# NTSB LAX87DVD04: Hiller UH-23-D, N61PC, Brentwood, CA, August 5, 1987

- Type: NTSB accident investigation
- Classification: Accident · No injuries · Final report
- Date: August 5, 1987, 06:30 local (13:30 UTC)
- Place: Brentwood, CA
- Coordinates: 37.869338, -121.680091 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=37.8693&lon=-121.6801&mi=10
- Phase of flight: [Maneuvering](https://openairdocs.org/ntsb-phases/450) (OpenAirDocs' grouping)
- Highest injury: No injuries
- Injuries: 1 uninjured
- Status: Completed, report February 24, 1989
- Report: Approved by Office Director
- NTSB case key (mKey): 25336
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=LAX87DVD04
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/25336/pdf
- Page: https://openairdocs.org/ntsb/LAX87DVD04

## Sequence of events

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

- Airframe/component/system failure/malfunction, maneuvering - aerial application
  - misc rotorcraft,tail boom - failure,partial (cause)
  - fuselage,attachment - separation (cause)
- Loss of control - in flight, maneuvering - aerial application
- In flight collision with terrain/water, descent - uncontrolled
  - object - tree(s) (contributing factor)

## Analysis

DURING AN AERIAL APPLICATION FLIGHT, THE TAIL BOOM WEIGHT SEPARATED AND CONTACTED THE TAIL ROTOR. THE PILOT LOST CONTROL OF THE AIRCRAFT AND COLLIDED WITH A TREE AND SUBSEQUENTLY THE TERRAIN. POST ACC INVEST REVEALED THAT THE 'PIP PINS' WHICH SECURE THE TAIL BOOM WEIGHT BROKE IN FLT ALLOWING MOVEMENT OF THE WEIGHT.

## Aircraft

- Registration: [N61PC](https://openairdocs.org/deregistered/N61PC-2013-08-20), registration cancelled 2013-08-20, S/N 1309, built 1962 (OpenAirDocs)
- Reported make and model: HILLER UH-23-D
- Registry model: [Hiller H-23D](https://openairdocs.org/model/hiller-h-23d) (registry code 4360120) (OpenAirDocs)
- Registry engine: [Lycoming VO-540 series](https://openairdocs.org/engine/lycoming-vo-540-series) (registry code 41534, reciprocating) (OpenAirDocs)
- Category: Helicopter
- Serial number: 1309
- Airframe hours: 2502
- Engines: LYCOMING O-540 305 horsepower reciprocating
- Damage: Substantial damage
- Flight: Aerial application, Part 137
- Registered owner: Doff W. Cooksey
- Airworthiness certificate: Special, Restricted (Special)
- Last inspection: Annual, February 12, 1987, 75 hours before

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 36; commercial; medical: class 2, valid medical--no waivers/lim.; seat: left; flight hours: 5,000 total, 4,900 in this make and model, 90 in the last 30 days, 4 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Day
- Lowest ceiling: none

## 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 19870805043249A](https://openairdocs.org/incident/19870805043249A), Aug 5, 1987: Hiller H23D, Brentwood, CA, Substantial damage. The helicopter impacted the ground during aerial application.

## Other investigations on N61PC (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 LAX00LA107](https://openairdocs.org/ntsb/LAX00LA107), Feb 21, 2000: Hiller H-12E (N61PC), Byron, CA, substantial damage. Probable cause: The pilot's inadequate visual lookout while maneuvering in proximity to wires. A contributing factor was the sun glare, which reduced the wire's conspicuity.

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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