Siai-Marchetti S205-22R accident near Okeechobee, Florida, November 5, 2011
On November 5, 2011 at about 2:45 pm local time, a Siai-Marchetti S205-22R, registered N729WA, was substantially damaged in an accident during initial climb near Okeechobee, Florida (River Acres Airport). It was a personal flight under general aviation rules (Part 91). No one was hurt; 1 person was on board or involved. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
A partial loss of engine power due to a failure of the drive bearings in the alternator drive system. Contributing to the accident was the inadequate maintenance.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- November 5, 2011 · about 2:45 pm local time
- Place
- Okeechobee, Florida · River Acres Airport · map
- Type
- Accident
- Injuries
- No one was hurt; 1 person was on board or involved.
- Weather
- visual conditions (good weather)
- Aircraft
- Siai-Marchetti S205-22R
- Registration
- N729WA · no longer on the register · serial 388
- Damage
- Substantial damage
- Flight
- Personal flight · general aviation rules (Part 91)
The NTSB's narrative final · quoted from the NTSB record
According to the pilot, during climbout, the engine lost partial power and was running rough. The pilot was unable to restore the engine to full power and made a forced landing in a river. Examination and partial disassembly of the engine revealed that the alternator drive adaptor did not function, the alternator drive gear exhibited extensive wear, and the gear teeth were smeared. The alternator drive bearings were not present, and metal particles were found throughout the oil system in the engine. In addition, the engine alternator drive belt that was driven by the engine was not located and the alternator adjustment was on the maximum setting. According to the engine maintenance log, the alternator was replaced by the pilot/owner and was signed off by an airframe and powerplant mechanic. The airplane had accumulated 2 hours of flight time since the alternator was replaced by the pilot/owner. It is likely that the added pressure to the crankshaft from the alternator drive shaft and the metal in the engine resulted in the engine losing partial 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
- Loss of engine power (partial) during initial climb defining event
- Ditching during emergency descent
The NTSB's findings
- cause Aircraft › Aircraft systems › Electrical power system › Alternator › generator drive sys › Failure
- factor Personnel issues › Task performance › Maintenance › (general) › Maintenance personnel
- cause Aircraft › Aircraft power plant › Engine (reciprocating) › (general) › Failure
Pilot
- Certificate: private
- Ratings: single-engine land
- Flight time: 250 hours in all; 40 in this make and model; 28 in the last 90 days; 12 in the last 30 days; 180 as pilot in command
- Last flight review: June 16, 2010
- Medical certificate: Class 3 (with waivers/limitations)
- Seat: left
- Injury: no injuries
The aircraft
- Airframe total time: 2,118 hours
- Last inspection: annual inspection, March 15, 2011
- Seats: 4
- Landing gear: retractable
- Engine: Franklin 6A350C1R (piston); 0 hours total
The flight
- Departed from: FD70 Okeechobee FL at 2:44 pm
- Destination: F45 Palm Beach FL
- Flight plan: none
Weather at the time
- Light: daylight
- Wind: from 340° at 12 knots, gusting 15
- Visibility: 10 statute miles
- Sky: clear
- Temperature: 63°F (17°C), dew point 55°F (13°C)
- Altimeter: 30.02 inHg
- Observation at 2:35 pm from OBE, 10 miles away
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Flight crew | 1 |
Documents from the investigation the NTSB's docket: the evidence folder behind the report
The docket, the folder of records gathered during an investigation (maintenance records, photographs, witness statements, examinations), has not been read from the NTSB for this case yet; the list appears here once it has. Open the docket at the NTSB.
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.