# NTSB LAX91FA399: Piper PA-28-181, N8272Y, Cupertino, CA, September 21, 1991

- Type: NTSB accident investigation
- Classification: Accident · Fatal · Field investigation · Final report
- Date: September 20, 1991, 23:34 local (Sep 21, 1991, 06:34 UTC)
- Place: Cupertino, CA
- Coordinates: 37.299816, -122.089866 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=37.2998&lon=-122.0899&mi=10
- Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping)
- Highest injury: Fatal
- Injuries: 2 fatal
- Status: Completed, report January 22, 1993
- Report: Approved by Office Director
- NTSB case key (mKey): 27026
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=LAX91FA399
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/27026/pdf
- Page: https://openairdocs.org/ntsb/LAX91FA399

## Probable cause

THE PILOT'S FAILURE TO MAINTAIN THE PROPER ALTITUDE, HIS IMPROPER INFLIGHT DECISION TO ATTEMPT FLIGHT BELOW THE BASE OF AN OVERCAST LAYER OF CLOUDS TOWARD RISING MOUNTAINOUS TERRAIN AND THE FLIGHT'S INADVERTENT ENTRY INTO INSTRUMENT METEOROLOGICAL CONDITIONS. FACTORS WHICH CONTRIBUTED TO THE ACCIDENT WERE THE PILOT'S MISJUDGED WEATHER EVALUATION AND HIS IMPROPER VFR PROCEDURES.

## Sequence of events

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

- In flight collision with terrain/water, cruise - normal
  - light condition - bright night
  - weather condition - clouds
  - weather evaluation - misjudged, pilot in command (contributing factor)
  - in-flight planning/decision - improper, pilot in command (cause)
  - vfr flight into imc - inadvertent, pilot in command (cause)
  - vfr procedures - improper, pilot in command (contributing factor)
  - terrain condition - mountainous/hilly
  - proper altitude - not selected, pilot in command (cause)
  - emergency procedure - not performed, pilot in command

## Analysis

THE 229-HOUR INSTRUMENT RATED PRIVATE PILOT DEPARTED BAKERSFIELD FOR A FLIGHT HOME DURING BRIGHT NIGHTIME VFR CONDITIONS. APPROACHING HIS DESTINATION AIRPORT, SAN CARLOS, THE PILOT CONTACTED NAS MOFFETT AND RECEIVED PERMISSION TO TRANSIT ITS AIRSPACE. THE PILOT WAS TOLD TO REPORT OVER THE AIRPORT. AS THE PILOT APPROACHED THE AIRPORT HE LIKELY ENCOUNTERED A FORECAST OVERCAST LAYER OF CLOUDS HAVING BASES AT 1,000 FEET. THE PILOT MADE A 60 TO 70 DEGREE CHANGE OF COURSE AWAY FROM NAS MOFFETT AND PROBABLY ATTEMPTED TO FLY BENEATH THE CLOUDS WHILE OVER THE DENSELY POPULATED AND ILLUMINATED AREAS OF THE CITY. THE PILOT ENTERED THE BASE OF THE CLOUDS, CONTINUED FLYING UNTIL ENTERING A MOUNTAINOUS AREA AND LOST VISUAL REFERENCE TO THE CITY. SECONDS BEFORE IMPACT THE PILOT REQUESTED THE FREQUENCY FOR A NEARBY RADAR FACILITY. THE PILOT WAS FAMILIAR WITH THE AREA HAVING RECENTLY LEARNED TO FLY IN THE VICINITY.

## Aircraft

- Registration: [N8272Y](https://openairdocs.org/deregistered/N8272Y-1991-12-09), registration cancelled 1991-12-09, S/N 288190045 (OpenAirDocs)
- Reported make and model: PIPER PA-28-181
- Registry model: [Piper PA-28-181](https://openairdocs.org/model/piper-pa-28-181) (registry code 7102807) (OpenAirDocs)
- Category: Airplane
- Serial number: 28-8190045
- Engines: LYCOMING O-360-A4M 180 horsepower reciprocating
- Damage: Destroyed
- Flight: Personal, Part 91
- Operator: Golden Gate Aviation
- Last inspection: Unknown, January 2, 2000
- Departed: BFL, BAKERSFIELD, CA
- Destination: SQL, SAN CARLOS, CA
- Flight plan: IFR

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 32; private; airplane ratings: single-engine land; instrument ratings: airplane; medical: class 3, valid medical--no waivers/lim.; seat: left; toxicology performed; flight hours: 229 total, 179 in this make and model, 119 as pilot in command, 67 in the last 90 days, 21 in the last 30 days

## Weather

- Conditions: Instrument (IMC), Night/dark
- Wind: 30° at 2 knots
- Visibility: 7 statute miles
- Lowest ceiling: 1,000 ft overcast
- Temperature: 61 °F, dew point 54 °F
- Altimeter: 29.00 inHg
- Observed at: NUQ, 7 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 19910920042219A](https://openairdocs.org/incident/19910920042219A), Sep 20, 1991: Piper PA28181, Cupertino, CA, Destroyed, 2 fatal. Flew into mountain upslope at night trying to fly to base airport under a low ceiling. Prior ILS made to san jose.

## Other investigations on N8272Y (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 DEN86LA217](https://openairdocs.org/ntsb/DEN86LA217), Jul 30, 1986: Piper PA-28-181 (N8272Y), Monument Valley, UT, substantial 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.

---
OpenAirDocs.org is an independent research project of [Contrail Labs](https://contraillabs.com/). It is not affiliated with the FAA or the NTSB. Source documents are U.S. government works in the public domain.