Robinson R22 BETA accident near Del Valle, Texas, June 27, 2011
On June 27, 2011 at about 5:23 pm local time, a Robinson R22 BETA (helicopter), registered N7779M, was substantially damaged in an accident during enroute (cruise) near Del Valle, Texas. It was a personal flight under general aviation rules (Part 91). 1 person was killed. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
The divergence of the main rotor from its normal plane of rotation for reasons that cannot be determined because the pilot’s control inputs leading up to the event are unknown, resulting in mast bumping and main rotor blade separation.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- June 27, 2011 · about 5:23 pm local time
- Place
- Del Valle, Texas · map
- Type
- Accident
- Injuries
- 1 person was killed.
- Weather
- visual conditions (good weather)
- Aircraft
- Robinson R22 BETA · all R22 BETAs on the register
- Registration
- N7779M · no longer on the register · serial 1229
- Damage
- Substantial damage
- Flight
- Personal flight · general aviation rules (Part 91)
The NTSB's narrative final · quoted from the NTSB record
The helicopter was flying across a river when witnesses heard a loud "pop" or "bang" and saw something fall from the helicopter into the river. They heard the helicopter crash, saw smoke, and ran to the crash site. One main rotor blade was found approximately 780 feet from the wreckage. The other main rotor blade was found approximately 975 feet from the wreckage in the opposite direction. Both blades had separated from the main rotor hub at their coning hinges. All components of the helicopter were accounted for with the exception of portions of both coning bolts. The investigation was unable to locate the object observed falling from the helicopter or determine what it was. Examination of the rotor head components, including the recovered portions of the coning bolts, revealed fracture features consistent with overload failure and mechanical damage indicative of mast bumping (contact between the main rotor blades and the mast). The main rotor blade pitch links and attaching hardware displayed compression buckling and bending overload features consistent with an out-of-control main rotor that had diverged from its normal plane of rotation. The helicopter manufacturer reported that the damage signatures were consistent with both low-G mast bumping and low rotor rpm rotor stall. Low-G mast bumping is a phenomenon specific to two-bladed teetering rotor systems in which the rotor disc becomes unloaded, typically due to a cyclic pushover. Low rotor rpm rotor stall is a different phenomenon in which the main rotor blades experience an aerodynamic stall due to low rotor rpm caused either by the pilot raising the collective too much or by a loss of engine power followed by the pilot lowering the collective too slowly. Rotor blade stall can lead to mast bumping. The pilot’s control inputs leading up to the event are unknown, and, therefore, the reason for the main rotor divergence could not be determined.
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
- Mast bumping during enroute (cruise) defining event
- Aircraft structural failure during enroute (cruise)
- Collision with terrain or object (not controlled flight into terrain) during uncontrolled descent
The NTSB's findings
- cause Aircraft › Aircraft propeller/rotor › Main rotor system › Main rotor head system › Damaged/degraded
- cause Aircraft › Aircraft propeller/rotor › Main rotor system › Main rotor blade system › Failure
Pilot
- Certificate: private
- Ratings: multi-engine land; single-engine land; instrument: airplane; rotorcraft: helicopter
- Flight time: 220 in this make and model
- Last flight review: August 27, 2010
- Medical certificate: Class 2 (with waivers/limitations)
- Seat: rgt
- Injury: fatal
The aircraft
- Airframe total time: 2,295 hours
- Last inspection: annual inspection, December 30, 2010; 20 hours since
- Maximum gross weight: 1,370 lb
- Seats: 2
- Landing gear: fixed
- Engine: Lycoming O-320-B2C (piston); 0 hours total
- Fire on the ground
The flight
- Departed from: KT74 Taylor TX at 5:05 pm
- Destination: Luling TX
- Flight plan: none
Weather at the time
- Light: daylight
- Wind: from 190° at 12 knots, gusting 19
- Visibility: 10 statute miles
- Sky: scat at 3,600 ft
- Temperature: 93°F (34°C), dew point 72°F (22°C)
- Altimeter: 29.93 inHg
- Observation at 4:53 pm from AUS, 7 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.