# NTSB LAX88DUA01: Hernandez Thorp T-18, N1394A, Palos Verdes, CA, April 23, 1988

- Type: NTSB accident investigation
- Classification: Accident · Fatal · Final report
- Date: April 23, 1988, 15:00 local (22:00 UTC)
- Place: Palos Verdes, CA
- Coordinates: 33.770179, -118.339912 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=33.7702&lon=-118.3399&mi=10
- Phase of flight: [Maneuvering](https://openairdocs.org/ntsb-phases/450) (OpenAirDocs' grouping)
- Highest injury: Fatal
- Injuries: 2 fatal
- Status: Completed, report July 21, 1989
- Report: Approved by Office Director
- NTSB case key (mKey): 25713
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=LAX88DUA01
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/25713/pdf
- Page: https://openairdocs.org/ntsb/LAX88DUA01

## Sequence of events

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

- Loss of control - in flight, maneuvering
  - reason for occurrence undetermined (cause)
- In flight collision with terrain/water, descent
  - terrain condition - water,rough

## Analysis

THE PILOT WAS DEMONSTRATING THE ACFT FOR THE PASSENGER FOR A POSSIBLE SALE.  THEY WERE PART OF A FLIGHT OF TWO OVER THE PACIFIC OCEAN.  THE OWNER OF THE AIRCRAFT BEING DEMONSTRATED WAS IN THE SECOND AIRCRAFT.  THE PILOT OF THE DEMO ACFT RADIOED TO THE SECOND ACFT THAT HE WAS GOING TO LET THE PASSENGER FLY, WHO WAS A COMM PILOT. THE ACFT INITIALLY BEGAN MAKING TIGHT TURNS BUT THEN TURNED AWAY FROM EACH OTHER. THE PLT OF THE SECOND ACFT DID NOT SEE THE DEMO ACFT AGAIN. A GROUND WITNESS REPORTED SEEING AN ACFT DIVING STRAIGHT TOWARDS THE WATER WITH NO ROTATION. A SEARCH BY THE SECOND ACFT REVEALED NOTHING. ACFT DEBRIS BELONGING TO THE DEMO ACFT WAS LATER FOUND ON THE BEACH AND EXHIBITED EXTREME ACCORDIAN SIGNATURES.

## Aircraft

- Registration: N1394A (not matched to a registry record)
- Reported make and model: HERNANDEZ THORP T-18
- Category: Airplane, amateur-built
- Serial number: T-18-143
- Airframe hours: 214
- Engines: LYCOMING O-320-E3D 160 horsepower reciprocating
- Damage: Destroyed
- Flight: Personal, Part 91
- Registered owner: Hernandez, John M
- Airworthiness certificate: Special, Experimental (Special)
- Last inspection: Annual, May 21, 1987, 14 hours before
- Departed: CPM, COMPTON, CA
- Destination: CPM

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 47; private; airplane ratings: single-engine land; medical: class 3, valid medical--w/ waivers/lim; seat: left; flight hours: 706 total, 127 in this make and model, 617 as pilot in command, 50 in the last 90 days, 3 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Day
- Wind: 270° at 15 knots
- Visibility: 25 statute miles
- Lowest ceiling: 2,000 ft broken
- Temperature: 57 °F
- Altimeter: 30.00 inHg
- Observed at: TOA, 13 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 19880423010069A](https://openairdocs.org/incident/19880423010069A), Apr 23, 1988: Amtrth THORPT18, Rancho Palos Ve, CA, Destroyed, 2 fatal. The homebuilt crashed in the ocean. Last observed in tight turn. Possible airframe overstress. Not recovered.

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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