# NTSB LAX92LA143: Cessna 172E, N5417T, Yucapia, CA, March 16, 1992

- Type: NTSB accident investigation
- Classification: Accident · Serious injuries · Limited investigation · Final report
- Date: March 15, 1992, 17:30 local (Mar 16, 1992, 01:30 UTC)
- Place: Yucapia, CA
- Coordinates: 34.039836, -117.01094 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=34.0398&lon=-117.0109&mi=10
- Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping)
- Highest injury: Serious injuries
- Injuries: 2 serious, 1 minor
- Status: Completed, report August 13, 1993
- Report: Approved by Office Director
- NTSB case key (mKey): 27576
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=LAX92LA143
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/27576/pdf
- Page: https://openairdocs.org/ntsb/LAX92LA143

## Probable cause

THE PARTIAL LOSS OF POWER MOST LIKELY RELATED TO THE POOR QUALITY OF AIRCRAFT MAINTENANCE. A FACTOR IN THE ACCIDENT WAS THE LACK OF SUITABLE TERRAIN FOR A FORCED LANDING.

## Sequence of events

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

- Loss of engine power, cruise
  - maintenance - inadequate, company/operator management (cause)
  - maintenance,overhaul,major - not performed, company/operator management (cause)
- Forced landing, descent - emergency
- In flight collision with terrain/water, descent - emergency
  - terrain condition - mountainous/hilly (contributing factor)
  - terrain condition - none suitable (contributing factor)
  - stall/mush - intentional, pilot in command

## Analysis

ALL 3 OCCUPANTS OF THE AIRCRAFT ARE PILOTS AND USAF OFFICERS. THEY SAID THAT AFTER TAKEOFF THEY WERE FLYING OVER A CANYON AREA ENROUTE TO A LOCAL PRACTICE AREA. ONCE OVER THE CANYON AREA AT 4,500 FT, THE PILOTS NOTICED THAT THE ENGINE WAS BEGINNING TO RUN SLIGHTLY ROUGH WITH A PERCEPTIBLE AND STEADY DECREASE IN RPM'S. THE RPM'S EVENTUALLY DECREASED TO 1,800 AND ALL ATTEMPTS TO CORRECT THE POWER LOSS WERE UNSUCCESSFUL. THE AIRCRAFT WAS UNABLE TO MAINTAIN LEVEL FLIGHT AND HAD DESCENDED BELOW THE TOPS OF THE SURROUNDING RIDGES. THE PILOTS STATED THAT THE ONLY VIABLE OPTION OPEN TO THEM WAS TO CONTACT THE HILLSIDE IN A CONTROLLED MANNER. THE AIRCRAFT WAS STALLED INTO THE THICK BRUSH COVERED HILLSIDE. CRASH SITE INACCESSIBILITY PRECLUDED DETERMINATION OF THE FUEL SYSTEM CONTINUITY OR FUEL SUPPLY QUALITY. THE CARBURETOR, GASCOLATOR AND IGNITION LEADS WERE DESTROYED IN THE CRASH. DETAILED EXAMINATION OF THE ENGINE REVEALED HEAVY SOOTING OF THE #1 TOP SPARK PLUG AND MODERATE EROSION AND GAS BLOW-BY OF THE PISTONS. COMPRESSION TESTS DURING THE LAST 100 HOUR INSPECTION SHOWED 3 CYLINDERS BELOW 60 PSI. THE LAST MAJOR OVERHAUL OF THE ENGINE WAS 25 YEARS AND 2,221 HOURS PRIOR TO THE ACCIDENT. THE ENGINE MANUFACTURER RECOMMENDS A MAJOR OVERHAUL EVERY 2,000 HOURS OR FIVE YEARS.

## Aircraft

- Registration: [N5417T](https://openairdocs.org/deregistered/N5417T-1993-05-04), registration cancelled 1993-05-04, S/N 17251317 (OpenAirDocs)
- Reported make and model: CESSNA 172E
- Registry model: [Cessna 172E](https://openairdocs.org/model/cessna-172e) (registry code 2072412) (OpenAirDocs)
- Category: Airplane
- Serial number: 17251317
- Airframe hours: 3276
- Engines: CONTINENTAL O-300-D 145 horsepower reciprocating
- Damage: Substantial damage
- Flight: Personal, Part 91
- Operator: Skyways Flight Training, Inc.
- Registered owner: David W. Lawson
- Airworthiness certificate: Standard, Normal
- Last inspection: 100 hour, December 19, 1991, 43 hours before
- Departed: L12, REDLANDS, CA

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 25; military, commercial; airplane ratings: multi-engine land, single-engine land; instrument ratings: airplane; medical: class 3, valid medical--no waivers/lim.; seat: left; flight hours: 305 total, 7 in this make and model, 230 as pilot in command, 10 in the last 90 days, 4 in the last 30 days, 1 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Day
- Wind: 240° at 2 knots
- Visibility: 7 statute miles
- Lowest ceiling: none
- Temperature: 64 °F, dew point 46 °F
- Altimeter: 29.00 inHg

## 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 19920315006429A](https://openairdocs.org/incident/19920315006429A), Mar 15, 1992: Cessna 172E, Yucapia, CA, Substantial damage. Engine gradually lost power. Unable to clear canyon. Impacted upslope. Cylinders low compression. Engine over tbo.

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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