# NTSB LAX83FA362: Fairchild Hiller FH-1100, N450FH, Porterville, CA, July 28, 1983

- Type: NTSB accident investigation
- Classification: Accident · Fatal · Field investigation · Final report
- Date: July 28, 1983, 12:03 local (19:03 UTC)
- Place: Porterville, CA
- Coordinates: 35.959259, -118.919334 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=35.9593&lon=-118.9193&mi=10
- Phase of flight: [Maneuvering](https://openairdocs.org/ntsb-phases/450) (OpenAirDocs' grouping)
- Highest injury: Fatal
- Injuries: 2 fatal
- Status: Completed
- Report: Approved by Office Director
- NTSB case key (mKey): 23481
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=LAX83FA362
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/23481/pdf
- Page: https://openairdocs.org/ntsb/LAX83FA362

## Sequence of events

In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf).

- Loss of control - in flight, maneuvering
  - maneuver - performed, pilot in command
  - cyclic - improper use of, pilot in command (cause)
  - aircraft handling - not maintained, pilot in command (cause)
  - lack of recent experience in type of aircraft, pilot in command (contributing factor)
- Airframe/component/system failure/malfunction, maneuvering
  - rotor drive system,main rotor mast(drive shaft) - overload
  - rotor system - separation
- In flight collision with terrain/water, descent - uncontrolled

## Analysis

ON 7/27/83, MILD MAST BUMPING OCCURRED DURING A PUSHOVER MANEUVER WHILE A HILLER FH-1180 WAS ON A FLT TO CERTIFY NEW ROTOR BLADES. PRIOR TO THE INCIDENT, THE HELICOPTER WAS ACCELERATED TO 90 MPH. THIS WAS FOLLOWED BY A PULL-UP & DECELERATION TO 80 MPH, THEN THE PUSHOVER WAS INITIATED. THE HELICOPTER REPORTEDLY ROLLED SHARPLY TO THE RIGHT & PITCHEDNOSE DOWN WITH SOME YAW TO THE RIGHT. RECOVERY WAS MADE WITH LEFT CYCLIC; HOWEVER, DIRECTIONAL CONTROL WAS LOST BEFORE RECOVERY & MILD MAST BUMPING. ON 7/28/83, FH-1100, N450FH, A STANDARD PRODUCTION MODEL, WAS FLOWN TO EXPLORE THE PHENOMENON. AFTER 2 PUSHOVERS WITH INCREASING SEVERITY, IN WHICH CONTROL WAS RETAINED, THE PLT ATTEMPTED A REPETITION OF THE PREVIOUS DAY'S MANEUVER. WITNESSES OBSERVERVED THE HELICOPTER ROLL & YAW TO THE RIGHT & PITCH DOWN AS IT BEGAN TO BREAK UP, THEN BURN & CRASH. AN EXAM REVEALED THE MAIN ROTOR BLADES SEPARATED AFTER MAST BUMPING & MAST FAILURE OCCURRED. THERE WAS EVIDENCE THE PLT MIGHT NOT HAVE BEEN CURRENT IN TEETERING ROTOR SYSTEMS & RECOVERY FROM LOW G ROLLS.

## Aircraft

- Registration: [N450FH](https://openairdocs.org/deregistered/N450FH-1984-02-21), registration cancelled 1984-02-21, S/N 215, built 1970 (OpenAirDocs)
- Reported make and model: FAIRCHILD HILLER FH-1100
- Registry model: [Fairchild Hiller FH-1100](https://openairdocs.org/model/fairchild-hiller-fh-1100) (registry code 3376502) (OpenAirDocs)
- Category: Helicopter
- Serial number: 215
- Airframe hours: 5288
- Engines: ALLISON 250-C18 240 horsepower turbo shaft
- Damage: Destroyed
- Fire: Both
- Flight: Part 91
- Operator: Hiller Aviation
- Registered owner: Ernst And Whinney
- Airworthiness certificate: Standard, Normal
- Last inspection: Annual, March 16, 1983, 10 hours before
- Airport: PTV, Porterville Muni

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 62; flight instructor, commercial; airplane ratings: single-engine land, multi-engine land; instrument ratings: airplane, helicopter; medical: class 2, valid medical--w/ waivers/lim; seat: right; toxicology performed; flight hours: 14,546 total, 400 in this make and model

## Weather

- Conditions: Visual (VMC), Day
- Wind: 220° at 4 knots
- Visibility: 5 statute miles
- Lowest ceiling: none
- Altimeter: 30.00 inHg
- Observed at: VIS, 24 nm away

## FAA reports on this event (1)

The FAA's own accident and incident reports, matched to the aircraft by N-number and date (OpenAirDocs).

- [Accident 19830728035809A](https://openairdocs.org/incident/19830728035809A), Jul 28, 1983: Hiller FH1100, Porterville, CA, Destroyed, 1 fatal. Mast bumping. Main rotor separation, a fire and explosion occurred during a low g load factory test maneuver.

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.

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