# NTSB LAX92LA056: Piper PA22-150, N3170Z, Palo Alto, CA, December 1, 1991

- Type: NTSB accident investigation
- Classification: Accident · No injuries · Limited investigation · Final report
- Date: December 1, 1991, 15:55 local (23:55 UTC)
- Place: Palo Alto, CA
- Coordinates: 37.3404, -121.879005 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=37.3404&lon=-121.8790&mi=10
- Phase of flight: [Landing](https://openairdocs.org/ntsb-phases/550) (OpenAirDocs' grouping)
- Highest injury: No injuries
- Injuries: 4 uninjured
- Status: Completed, report May 3, 1993
- Report: Approved by Office Director
- NTSB case key (mKey): 27512
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=LAX92LA056
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/27512/pdf
- Page: https://openairdocs.org/ntsb/LAX92LA056

## Probable cause

THE PILOT'S FAILURE TO MAINTAIN DIRECTIONAL CONTROL DURING THE LANDING ROLLOUT.

## Sequence of events

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

- Loss of control - on ground/water, landing - roll
  - directional control - not maintained, pilot in command (cause)
- On ground/water encounter with terrain/water, landing - roll
  - ground loop/swerve - inadvertent, pilot in command

## Analysis

THE PILOT REPORTED THAT HIS AIRPLANE HAD BEEN MODIFIED BY THE INSTALLATION OF A TAIL WHEEL ASSEMBLY.  ACCORDING TO THE PILOT, HE LANDED ON RUNWAY 12 AND DURING ROLLOUT LOST DIRECTIONAL CONTROL.  THEREAFTER, THE AIRPLANE GROUND LOOPED.  AT THE TIME THE WIND WAS FROM 120 DEGREES AT 5 KNOTS. DURING THE POST-ACCIDENT EXAMINATION OF THE AIRPLANE NO EVIDENCE WAS FOUND OF ANY MECHANICAL MALFUNCTIONS.  THE PILOT REPORTED HAVING 600 HOURS OF TAIL DRAGGER FLIGHT TIME.

## Aircraft

- Registration: [N3170Z](https://openairdocs.org/aircraft/N3170Z), registered now, S/N 22-7122, built 1959 (OpenAirDocs)
- Reported make and model: PIPER PA22-150
- Registry model: [Piper PA-22-150](https://openairdocs.org/model/piper-pa-22-150) (registry code 7102210) (OpenAirDocs)
- Registry engine: [Lycoming 0-320 series](https://openairdocs.org/engine/lycoming-0-320-series) (registry code 41508, reciprocating) (OpenAirDocs)
- Category: Airplane
- Serial number: 22-7122
- Airframe hours: 2707
- Engines: LYCOMING O-320 150 horsepower reciprocating
- Damage: Substantial damage
- Flight: Personal, Part 91
- Operator: James Ham
- Registered owner: James Ham
- Airworthiness certificate: Standard, Normal
- Last inspection: Annual, October 25, 1991, 24 hours before
- Departed: BFL, BAKERSFIELD, CA
- Flight plan: VFR
- Airport: PAO, Palo Alto, runway 12, 2,500 × 65 ft, asphalt

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 48; private; airplane ratings: single-engine land; instrument ratings: airplane; medical: class 3, valid medical--w/ waivers/lim; seat: left; flight hours: 1,162 total, 45 in this make and model, 1,048 as pilot in command, 16 in the last 90 days, 15 in the last 30 days, 7 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Day
- Wind: 120° at 5 knots
- Visibility: 5 statute miles
- Lowest ceiling: 2,000 ft broken
- Temperature: 61 °F, dew point 36 °F
- Altimeter: 30.00 inHg
- Observed at: PAO, 1 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 19911201053959A](https://openairdocs.org/incident/19911201053959A), Dec 1, 1991: Piper STCPA22, Palo Alto, CA, Substantial damage. Lost directional control landing. Ground looped. PA22150 modified to a tail wheel version.

## Other investigations on N3170Z (2)

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 WPR26FA109](https://openairdocs.org/ntsb/WPR26FA109), Feb 28, 2026: Piper PA-22-150 (N3170Z), Oroville, CA, destroyed, 1 fatal, investigation ongoing
- [NTSB LAX01LA185](https://openairdocs.org/ntsb/LAX01LA185), May 18, 2001: Piper PA-22-150 (N3170Z), Concord, CA, substantial damage. Probable cause: The pilot's inadequate compensation for wind conditions, resulting in a loss of directional control and the inadvertent ground loop.

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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