LAX99LA234

NTSB accident investigation · Piper PA-28-181 · San Luis Obispo, CA · July 6, 1999

Accident · No injuriesLimited investigationFinal report
Date
July 6, 1999, 08:15 local (15:15 UTC)
Place
San Luis Obispo, CA
Injuries
2 uninjured
Damage
Substantial damage
Phase of flight
Enroute
Aircraft
N3477QPiper PA-28-181
Weather
Visual (VMC) · Day
Status
Completed · report April 6, 2001
Report
Approved by Office Director
FAA report
19990706042679A
Case key
46747

From the NTSB’s public API. By law, NTSB reports can’t be used as evidence in lawsuits over the accident.

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Probable cause

A loss of engine power due to contamination of the induction system and the carburetor throat. Factors in the accident were a prior undetected carburetor fire, which caused a deterioration in the air duct material.

Sequence of events

NTSB’s coding before 2008: each occurrence and phase of flight, and the causes and factors under it. The codes are defined in NTSB’s coding manual.

Loss of engine power(total) - mech failure/malfClimb - to cruise
Fuel system,carburetor - fireFactor
Induction air ducting - deterioratedFactor
Hot start - not identifiedUnknownFactor
Fuel system,carburetor - contamination,other than waterCause
Forced landingDescent - emergency
Weather condition - low ceiling
On ground/water encounter with terrain/waterLanding - roll
Terrain condition - rough/uneven

Analysis

The flight instructor and student obtained an instrument departure clearance to climb to VFR on top for a cross-country flight. After reaching VFR on top, the engine rpm decreased to about 1,800 and then to 1,500. Following unsuccessful attempts to restore power, the instructor descended through the stratus cloud deck and became VFR about 700-800 feet msl. The power level was insufficient to reach the airport and he landed in an open field. Examination of the carburetor revealed a fibrous material inside the throat similar to the lining found inside the intake duct. The duct had evidence of a prior carburetor fire, which had caused a deterioration of the duct. The last maintenance inspection on this rental aircraft was 50 hours prior to the accident.

Factual narrative

On July 6, 1999, about 0815 hours Pacific daylight time, a Piper PA-28-181, N3477Q, operated by Cal Coast Flyers, Inc., was substantially damaged during a forced landing near San Luis Obispo, California. The forced landing was precipitated by a loss of engine power during the climb to cruise phase. Neither the certified flight instructor nor the student pilot was injured. Instrument meteorological conditions prevailed at both the departure airport and the accident site. The instructor had received an instrument clearance for an IFR climb to VFR conditions on top. The cross-country instructional flight, conducted under the provisions of 14 CFR Part 91, departed at 0800 and was en route to Santa Monica, California.

After reaching VFR on top, about 1,800 feet msl, the instructor reported that he applied carburetor heat to the engine. At that point, the engine revolutions decreased to 1,800 and then to 1,500 rpm. The instructor was unsuccessful in restoring full engine power, and, the power output was insufficient to maintain altitude. He then descended through the stratus cloud deck, broke out at 700-800 feet msl, and landed in an open field. During the landing roll, the aircraft collided with ground obstructions.

Examination of the engine by an Federal Aviation Administration inspector from the San Jose Flight Standards District Office revealed a fibrous material contaminating the inside of the carburetor throat. Further examination of the induction system revealed a burned and torn carburetor inlet hose.

The last maintenance inspection of the engine on this rental aircraft occurred 50 hours prior to the accident.

Aircraft

Registration
N3477Q
Reported as
Piper PA-28-181
Category
Airplane
Serial number
28-7790456
Airframe hours
7,781
Engine
Lycoming O-360-A4M, 180 horsepower, reciprocating
Damage
Substantial damage
Flight
Instructional · Part 91
Registered owner
Cal Coast Flyers, Inc.
Airworthiness certificate
Standard, Normal
Last inspection
100 hour · April 19, 1999 · 50 hours before
Departed
SBP
Destination
SMO · Santa Monica, CA

Matched to the registry by N-number and the event date; the registry’s history has gaps, so older matches can be wrong. Compare the reported make and model.

Flight crew

As NTSB recorded them. NTSB leaves out names.

Role
Pilot
Age
47
Certificate
Commercial
Airplane ratings
Multi-engine land, Single-engine land
Instrument ratings
Airplane
Medical
Class 2, Valid Medical--no waivers/lim.
Seat
Left
Flight hours
3,050 total · 150 in this make and model · 2,920 as pilot in command · 126 in the last 90 days · 35 in the last 30 days

Weather

Conditions
Visual (VMC) · Day
Wind
Calm
Visibility
4 statute miles
Lowest ceiling
600 ft overcast
Temperature
64 °F

FAA reports on this event · 1

The FAA’s own accident and incident reports, matched to the aircraft by N-number and date.