# NTSB LAX99LA234: Piper PA-28-181, N3477Q, San Luis Obispo, CA, July 6, 1999 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: July 6, 1999, 08:15 local (15:15 UTC) - Place: San Luis Obispo, CA - Coordinates: 35.250896, -120.620475 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=35.2509&lon=-120.6205&mi=10 - Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping) - Highest injury: No injuries - Injuries: 2 uninjured - Status: Completed, report April 6, 2001 - Report: Approved by Office Director - NTSB case key (mKey): 46747 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=LAX99LA234 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/46747/pdf - Page: https://openairdocs.org/ntsb/LAX99LA234 ## 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 In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - Loss of engine power(total) - mech failure/malf, climb - to cruise - fuel system,carburetor - fire (contributing factor) - induction air ducting - deteriorated (contributing factor) - hot start - not identified, unknown (contributing factor) - fuel system,carburetor - contamination,other than water (cause) - Forced landing, descent - emergency - weather condition - low ceiling - On ground/water encounter with terrain/water, landing - 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](https://openairdocs.org/deregistered/N3477Q-2012-09-12), registration cancelled 2012-09-12, S/N 28-7790456, built 1977 (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) - Registry engine: [Lycoming O&VO-360 series](https://openairdocs.org/engine/lycoming-o-vo-360-series) (registry code 41514, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: 28-7790456 - Airframe hours: 7781 - Engines: 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 ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 47; 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 (OpenAirDocs). - [Accident 19990706042679A](https://openairdocs.org/incident/19990706042679A), Jul 6, 1999: Piper PA28181, San Luis Obispo, CA, Substantial damage. (.4)On July 6, 1999, about 0815 hours PDT, a Piper PA-28-181, N3477Q, operated by cal coast flyers, inc. was substantially damaged during a forced landing near… 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.