# NTSB LAX90DUA01: Homebuilt JP-350-1, N350JP, Torrance, CA, June 28, 1990

- Type: NTSB accident investigation
- Classification: Accident · Minor injuries · Final report
- Date: June 28, 1990, 15:18 local (23:18 UTC)
- Place: Torrance, CA
- Coordinates: 33.799087, -118.35083 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=33.7991&lon=-118.3508&mi=10
- Phase of flight: [Initial climb](https://openairdocs.org/ntsb-phases/350) (OpenAirDocs' grouping)
- Highest injury: Minor injuries
- Injuries: 1 minor
- Status: Completed, report December 8, 1992
- Report: Approved by Office Director
- NTSB case key (mKey): 26526
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=LAX90DUA01
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/26526/pdf
- Page: https://openairdocs.org/ntsb/LAX90DUA01

## Probable cause

THE AIRCRAFT COLLISION WITH THE GROUND AFTER THE PILOT EXPERIENCED A LOSS OF ENGINE THRUST DUE TO PROPELLER OVERSPEED CONDITION. CONTRIBUTING TO THE ACCIDENT WAS THE PILOT'S IMPROPER SERVICING OF THE PROPELLER HUB THAT ALLOWED THE OVERSPEED TO OCCUR.

## Sequence of events

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

- Loss of engine power(partial) - mech failure/malf, takeoff - initial climb
  - propeller system/accessories,blade - not installed (contributing factor)
  - maintenance,balancing - not performed, pilot in command (cause)
  - propeller system/accessories,counterweight - pressure too low (contributing factor)
  - maintenance,pressurizing - inadequate, pilot in command (cause)
- In flight collision with terrain/water, descent - emergency

## Analysis

THE PILOT OF THE HOMEBUILT SERVICED THE PROPELLER HUB WITH 120 PSI PRIOR TO DEPARTURE. AFTER TAKEOFF HE LOST CONTROL OF THE PROPELLER AND THE ENGINE LOST THRUST. EXAMINATION OF THE PROPELLER ASSEMBLY REVEALED NO EVIDENCE OF A PRE-IMPACT MALFUNCTION. THE PROPELLER BLADES HAD BEEN SHORTENED AND THE PROPELLER OVERSPEED OCCURRED BECASUE THE BLADES WERE NOT COUNTERWEIGHTED. HARTZELL STATED THE 120 PSI CHARGE IN THE HUB WAS INSUFFICIENT TO COUNTERACT THE AERODYNAMIC TWISTING MOMENTS AND PREVENT THE OVERSPEED.

## Aircraft

- Registration: [N350JP](https://openairdocs.org/deregistered/N350JP-2013-05-09), registration cancelled 2013-05-09, S/N 88350-01 (OpenAirDocs)
- Reported make and model: HOMEBUILT JP-350-1
- Registry model: [American Air Racing/Parker JP 350-1](https://openairdocs.org/model/american-air-racing-parker-jp-350-1) (registry code 0561697) (OpenAirDocs)
- Registry engine: [Lycoming IO-540 series](https://openairdocs.org/engine/lycoming-io-540-series) (registry code 41530, reciprocating) (OpenAirDocs)
- Category: Airplane, amateur-built
- Serial number: 88350-1
- Engines: LYCOMING L-1174-61 350 horsepower reciprocating
- Damage: Substantial damage
- Flight: Personal, Part 91
- Registered owner: John G. Parker
- Airworthiness certificate: Special, Experimental (Special)
- Airport: TOA, Torrance Muni, runway 29R, 5,000 × 150 ft, asphalt

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 51; airline transport; airplane ratings: multi-engine land, single-engine land; instrument ratings: airplane; medical: class 1, valid medical--w/ waivers/lim; seat: center; flight hours: 20,000 total, 36 in this make and model, 200 in the last 90 days, 62 in the last 30 days

## Weather

- Conditions: Visual (VMC), Day
- Wind: 300° at 14 knots
- Visibility: 9 statute miles
- Lowest ceiling: none
- Temperature: 75 °F, dew point -0 °F
- Altimeter: 29.00 inHg
- Observed at: TOA

## 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 19900628022749A](https://openairdocs.org/incident/19900628022749A), Jun 28, 1990: Amtr JP3501, Torrance, CA, Substantial damage. Prop overspeed on takeoff. Feathered and turned back but impacted hard on airport. Prop had lacked counterweights.

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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