# NTSB LAX83LA069: Hiller UH-12E, N4027D, Near Vacaville, CA, January 8, 1983

- Type: NTSB accident investigation
- Classification: Accident · No injuries · Limited investigation · Final report
- Date: January 7, 1983, 16:30 local (Jan 8, 1983, 00:30 UTC)
- Place: Near Vacaville, CA
- Coordinates: 38.410953, -122.009902 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=38.4110&lon=-122.0099&mi=10
- Phase of flight: [Initial climb](https://openairdocs.org/ntsb-phases/350) (OpenAirDocs' grouping)
- Highest injury: No injuries
- Injuries: 1 uninjured
- Status: Completed
- Report: Approved by Office Director
- NTSB case key (mKey): 23596
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=LAX83LA069
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/23596/pdf
- Page: https://openairdocs.org/ntsb/LAX83LA069

## Sequence of events

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

- In flight collision with object, takeoff - initial climb
  - object - wire,transmission (contributing factor)
  - compensation for wind conditions - misjudged, pilot in command (cause)
- Roll over, other
  - precautionary landing - performed, pilot in command (contributing factor)
  - unsuitable terrain or takeoff/landing/taxi area - selected, pilot in command (cause)
  - terrain condition - dirt bank/rising embankment (contributing factor)
  - terrain condition - soft (contributing factor)

## Analysis

THE AIRCRAFT COLLIDED WITH A TELEPHONE WIRE DURING TAKEOFF. THE PILOT MADE A PRECAUTIONARY LANDING ON THE SOFT BANK OF A LEVEE TO ASSESS THE DAMAGE AND LEFT THE ROTOR AT IDLE. THE LEVEE BANK GAVE WAY AND THE HELICOPTER SLID INTO THE DITCH WHERE THE ROTOR BLADES HIT THE GROUND. THE PILOT SAID HE SHOULD NOT HAVE WORKED SO CLOSE TO THE WIRES.

## Aircraft

- Registration: [N4027D](https://openairdocs.org/aircraft/N4027D), registered now, S/N 5072 (OpenAirDocs)
- Reported make and model: HILLER UH-12E
- Registry model: [Hiller UH-12E](https://openairdocs.org/model/hiller-uh-12e) (registry code 4360122) (OpenAirDocs)
- Category: Helicopter
- Serial number: 5072
- Airframe hours: 600
- Engines: LYCOMING VO-540-C2A 305 horsepower reciprocating
- Damage: Substantial damage
- Flight: Aerial application, Part 137
- Registered owner: Robert Porterfarm Air Flying I
- Airworthiness certificate: Special, Restricted (Special)
- Last inspection: 100 hour, March 20, 1982, 70 hours before

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 36; commercial; airplane ratings: single-engine land; medical: class 2, valid medical--no waivers/lim.; seat: right; flight hours: 6,080 total, 300 in this make and model, 5,700 as pilot in command, 60 in the last 90 days, 3 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Dusk
- Wind: calm
- Visibility: 3 statute miles
- Temperature: 50 °F

## 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 19830107000309A](https://openairdocs.org/incident/19830107000309A), Jan 7, 1983: Hiller UH12E, Vacaville, CA, Substantial damage. Rotor blades struck a powerline when helicopter lifted from a levee. Pilot landed ok but slid off into a ditch.

## Other investigations on N4027D (2)

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 LAX95LA318](https://openairdocs.org/ntsb/LAX95LA318), Sep 1, 1995: Hiller UH-12E (N4027D), Dos Palos, CA, substantial damage. Probable cause: the fatigue failure of the tail rotor tension torsion bar plates.
- [NTSB OAK79DVA30](https://openairdocs.org/ntsb/OAK79DVA30), Apr 27, 1979: Hiller UH-12E (N4027D), Gustine, CA, substantial damage

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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