Cessna 207 accident near Marathon, Florida, December 29, 2021
On December 29, 2021 at about 4:22 pm local time, a 1971 Cessna 207, registered N1596U, suffered minor damage in an accident during enroute near Marathon, Florida. It was flown under charter and air-taxi rules (Part 135). 1 person was seriously injured and 2 people had minor injuries. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
A total loss of engine power due to the failure of the No. 2 bearing, which resulted in the No. 2 connecting rod failing due to fatigue, high heat, and stress.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- December 29, 2021 · about 4:22 pm local time
- Place
- Marathon, Florida · map
- Type
- Accident
- Injuries
- 1 person was seriously injured and 2 people had minor injuries.
- Weather
- visual conditions (good weather)
- Aircraft
- Cessna 207 UNDESIGNAT, built 1971 · all 207s on the register
- Registration
- N1596U · no longer on the register · serial 20700196
- Damage
- Minor damage
- Flight
- Flight · charter and air-taxi rules (Part 135)
The NTSB's narrative final · quoted from the NTSB record
Shortly after departure, the engine lost total power and the pilot was forced to ditch in open water; the occupants egressed and were subsequently rescued by a recreational vessel. Examination of the engine revealed a fracture hole near the No. 2 cylinder, which was likely the result of the No. 2 cylinder connecting rod fracturing in fatigue as a result of high heat and high stress associated with failure of the No. 2 bearing. The fatigue fracture displayed multiple origins consistent with relatively high cyclic stress, which likely occurred as excessive clearances developed between the bearing and the crankshaft journal. The No. 2 connecting rod bearing may have failed due to a material defect in the bearing itself or due to a disruption in the oil lubrication supply to the bearing/journal interface. Either situation can cause similar damage patterns to develop, including excessive heating and subsequent bearing failure.
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
- Loss of engine power (total) during enroute defining event
- Ditching during landing
The NTSB's findings
- Aircraft › Aircraft power plant › Engine (reciprocating) › Recip eng oil sys › Failure
- Aircraft › Aircraft power plant › Engine (reciprocating) › Recip engine power section › Failure
Pilot
- Certificate: commercial pilot
- Ratings: single-engine land; instrument: airplane
- Flight time: 1,463 hours in all; 176 in this make and model; 73 in the last 90 days; 16 in the last 30 days
- Last flight review: October 13, 2021
- Medical certificate: Class 2 (without waivers/limitations)
- Seat: left
- Injury: serious injuries
The aircraft
- Airframe total time: 13,496 hours
- Last inspection: annual inspection, September 27, 2021; 2 hours since
- Maximum gross weight: 3,600 lb
- Seats: 7
- Landing gear: fixed
- Engine: Continental Motors IO-520F (piston); 3,728 hours total
The flight
- Departed from: MTH Marathon FL at 9:10 pm
- Destination: APF Naples FL
Weather at the time
- Light: daylight
- Wind: from 140° at 4 knots
- Visibility: 10 statute miles
- Sky: clear
- Temperature: 79°F (26°C), dew point 70°F (21°C)
- Altimeter: 30.04 inHg
- Observation at 4:53 pm from MTH, 11 miles away
Weather report (METAR): KMTH 292153Z AUTO 14004KT 10SM CLR 26/21 A3004 RMK AO2 SLP171 T02560211
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Flight crew | 1 | |||
| Passengers | 2 |
Documents from the investigation the NTSB's docket: the evidence folder behind the report
10 documents, released by the NTSB on May 10, 2023. 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, 13 pages | View Download |
| 2 | NTSB Engine and Airframe Factual Report | PDF, 10 pages | View Download |
| 3 | Materials Laboratory Factual Report 22-070 | PDF, 6 pages | View Download |
| 4 | Photo Array | PDF, 10 pages | View Download |
| 5 | Record of Conversation (Mechanic) | PDF, 2 pages | View Download |
| 6 | Record of Conversation (Passenger 1) | PDF, 2 pages | View Download |
| 7 | Maintenance Record Excerpts | PDF, 15 pages | View Download |
| 8 | Figures from Report | PDF, 3 pages | View Download |
| 9 | Statement of Party Representatives to NTSB Investigation | PDF, 1 page | View Download |
| 10 | Release of Aircraft Wreckage, NTSB Form 6120.15 | PDF, 7 pages | View Download |
The same docket at the NTSB · documents without a copy here are fetched from the NTSB when you open them.
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 never names anyone involved. A preliminary report can change; the final report usually follows one to two years later, and the page is refreshed when it does.