 since 1982 · 68 in the last ten years
- Connecticut 1,610 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/ERA17LA275.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.