# NTSB LAX93FA242: Piper PA-23-150, N522T, Diablo, CA, June 6, 1993

- Type: NTSB accident investigation
- Classification: Accident · Fatal · Field investigation · Final report
- Date: June 6, 1993, 11:50 local (18:50 UTC)
- Place: Diablo, CA
- Coordinates: 37.849376, -121.950614 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=37.8494&lon=-121.9506&mi=10
- Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping)
- Highest injury: Fatal
- Injuries: 2 fatal
- Status: Completed, report November 19, 1993
- Report: Approved by Office Director
- NTSB case key (mKey): 27832
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=LAX93FA242
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/27832/pdf
- Page: https://openairdocs.org/ntsb/LAX93FA242

## Probable cause

THE PILOT IN COMMAND'S CONTINUED FLIGHT INTO INSTRUMENT METEOROLOGICAL CONDITIONS, AND THE IMPROPER IN FLIGHT PLANNING AND DECISION MAKING BY THE PILOT.

## Sequence of events

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

- In flight encounter with weather, cruise
  - weather condition - fog
  - weather condition - low ceiling
- In flight collision with terrain/water, cruise
  - vfr flight into imc - attempted, pilot in command (cause)
  - in-flight planning/decision - improper, pilot in command (cause)
  - terrain condition - mountainous/hilly

## Analysis

THE AIRPLANE COLLIDED WITH MOUNTAINOUS TERRAIN IN A NEAR WINGS LEVEL ATTITUDE DURING INSTRUMENT METEOROLOGICAL CONDITIONS.  WITNESSES REPORTED NORMAL ENGINE SOUNDS WHEN THE AIRPLANE FLEW OVER THEIR LOCATION.  THERE WAS NO RECORD OF THE PILOT OBTAINING A WEATHER BRIEFING PRIOR TO HIS DEPARTURE.  THERE WERE NO MECHANICAL FAILURES OR MALFUNCTIONS FOUND DURING AN EXAM OF THE AIRCRAFT WRECKAGE.  BOTH PROPELLER'S SHOWED CHORDWISE SCRATCHES AND 'S' BENDING.

## Aircraft

- Registration: [N522T](https://openairdocs.org/deregistered/N522T-2013-08-15), registration cancelled 2013-08-15, S/N 23-1067, built 1957 (OpenAirDocs)
- Reported make and model: PIPER PA-23-150
- Registry model: [Piper PA-23-150](https://openairdocs.org/model/piper-pa-23-150) (registry code 7102303) (OpenAirDocs)
- Registry engine: [Lycoming 0-320 series](https://openairdocs.org/engine/lycoming-0-320-series) (registry code 41508, reciprocating) (OpenAirDocs)
- Category: Airplane
- Serial number: 23-1067
- Engines: LYCOMING O-320 150 horsepower reciprocating
- Damage: Destroyed
- Fire: On-Ground
- Flight: Personal, Part 91
- Operator: Norman E. Lamantia
- Registered owner: Norman E. Lamantia
- Airworthiness certificate: Standard, Normal
- Last inspection: Annual, March 4, 1993
- Departed: APC, NAPA, CA
- Destination: RHV, SAN JOSE, CA

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 59; commercial; airplane ratings: single-engine land, multi-engine land; instrument ratings: airplane; medical: class 2, valid medical--w/ waivers/lim; seat: left; toxicology performed; flight hours: 1,119 total, 986 as pilot in command, 18 in the last 90 days, 3 in the last 30 days

## Weather

- Conditions: Instrument (IMC), Day

## 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 19930606017039A](https://openairdocs.org/incident/19930606017039A), Jun 6, 1993: Piper PA23150, Diablo, CA, Destroyed, 2 fatal. Flew into vertical rock cliff on a mountainside in IMC in dense fog. No record weather briefing.

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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