# Accident 20080629841569A: Bell UH1B, Iliamna, AK, June 29, 2008

- Type: FAA accident report (Accident/Incident Data System), as reported
- Date: June 29, 2008, 22:30 local time
- Place: Iliamna, AK
- Airport: Iliamna
- Damage: Substantial damage
- Phase of flight: Final Approach
- Operating rules: Rotorcraft external load (Part 133)
- Operator: UPXC
- Location: 61.2706° N, 149.7898° W: From the FAA
- Nearby events: https://openairdocs.org/map.md?lat=61.2706&lon=-149.7898&mi=10
- Aircraft: N64RA, a cancelled registration (https://openairdocs.org/deregistered/N64RA-2022-03-05) (OpenAirDocs)
- Registry model: Richards Heavylift Helo UH-1B (registry code 118141G, https://openairdocs.org/model/richards-heavylift-helo-uh-1b) (OpenAirDocs)
- Registry engine: Amateur-built UNKNOWN ENG (registry code 99999, https://openairdocs.org/engine/amateur-built-unknown-eng) (OpenAirDocs)
- Reported make and model: BELL UH1B
- Reported engine: LYC T53L13B
- People aboard: 2
- Fatal injuries: 0
- Pilot flight hours: 30,000 total, 950 in this make and model, 180 in the last 90 days
- NTSB investigation: [NTSB ANC08LA083](https://openairdocs.org/ntsb/ANC08LA083) (OpenAirDocs)
- FAA source: FAA Aviation Safety Information Portal (https://asip.faa.gov/)
- Page: https://openairdocs.org/incident/20080629841569A

## Narrative

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

(-23) DURING A PRACTICE "AUTOROTATION" MANEUVER THE COLLECTIVE WAS LOWERED TO APPROXIMATELY 2/3 DOWN WHEN, THE HELICOPTER EXPERIENCED A SEVERE VERTICAL 1:1 VIBRATION.  INCREASING OR DECREASING POWER, OR INPUTTING OF CYCLIC ROLL OR PITCH, WOULD NOT DECREASE VIBRATION.  THE VIBRATION SUBSIDED WITH THE COLLECTIVE "BOTTOMED-OUT".  DURING THE FLARE, WHEN THE COLLECTIVE WAS RAISED FOR POWER, THE VIBRATION RETURNED WHICH RESULTED IN A HARD LANDING.  A PRELIMINARY INSPECTION REVEALED WARPED TAIL BOOM, DENTS IN THE LEADING EDGE OF THE TAIL ROTOR BLADES, BENT AFT SKID CROSS TUBE, CRACKS IN THE MAIN ROTOR TRANSMISSION SUPPORT, AND A 1/4 INCH SEPARATION BETWEEN MAST RETAINING PLATE AND THE UPPER TRANSMISSION CASE.  A REVIEW OF THE MAINTENANCE RECORDS PROVIDED DOES NOT INDICATE A PROBABLE CAUSE FOR THE VIBRATION.  THE POST ACCIDENT INSPECTION BY AN OUTSIDE COMPANY INDICATES, SEVERAL CONTROL BEARINGS WORN WHICH CUMMUTATIVITY MAY HAVE INDUCED A VERTICAL VIBRATION.  THE INTERVIEWS WITH THE DIRECTOR OF MAINTENANCE AND THE PILOT, INDICATE NO HISTORY OF MAINTENANCE PROBLEMS SINCE THIS AIRCRAFT WAS RELEASED FROM A HEAVY MAINTENANCE VISIT APPROXIMATELY 30 HOURS PRIOR TO THE ACCIDENT.

## 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 ANC08LA083](https://openairdocs.org/ntsb/ANC08LA083), Jun 30, 2008: Bell UH-1B (N64RA), Iliamna, AK, substantial damage. Probable cause: The failure of company maintenance personnel to ensure the helicopter was properly maintained, resulting in a severe in-flight vibration due to collective bounce. Contributing to the accident was…

## Other reports on N64RA (1)

Matched to the same aircraft by N-number and date.

- [Accident 20190308001019A](https://openairdocs.org/incident/20190308001019A), Mar 8, 2019: Richards Heavylift Helo Inc UH-1B (N64RA), Forks, WA, Substantial damage, 1 fatal. While conducting 14CFR part 133 external load, logging operations, the helicopter collided with mountainous terrain. The pilot who was the sole person onboard…

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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