# Accident 20180724014579A: Bell - Hagglund UH-1H, Oakdale, CA, July 24, 2018

- Type: FAA accident report (Accident/Incident Data System), as reported
- Date: July 24, 2018, 17:30 local time
- Place: Oakdale, CA
- Airport: Oakdale Municipal
- Damage: Substantial damage
- Phase of flight: Landing: Touchdown
- Operating rules: General operating rules (Part 91)
- Operator: X66L
- Location: 37.7983° N, 120.7222° W: From the FAA
- Nearby events: https://openairdocs.org/map.md?lat=37.7983&lon=-120.7222&mi=10
- Aircraft: N107CH, registered now (https://openairdocs.org/aircraft/N107CH) (OpenAirDocs)
- Registry model: Bell UH-1H (registry code 1181407, https://openairdocs.org/model/bell-uh-1h) (OpenAirDocs)
- Registry engine: Lycoming T53-L-13 (registry code 41551, https://openairdocs.org/engine/lycoming-t53-l-13) (OpenAirDocs)
- Reported make and model: BELL - HAGGLUND UH-1H
- Reported engine: LYCOMING T53-L-703
- People aboard: 2
- Fatal injuries: 0
- Other injuries: 1
- Pilot certificates: Commercial pilot
- Pilot flight hours: 11,000 total
- NTSB investigation: [NTSB WPR18LA206](https://openairdocs.org/ntsb/WPR18LA206) (OpenAirDocs)
- FAA source: FAA Aviation Safety Information Portal (https://asip.faa.gov/)
- Page: https://openairdocs.org/incident/20180724014579A

## Narrative

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

THE ACCIDENT OCCURRED WHILE REPOSITIONING TO A NEW AERIAL FIRE FIGHTING ASSIGNMENT FOR THE STATE FIRE AGENCY UNDER A CWN CONTRACT ORDER. IN CRUISE FLIGHT AT APPROXIMATELY 500 AGL, THE PILOT AND HIS PASSENGER REPORTEDLY SUDDENLY HEARD AN UNUSUAL NOISE, WHICH GREW LOUDER. HOWEVER, NO UNUSUAL OR INCREASE IN NORMAL VIBRATION WAS REPORTED. THE PILOT INITIALLY DIVERTED TO THE NEAREST AIRPORT O27, BUT DUE TO THE INCREASE IN NOISE, ELECTED TO MAKE AN IMMEDIATE OFF AIRPORT  PRECAUTIONARY POWER ON LANDING INTO THE WIND ON A GRASSY HILLTOP NEAR A RANCH HOUSE & HIGHWAY. AN  EMT PASSING ON THE HIGHWAY, WHO WITNESSED AND IMMEDIATELY RESPONDED TO THE SCEENE, STATED THAT THE AIRCRAFT CIRCLED THE LZ ONCE THEN TOUCHED DOWN AND SUDDENLY POPPED BACK UP IN THE AIR 50 FT, SPUN AT LEAST  A 360 DEGREE CLOCKWISE ROTATION OUT OF CONTROL AND THEN  CAME DOWN HARD ON ITS NOSE, RAISING A DEBRIS / DUST CLOUD. THE NEXT DAY, THE PILOT WAS OVERHEARD STATING TO A FIRE AGENCY INVESTIGATOR, THAT ON APPROACH, WHEN HE INITIALLY CAME TO A HEIGHT OF APROX 5 FT, THE AIRCRAFT MADE AN UNCOMMANDED CLIMB AND THEN NOSED OVER, AND FIGHTING THE CYCLIC, THEN CONTACTING THE GROUND HARD.

THE PILOT WAS SEATED IN THE LEFT PILOTS SEAT, AN STC APPROVED PIC SEAT, AND SUFFERED A SUPERFICIAL LACERATION TO HIS CHIN.

A NON ESENTIAL PASSENGER, SEATED IN THE RIGHT PILOTS SEAT, WAS SERIOUSLY INJURED, AND AIRLIFTED FROM THE SCENE, WITH FRACTURED T12 CERVICAL VERTEBRAE.

THE EVIDENCE AT THE ACCIDENT SITE SHOWED THAT THE NOSE FIRST, AND THEN TAIL SKID, HAD CONTACTED THE GROUND HARD. THE CROSS TUBES OF THE LANDING GEAR WERE SPREAD AND COLLAPSED AFTWARD FROM THE SKID TUBES. THE ROTOR BLADES HAD CONTACTED THE GROUND, CHOPPING THE BATTERY HATCH IN HALF AND THE UPPER WSPS WAS COMPLETELY KNOCKED OFF. ONE BLADE SHOWED THE DRAG BRACE PULLED FROM THE TRAILING EDGE AND THE BLADE MOSTLY DISINTEGRATED, AND THE OTHER BLADE SHOWED THE PITCH HORN PULLED FROM ITS GRIP, WITH THE BLADE MOSTLY INTACT EXCEPT FOR DAMAGE TO THE TIP SECTION.  THE  TRANSMISSION WAS TORN FROM ITS MOUNTING AND TILTED TO THE RIGHT FRONT CORNER OF THE AIRCRAFT AT A 45 DEGREE ANGLE.

DETAILED EXAMINATION OF THE WRECKAGE REVEALED THAT THE SWASH PLATE SUPPORT HAD BROKEN FREE FROM THE GIMBAL RING, THUS DISCONNECTING THE MAIN ROTOR FLIGHT CONTROLS. THE FRACTURE SURFACES SHOWED POLISHING, AND THE COLLECTIVE SLEEVE SHOWED SIGNIFICANT BATTERING BY THE GYMBAL RING BOLT HEADS, AT 4 EQUALLY SPACED ABRADED AREAS WHERE THEY HAD BEEN CONTACTING THE COLLECTIVE SLEEVE IN FLIGHT FOR SOME TIME PROIR TO THE BLADE TUDDEN STOPPAGE IMPACT AT THE ACCIDENT SCENE.

## 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 WPR18LA206](https://openairdocs.org/ntsb/WPR18LA206), Jul 24, 2018: Bell UH 1H (N107CH), Oakdale, CA, substantial damage. Probable cause: The pilot's loss of control during a precautionary landing following an abnormal noise in-flight, the source of which could not be determined.

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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