# NTSB LAX95LA075: Kaman HH43, N321WN, Glendale, AZ, January 10, 1995

- Type: NTSB accident investigation
- Classification: Accident · No injuries · Limited investigation · Final report
- Date: January 9, 1995, 17:40 local (Jan 10, 1995, 00:40 UTC)
- Place: Glendale, AZ
- Coordinates: 33.510852, -112.359481 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=33.5109&lon=-112.3595&mi=10
- Phase of flight: [Maneuvering](https://openairdocs.org/ntsb-phases/450) (OpenAirDocs' grouping)
- Highest injury: No injuries
- Injuries: 1 uninjured
- Status: Completed, report June 19, 1995
- Report: Approved by Office Director
- NTSB case key (mKey): 29012
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=LAX95LA075
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/29012/pdf
- Page: https://openairdocs.org/ntsb/LAX95LA075

## Probable cause

The pilot's failure to maintain an adequate visual lookout to avoid a collision with a tree during an aerial application swath run.

## Sequence of events

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

- In flight collision with object, maneuvering - aerial application
  - object - tree(s)
  - visual lookout - inadequate, pilot in command (cause)
  - rotor system,main rotor blade - vibration (contributing factor)
  - misc rotorcraft,tail boom - cracked (contributing factor)
- Forced landing, emergency descent/landing
  - terrain condition - wet

## Analysis

DURING A CLEANUP RUN OVER A FIELD, THE AIRCRAFT COLLIDED WITH SOME TREE BRANCHES WITH THE RIGHT MAIN ROTOR BLADE WHICH RESULTED IN A SEVERE VIBRATION AND SUBSTANTIAL DAMAGE TO THE TAILBOOM.  THE PILOT MADE A SUCCESSFUL FORCED LANDING INTO A MUDDY FIELD.  THE TREE BRANCHES EXTENDED 15 TO 20 FEET INTO THE FIELD.  THERE WERE NO RESTRICTIONS OR OBSCURATION TO VISIBILITY REPORTED BY THE PILOT.

## Factual narrative

On January 9, 1995, at 1740 mountain standard time, a Kaman HH- 43F helicopter, N321WN, collided with a tree and crashed into a field during a Part 137 aerial application flight near Glendale, Arizona.  Visual meteorological conditions existed at the time.  The aircraft was substantially damaged and the pilot was not injured.  The aircraft departed from a private helicopter pad near Tolleson, Arizona, at 1730.

According to the pilot, he had completed spraying the field and was cleaning up the ends.  On the last pass, he did not see the bare tree branches that protruded 15 to 20 feet into the field until it was too late.  He stated that the right main rotor blade struck the branches which tore off the control flap to the rotor blade causing a severe vibration.  The pilot immediately landed in a muddy field and shut down the engine.  Examination of the helicopter by the pilot revealed that the tail booms were cracked and broken by the severe vibrations.  There was no fire, fuel, or chemical spill.

## Aircraft

- Registration: [N321WN](https://openairdocs.org/deregistered/N321WN-2012-05-24), registration cancelled 2012-05-24, S/N 25, built 1959 (OpenAirDocs)
- Reported make and model: KAMAN HH43
- Registry model: [Kaman HH-43F](https://openairdocs.org/model/kaman-hh-43f) (registry code 4800708) (OpenAirDocs)
- Registry engine: [Lycoming T-53 series](https://openairdocs.org/engine/lycoming-t-53-series) (registry code 41587, turbo-prop) (OpenAirDocs)
- Category: Helicopter
- Serial number: 25
- Airframe hours: 4933
- Engines: LYCOMING T-53-11C 1100 horsepower turbo shaft
- Damage: Substantial damage
- Flight: Aerial application, Part 137
- Operator: Freeway Aviation
- Registered owner: Pyramid Oil Co.
- Airworthiness certificate: Standard, Normal
- Last inspection: Annual, September 15, 1994, 50 hours before
- Departed: TOLLESON, AZ

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 60; flight instructor, commercial; airplane ratings: multi-engine land, single-engine land; instrument ratings: airplane; medical: class 3, valid medical--w/ waivers/lim; seat: right; flight hours: 11,100 total, 952 in this make and model, 9,200 as pilot in command, 8 in the last 90 days, 2 in the last 30 days, 2 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Dusk
- Wind: 180° at 2 knots
- Visibility: 10 statute miles
- Lowest ceiling: none
- Temperature: 64 °F
- Altimeter: 29.00 inHg

## 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 19950109001209A](https://openairdocs.org/incident/19950109001209A), Jan 9, 1995: Kaman HH43F, Glendale, AZ, Substantial damage. Rotors struck dead tree branches on last low pass to spray field edges. Damaged rotor blade. Vibration 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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