Bell OH-58A accident near Ocala, Florida, October 11, 2009
On October 11, 2009, a Bell OH-58A (helicopter), registered N911AF, was substantially damaged in an accident during approach (VFR pattern final) near Ocala, Florida (Ocala International-Jim Taylor airport). It was a public-use flight under public-use (government) rules. No one was hurt; 2 people were on board or involved. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
The excessive wear and failure of engine governor components for undetermined reasons, which resulted in a loss of engine power.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- October 11, 2009
- Place
- Ocala, Florida · Ocala International-Jim Taylor · map
- Type
- Accident
- Injuries
- No one was hurt; 2 people were on board or involved.
- Weather
- visual conditions (good weather)
- Aircraft
- Bell OH-58A · all OH-58As on the register
- Registration
- N911AF · registry record · serial 71-20765
- Damage
- Substantial damage
- Flight
- Public-use flight · public-use (government) rules
The NTSB's narrative final · quoted from the NTSB record
The pilot stated that while on final approach for landing, at about 20 knots and 120 feet above ground level, he felt a "vibration" and the helicopter experienced a loss of engine and rotor rpm. The pilot stated that he lowered the collective for an immediate landing and heard the low-rotor warning horn during the descent. The helicopter experienced a hard landing and rotated to the left after touchdown. Once the helicopter settled, the pilot closed the throttle and exited the helicopter. Initial examination of the helicopter revealed no preimpact mechanical anomalies. The engine was then removed from the helicopter and the turbine governor was removed from the engine. As the turbine governor was removed from the engine, several rolling elements (balls) spilled from the governor and were not recovered. Disassembled portions of the governor were forwarded to the NTSB Materials laboratory and examination of the components revealed the lubricant used was consistent with what was prescribed by the manufacturer. Further examination revealed displacement of the governor driveshaft, deformation of a bearing seal, rotational damage on bearing lands and spacers, as well as spalling on rolling components of the governor. The damage was consistent with wear over an extended period, and neither the cause nor the sequence of wear and failure of the examined components could be determined. Examination of maintenance records revealed that the governor was in service 30 hours beyond its 2,000-hour time-before-overhaul (TBO) interval, but that under the military maintenance program by which the helicopter was maintained, TBO intervals could be adjusted plus or minus 75 hours to align with other scheduled maintenance. Examination of the manufacturer's Operator's Manual revealed that the loss of engine power occurred at an altitude that fell in the "avoid area" of the Height Velocity diagram. According to the manual, “Flight conducted within the avoid area of the chart (figure 9-3) exposes the helicopter to a high probability of damage despite the best efforts of the pilot."
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 approach (VFR pattern final) defining event
- Off-field or emergency landing during emergency descent
- Hard landing during landing (flare/touchdown)
The NTSB's findings
- cause Aircraft › Aircraft power plant › Engine fuel and control › Turbine governor › Failure
- cause Not determined › Not determined › (general) › (general) › Unknown/Not determined
- cause Aircraft › Aircraft oper/perf/capability › Aircraft capability › (general) › Capability exceeded
Pilot
- Certificate: commercial pilot
- Ratings: single-engine land; instrument: airplane; rotorcraft: helicopter
- Flight time: 1,945 hours in all
- Last flight review: August 3, 2009
- Medical certificate: Class 2 (with waivers/limitations)
- Seat: rgt
- Injury: no injuries
Other crew
- Certificate: commercial pilot, private
- Ratings: single-engine land; rotorcraft: helicopter
- Flight time: 1,390 hours in all
- Last flight review: October 14, 2008
- Medical certificate: Class 3 (without waivers/limitations)
- Seat: left
- Injury: no injuries
The aircraft
- Airframe total time: 8,043 hours
- Last inspection: continuous airworthiness programme, August 27, 2009; 78 hours since
- Maximum gross weight: 3,200 lb
- Seats: 4
- Landing gear: fixed
- Engine: Rolls Royce 250 C20C (turboshaft); 0 hours total
The flight
- Departed from: OCF Ocala FL
- Destination: OCF Ocala FL
- Flight plan: none
- Runway 36, 7,467 ft by 150 ft
- A second pilot was aboard
Weather at the time
- Light: night
- Visibility: 10 statute miles
- Sky: clear
- Temperature: 81°F (27°C), dew point 70°F (21°C)
- Altimeter: 30.03 inHg
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Flight crew | 2 |
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.