# Accident 19990601006239A: Robsin R22MARINER, Glenallen, AK, June 1, 1999

- Type: FAA accident report (Accident/Incident Data System), as reported
- Date: June 1, 1999, 18:00 local time
- Place: Glenallen, AK
- Damage: Substantial damage
- Phase of flight: To Vertical (Helicopter Only)
- Operating rules: Air taxi and commuter (Part 135)
- Operator: OHQC
- Location: 62.0995° N, 145.5293° W: From the FAA, an estimate near the named town, within about 3 miles
- Nearby events: https://openairdocs.org/map.md?lat=62.0995&lon=-145.5293&mi=10
- Aircraft: N1929T, a cancelled registration (https://openairdocs.org/deregistered/N1929T-2000-05-05) (OpenAirDocs)
- Registry model: Robinson Helicopter R22 MARINER (registry code 7640115, https://openairdocs.org/model/robinson-helicopter-r22-mariner) (OpenAirDocs)
- Reported make and model: ROBSIN R22MARINER
- Reported engine: LYC O320B2C
- People aboard: 2
- Fatal injuries: 0
- Pilot flight hours: 2,373 total, 1,806 in this make and model
- NTSB investigation: [NTSB ANC99LA068](https://openairdocs.org/ntsb/ANC99LA068) (OpenAirDocs)
- FAA source: FAA Aviation Safety Information Portal (https://asip.faa.gov/)
- Page: https://openairdocs.org/incident/19990601006239A

## Narrative

As the FAA filed it, in capitals; the FAA replaces private details with ^PRIVACY DATA OMITTED^.

CRASHED ON TAKEOFF. OTHER CIRCUMSTANCE UNKNOWN. (-23) THE AIRMAN PICKED THE HELICOPTER INTO A HOVER AND POINTED THE SHIP INTO THE LIGHT AND VARIABLE WIND. AFTER A CYCLIC TURN TO THE LEFT AND PREPARING TO EXIT DOWNHILL. THE WIND SHIFTED TO A TAIL WIND, AND THE SURROUNDING TERRAIN ALSO CAUSED A DOWN DRAFT. THE AIRMAN APPLIED MORE POWER, AND THE LOW RPM HORN SOUNDED. AT THAT POINT THE PILOT STATED THAT HE WAS COMMITTED TO A TAKEOFF AND THAT ANOTHER DOWN DRAFT CAUSED THE HELICOPTERS PERFORMANCE TO DETERIORATE. WITH THE COMBINATION OF LOW ROTOR RPM, 4200 FOOT MSL TAKEOFF ELEVATION, A DOWN DRAFT, ALDER BUSHES CREATING DRAG, THE HELICOPTER STRUCK THE LEFT SKID AND ROLLED ON IT'S SIDE STRIKING THE MAIN ROTOR BLADE ON THE HILLSIDE. THE PILOT AND PASSENGER EXITED THE SHIP WITHOUT ANY INJURY.      (.4) THE CERTIFICATED COMMERCIAL HELICOPTER PILOT REPORTED THAT DURING A NORTHERLY DEPARTURE FROM ATOP A 4,200 FEET MSL MOUNTAIN, THE ROTOR RPM DROPPED, AND THE LOW ROTOR WARNING HORN SOUNDED. HE SAID THAT IN AN ATTEMPT TO REGAIN ROTOR RPM AND ARREST THE DECENT, HE ROLLED THE THROTTLE TO THE HIGH POSITION, INCREASED COLLECTIVE PITCH, AND LOWERED THE NOSE TO GAIN AIRSPEED.                            HE SAID THAT THE ROTOR RPM CONTINUED TO DECAY, THE HELICOPTER IMPACTED UNEVEN TERRAIN, AND ROLLED OVER. THE PILOT STATED: 'I JUST GOT INTO A DOWNDRAFT ON TAKEOFF.' HE ADDED THAT THERE WERE NO PREACCIDENT MECHANICAL ANOMALIES WITH THE HELICOPTER. THE HELICOPTER SUSTAINED SUBSTANTIAL DAMAGE TO THE ROTOR SYSTEM, AND FUSELAGE.

## The NTSB's investigation of this event (1)

From the NTSB's public API. Aircraft are matched to registry aircraft by N-number and event date, checked against the reported serial number, make and model; the registry's history has gaps, so older matches can be wrong. Compare the reported make and model.

- [NTSB ANC99LA068](https://openairdocs.org/ntsb/ANC99LA068), Jun 2, 1999: Robinson R22 (N1929T), Glennallen, AK, substantial damage. Probable cause: The pilot's failure to maintain rotor RPM during takeoff. Factors associated with the accident were a downdraft, and uneven terrain.

From the FAA Accident/Incident Data System. Reports are matched to registry aircraft by N-number and event date, checked against the reported make and model; the registry's history has gaps, so older matches can be wrong. Compare the reported make and model. For accidents, the NTSB's own investigation is the fuller record.

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