NTSB Factual Report

On January 16, 2005, at 0955 Pacific standard time, a Cessna 150H, N22562, collided with trees during a forced landing following a loss of engine power about 1,600 feet north of the Pauma Valley Air Park, Pauma Valley, California. Rison Aviation was operating the privately registered airplane under the provisions of 14 CFR Part 91. The student pilot, the sole occupant, sustained minor injuries; the airplane sustained substantial damage. The pilot departed from Gillespie Field, El Cajon, California, at 0916, and was on a round robin flight with planned stops at the Hemet Airport, Hemet, California, and French Valley Airport, Temecula, California. The pilot planned to return to Gillespie Field. Visual meteorological conditions prevailed, and no flight plan had been filed.

According to the pilot, prior to departure, he leaned the mixture. He climbed the airplane to 6,500 feet mean sea level (msl) and did not change the mixture setting. During cruise flight at 6,500 feet msl, the tachometer read 2,700 revolutions per minute (rpm), the engine began sputtering and finally ceased operating approximately 30 seconds later. During the descent for a forced landing, the pilot attempted to restart the engine four times. While setting up to land on an airstrip, the pilot performed 360-degree turns to lose altitude. After coming out of the second turn, the airplane was too low to make the airstrip so the pilot landed the airplane in an orchard. Prior to his departure from Gillespie Field, the pilot performed a before-takeoff run-up with no anomalies noted.

Rescue personnel that responded to the accident scene reported 1/2 tank of fuel in the left wing and full fuel in the right wing.

The airplane recovery personnel recovered the airplane a few days following the accident and transported it to a storage facility located in Ramona, California. As the aircraft recovery personnel were draining fuel from the airplane, approximately 2 gallons of fuel were drained when they observed the fuel drainage to stop. Upon removing the fuel caps, the drain stream returned to full flow.

The Federal Aviation Administration (FAA) inspector was present for the engine test-run and venting system examination at Cruiseair Aviation, Inc., Ramona. Cruiseair Aviation, Inc., completed a written synopsis of the examinations. The engine was test-run using fuel recovered from the airplane. The engine started normally and was run-up to 900 rpm. Operation above this rpm was not possible due to the impact damage sustained to the propeller. The oil pressure was normal. The fuel vent line that extends from the bottom of the left fuel tank and the cross vent line between the right and left fuel tanks were tested using air flow; neither line was obstructed. The fuel caps were tested on a Cessna fuel tank and a vacuum suction was applied; neither fuel cap vented. The fuel caps were disassembled and examined. There was no evidence of blockage in the fuel cap venting system. Examination of the fuel caps did not reveal why they did not vent.

The last 100-hour inspection was completed on November 13, 2004. At the time of the accident, approximately 85 hours had accumulated on the airplane since the last inspection. According to the operator, the aviation maintenance technician (AMT) that performed the work completed it in accordance with the approved aircraft inspection manual. The inspection manual gives instructions for checking the vent lines; however, no instructions are given for the process involved with checking the fuel cap venting. The inspection manual states that the fuel caps and fuel vents are to be inspected every 100 hours of operation or at the annual inspection. It was noted, in part, in the inspection manual to, "Remember that a plugged vent line or bleed hole can cause either fuel starvation and collapsing of fuel tanks or the pressurization of tanks by fuel expansion."

A comparison of sampled weather data on a carburetor icing chart in the FAA publication, Tips on Winter Flying (FAA-P-8740-24), indicated that weather conditions were not condusive to carburetor icing.

NTSB Probable Cause

the loss of engine power due to an undetermined obstruction in the vent system for the fuel tanks and failure of the fuel caps to vent.