Aviation Accident Summaries

Aviation Accident Summary FTW99LA069

NEMO, TX, USA

Aircraft #1

N152PA

Cessna 150H

Analysis

During a go-around on the third attempted landing following a partial loss of engine power, the airplane struck fence posts and barbed wire fence at the end of the airstrip. The engine continued to run when the pilot pumped the throttle; however, during the approach over a pecan orchard, he 'elected to keep a higher airspeed.' On the 3rd pass, he decided to land the airplane; however, at the 'last minute tried for another go-around.' A witness observed the airplane climb, stall, and descend to the ground. The fuel tank cap on the left fuel tank was the un-vented type. The wing tank vent line and the right fuel cap vent were obstructed and air would not flow through the line or the right fuel cap vent. The obstruction appeared to be dirt. With the tanks vented, the engine was started and operated at low RPM. No mechanical anomalies were found that would preclude the engine operating and producing power.

Factual Information

On January 25, 1999, at 1530 central standard time, a Cessna 150H tailwheel equipped airplane, N152PA, sustained substantial damage when it struck metal fence posts during a go-around on the third attempted landing following a partial loss of engine power near Nemo, Texas. The aircraft was owned and operated by the private pilot under 14 Code of Federal Regulations (CFR) Part 91. The private pilot, sole occupant of the airplane, received serious injuries. Visual meteorological conditions prevailed for the local personal flight and a flight plan was not filed. The flight departed the owner's private ranch grass airstrip several minutes prior to the accident. Local authorities and the FAA inspector responding to the site found the airplane resting nose down in a gravel pit approximately 1/4 mile beyond the fence bordering the 1,700 foot private airstrip. Paint transfer was observed on the fence in the area where it had been repaired prior to the arrival of the FAA inspector. The engine was separated from the airframe and the left horizontal stabilizer, cockpit, and empennage sustained structural damage. A witness at the gravel pit observed the pilot perform a touch and go at the private grass airstrip. He then observed the airplane fly around for another touch and go landing. The "airplane touched down, slowed, and then went straight up about 75 to 100 feet in the air, stalled, and descended to the ground tail section first." This witness responded to the accident site and aided the pilot until local authorities arrived at the scene. During personal interviews, conducted by the investigator-in-charge (IIC), and on the Pilot/Operator Aircraft Accident Report (NTSB Form 6120.1/2), the pilot stated that after takeoff, the flight proceeded to the east of the airport at 1,500 feet agl. When the engine started to lose power, the pilot turned on the fuel boost pump, pumped the throttle, and returned for landing. The engine continued to run as long as the pilot turned on the boost pump and pumped the throttle. During the straight in approach over a pecan orchard and a high line, the pilot overshot the field and performed a go-around. As the pilot continued to pump the throttle, he could not control the airspeed, and the pilot "elected to keep a higher airspeed." On the 3rd pass, the pilot decided to try and keep the airplane on the ground; however, at the "last minute [the pilot] tried for another go-around, but [the] aircraft didn't clear the barbed wire fence" at the end of the airstrip. On January 27, 1999, the FAA inspector and the aircraft representative examined the airplane at the site (32 degrees 18.81 North; 097 degrees 43.47 west). Skid marks were observed through the grass at the departure end of the runway and the airplane came to rest 950 feet beyond the fence. Flaps were extended 30 degrees. Physical evidence indicated that the propeller, exhaust system, the left flap, and the right horizontal stabilizer struck the fence. Portions of the barbed wire fence were found attached at the right horizontal stabilizer. One propeller blade was bent aft with chordwise scoring. Fuel was found in the gascolator. The cockpit throttle and mixture controls were found in the full forward position. When the propeller was rotated, compression was noted within the engine and the magneto coupling rotated. Flight control continuity was confirmed to the rudder and the elevators. On March 9, 1999, the airplane was examined by the IIC and the engine representative. Flight control continuity was again confirmed. The fuel tank cap on the left fuel tank was found to be the "un-vented type." The wing tank vent line was obstructed and would not allow air passage. The left fuel tank vent line was removed and air pressure would not flow through the line. A wire pushed into the vent line reached the blockage at about the midpoint of the line. The right fuel cap vent was also found to be obstructed and would not allow air passage. The right fuel cap was disassembled and the obstruction appeared to be dirt. The pilot/operator stated that that there were many "dirt dobbers" in the area and he could not keep them away from the airplane. After the fuel vent line and the right fuel cap were removed and fuel was added to the right fuel tank, the 150 horsepower Lycoming engine was started three times and operated at low RPM. Fuel dripped out of the carburetor after each engine shut down. The carburetor was removed and disassembled. No pre-existing engine or carburetor discrepancies were noted and the examination did not reveal any evidence that the engine was not capable of operating and producing power at the time of the accident. A review of the maintenance records by the IIC revealed that the last annual inspection was performed on June 22, 1998. The engine had operated 2.95 hours since that last annual inspection. Historic modifications of the airplane included the following: conversion to the tailwheel configuration, addition of an electric fuel boost pump, and the use of automotive gasoline. On the Pilot/Operator Aircraft Accident Report (NTSB Form 6120.1/2) and in the FAA records it was revealed that the 69 year old private pilot did not hold a current medical certificate. His last medical certificate had been issued on July 15, 1991.

Probable Cause and Findings

A partial loss of engine power due to the obstructed fuel vent line and fuel cap vent.

 

Source: NTSB Aviation Accident Database

Get all the details on your iPhone or iPad with:

Aviation Accidents App

In-Depth Access to Aviation Accident Reports