Bell 214ST accident near Avalon, Texas, August 7, 2012
On August 7, 2012 at about 1:45 pm local time, a Bell 214ST (helicopter), registered N409SB, was substantially damaged in an accident during maneuvering near Avalon, Texas. It was a flight test under general aviation rules (Part 91). No one was hurt; 2 people were on board or involved. The weather was visual conditions (good weather).
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The NTSB's probable cause their words, unchanged
Maintenance personnel’s failure to properly torque the retaining nut and install the cotter pin that secured the helicopter’s tail rotor counterweight bellcrank. Contributing to the accident was the lack of detailed maintenance records that documented previous maintenance actions.
Source: NTSB aviation accident database, copy made October 4, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- August 7, 2012 · about 1:45 pm local time
- Place
- Avalon, Texas · map
- Type
- Accident
- Injuries
- No one was hurt; 2 people were on board or involved.
- Weather
- visual conditions (good weather)
- Aircraft
- Bell 214ST · all 214STs on the register
- Registration
- N409SB · no longer on the register · serial 28199
- Damage
- Substantial damage
- Flight
- Flight test · general aviation rules (Part 91)
The NTSB's narrative final · quoted from the NTSB record
The helicopter was on its third test flight when the tail rotor 90-degree gearbox broke in two and separated from the helicopter. The crew conducted an autorotation to a field, and the helicopter came to rest on its side. Examination of the helicopter and components revealed that one of the tail rotor's two counterweight bellcranks and associated hardware were missing. Impact marks consistent with a counterweight bellcrank were found at the base of its associated tail rotor blade and on the aft right side of the helicopter. The remaining counterweight bellcrank was in place; however, the cotter pin for the castellated nut was missing. A review of the aircraft maintenance records revealed that the tail rotor assembly had been removed and reinstalled after the installation of test instrumentation. The maintenance records lacked specific details on whether the unit and its components were previously handled as a subassembly or as individual components when the tail rotor assembly was initially removed. Because the records did not indicate whether the unit should be handled as individual parts, the tail rotor was reinstalled as a complete subassembly, meaning that individual components, such as the nut and cotter pin, were not individually inspected before or after reinstallation on the helicopter. Reinstalling the tail rotor assembly in this manner led to the counterweight bellcrank retaining nut not being properly torqued and secured with a cotter pin.
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
- Flight control sys malf/fail during maneuvering defining event
- Part(s) separation from AC during maneuvering
- Off-field or emergency landing during landing
- Roll over during landing (flare/touchdown)
The NTSB's findings
- cause Aircraft › Aircraft propeller/rotor › Tail rotor drive system › Tail rotor drive shaft › Failure
- cause Personnel issues › Task performance › Maintenance › Installation › Maintenance personnel
- factor Organizational issues › Support/oversight/monitoring › Documentation/record keeping › Maintenance records › Operator
Pilot
- Certificate: flight instructor, commercial pilot
- Ratings: multi-engine land; single-engine land; instructor: airplane multi-engine; instructor: airplane single-engine; instructor: helicopter; instructor: instrument airplane; instructor: instrument helicopter; instructor: powered-lift; instrument: airplane; instrument: helicopter; instrument: powered-lift; rotorcraft: helicopter; rotorcraft: powered-lift
- Flight time: 6,597 hours in all; 2.7 in this make and model; 18.7 in the last 90 days; 5.3 in the last 30 days; 3,918 as pilot in command
- Medical certificate: Class 2 (with waivers/limitations)
- Seat: rgt
- Injury: no injuries
Co-pilot
- Certificate: airline transport pilot, flight instructor, commercial pilot
- Ratings: multi-engine land; single-engine land; instructor: helicopter; instructor: instrument helicopter; instrument: airplane; instrument: helicopter; rotorcraft: helicopter
- Flight time: 3,100 hours in all; 2.7 in this make and model; 35 in the last 90 days; 12 in the last 30 days; 2,600 as pilot in command
- Last flight review: April 15, 2012
- Medical certificate: Class 2 (without waivers/limitations)
- Seat: left
- Injury: no injuries
The aircraft
- Seats: 18
- Landing gear: fixed
- Engine 1: General Electric CT7-2A (turboshaft); 0 hours total
- Engine 2: General Electric CT7-2A (turboshaft); 0 hours total
- Operator: Bell Helicopter Textron INC
The flight
- Departed from: KGKY Arlington Muni TX at 1:15 pm
- Destination: KGKY Arlington Muni TX
- A second pilot was aboard
Weather at the time
- Light: daylight
- Visibility: 10 statute miles
- Sky: clear
- Temperature: 84°F (29°C), dew point 66°F (19°C)
- Altimeter: 29.96 inHg
- Observation at 2:53 pm from KGKY
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Flig | 2 |
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 CEN12LA525.