Continental Copters INC. 47G2 accident near Lohn, Texas, January 1, 2012
On January 1, 2012 at about 8:00 pm local time, a Continental Copters INC. 47G2 (helicopter), registered N9021R, was substantially damaged in an accident during maneuvering (low-alt flying) near Lohn, Texas. It was an aerial observation flight under general aviation rules (Part 91). 2 people were seriously injured. The weather was visual conditions (good weather).
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The NTSB's probable cause their words, unchanged
The improper installation of the tail rotor gearbox by maintenance personnel, which led to accelerated wear of the ring and pinion gears, resulting in the loss of tail rotor effectiveness and subsequent forced landing.
Source: NTSB aviation accident database, copy made October 4, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- January 1, 2012 · about 8:00 pm local time
- Place
- Lohn, Texas · map
- Type
- Accident
- Injuries
- 2 people were seriously injured.
- Weather
- visual conditions (good weather)
- Aircraft
- Continental Copters INC. 47G2
- Registration
- N9021R · registry record · serial CCI-165
- Damage
- Substantial damage
- Flight
- Aerial observation flight · general aviation rules (Part 91)
The NTSB's narrative final · quoted from the NTSB record
The pilot performed a preflight inspection of the helicopter to include checking the tail rotor oil level through its sight glass. He had flown the helicopter for more than an hour when the tail yawed to the left, slowly at first then rapidly. The pilot “cut” the throttle, flew the helicopter “to the ground as fast as possible,”and impacted terrain. A postaccident examination of the wreckage revealed that the tail rotor gearbox did not operate when it was rotated. A teardown revealed that the interior surfaces of the gearbox were covered with a black oily substance consistent with residual lubricating oil contaminated with liberated metal particles. The oil level sight glass exhibited no discoloration or other hindrance to normal oil level detection in service. Examination of the ring and pinion gears revealed that the teeth on the pinion gear were deformed and worn almost down to the tooth root in some locations. Wear was observed on the top land and drive faces of the ring gear. Wear patterns were noted on the coast faces of the ring and pinion gear teeth. The observation of wear on the coast faces of the gear teeth is most probably an indication that the spacing between the gears was too tight as a result of improper alignment during installation, causing accelerated wear. A logbook entry showed that the helicopter’s last annual inspection was completed about 6 months before the accident during which the tail rotor gearbox was overhauled and installed.
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
- Flight control sys malf/fail during maneuvering (low-alt flying) defining event
- Loss of tail rotor effectiveness during emergency descent
- Collision with terrain or object (not controlled flight into terrain) during uncontrolled descent
The NTSB's findings
- cause Aircraft › Aircraft propeller/rotor › Tail rotor drive system › Tail rotor gearbox › Fatigue/wear/corrosion
- cause Aircraft › Aircraft propeller/rotor › Tail rotor drive system › Tail rotor gearbox › Incorrect service/maintenance
- cause Personnel issues › Task performance › Maintenance › Repair › Maintenance personnel
Pilot
- Certificate: commercial pilot
- Ratings: single-engine land; instrument: airplane; rotorcraft: helicopter
- Flight time: 14,000 hours in all; 35 in the last 90 days; 14,000 as pilot in command
- Last flight review: May 3, 2011
- Medical certificate: Class 2 (without waivers/limitations)
- Seat: left
- Injury: serious injuries
The aircraft
- Airframe total time: 9,057 hours
- Last inspection: annual inspection, July 13, 2011; 68 hours since
- Maximum gross weight: 2,350 lb
- Seats: 2
- Landing gear: fixed
- Engine: Lycoming VO-435-A1D (piston); 0 hours total
- Operator: Sky Horse Helicopters INC
The flight
- Departed from: Lohn TX at 7:00 pm
- Destination: Lohn TX
- Flight plan: none
Weather at the time
- Light: daylight
- Wind: from 340° at 12 knots
- Visibility: 10 statute miles
- Sky: clear
- Temperature: 55°F (13°C), dew point 21°F (-6°C)
- Altimeter: 30.52 inHg
- Observation at 9:35 pm from BBD, 12 miles away
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Flig | 1 | |||
| Passengers | 1 |
Other NTSB records under N9021R the same tail number, which may have belonged to a different aircraft at the time
About this page
Everything above comes from the NTSB's public accident database: the narrative, probable cause and findings are the NTSB's own words, and the coded tables behind its report (pilot, aircraft, flight, weather, injuries, sequence of events) are written out in plain English. Pilots' ages, home towns and medical details are left out on purpose. The docket at the NTSB holds the report as a PDF and the investigation's photographs and documents. This site never names pilots, passengers or anyone else involved. A preliminary report describes what is known soon after the event and can change; the final report, with the probable cause, usually follows one to two years later and this page is refreshed when it does. Case number CEN12LA120.