Aviation Accident Summaries

Aviation Accident Summary FTW97LA359

PECOS, TX, USA

Aircraft #1

N82ND

Shutt MARQUART MA-5

Analysis

Two hours 3 minutes after refueling, the engine lost power. During the forced landing, the airplane drifted (winds gusting to 30 mph) across a runway (4,000 ft remained behind a taxiing aircraft), landed between runways, and struck a berm. During the previous flight of 2 hrs, there were no discrepancies and the fuel burn was 10 gph (usable fuel 27 gallons). When the pilot took 'his dipstick and dipped his fuel tank, the stick came out dry.' Subsequently, 3 or 4 ounces of fuel was drained from the fuel sump. The pilot examined the engine (without notifying the IIC) and reported finding the carburetor metering control lever assembly loose with a vertical travel from 1/3 to 1/2 inch, the mixture control lever was off the mixture control metering valve assembly by 1/3 inch, and the mixture control lock wire installed backwards. These components were not preserved for examination by the IIC. The manufacturer representative reported that some of the part numbers submitted by the pilot were incorrect for the carburetor. He further stated that the loose components 'could allow a little enrichment at the carburetor; however, the main jet of the carburetor meters the fuel to the engine.'

Factual Information

On September 7, 1997, at 1600 central daylight time, a Shutt Marquart MA-5 experimental airplane, N82ND, registered to and operated by a private individual, was substantially damaged during a forced landing following a loss of engine power at Pecos Municipal Airport, Pecos, Texas. The commercial pilot and the pilot rated passenger were not injured. Visual meteorological conditions prevailed and a flight plan was not filed for the Title 14 CFR Part 91 personal flight. The flight originated from Gillespie County Airport, Fredericksburg, Texas, approximately 1400. The pilot further reported that he had planned a route from Ellington Field Airport, Houston, Texas, to San Diego, California, utilizing two hour legs. The pilot reported that he performed a run-up before departing for Fredericksburg and noticed an excessive "mag[neto] drop." The aircraft was examined at the airport and a spark plug for the #2 cylinder was replaced. After the pilot performed a run-up and no discrepancies were found, the flight departed for Gillespie County Airport. The pilot also reported that the fuel system is a single tank (27.5 gallons total, 0.5 unusable). As per the Operator's Manual for the Textron Lycoming O-360-A4A engine, the engine should consume 9.0 to 9.5 gallons per hour (gph) at a power setting of 2,350 to 2,400 RPM. During the flight from Houston to Fredericksburg, the fuel consumtion indicated approximately 10 gph. The fueling facility at Gillespie County Airport is self serve. During the refueling of his airplane, the pilot noticed that the fuel passes through a 2 gallon size filter and then through the fueling pump. The meter reading at the filter was 23 gallons and the reading at the pump was 26 gallons. The pilot took the 23 gallons as the total fuel used from Houston to Fredericksburg. After 2 hours and 3 minutes, at an altitude of 1,000 feet AGL, during the pattern entry from the southeast of Pecos Municipal Airport, the engine lost power. The pilot attempted to land on runway 14; however, a non radio equipped aircraft was back taxiing runway 14. The pilot landed the airplane to the south, between two intersecting runways. During the landing roll the airplane contacted a one foot high berm, the main landing gear collapsed, the propeller struck the ground, and the airplane came to rest perpendicular to runway 09-27. The airport manager reported the winds were from the east at 10 knots gusting to 15 knots. Upon responding to the site, the airport manager noted that there was a "wet stain on the asphalt under the engine cowling as you would find when a pilot sumps his tank and dumps it onto the asphalt." The airport manager further stated that the pilot took "his dipstick and dipped his fuel tank, the stick came out dry." A few days later the airport manager drained 3 or 4 ounces of fuel from the fuel sump. An inspection of the aircraft, performed by a mechanic, revealed that the main spar of the right lower wing and landing gear assemblies sustained structural damage. The propeller and lower cowling were also damaged. During a telephone interview, conducted by the investigator-in-charge (IIC), and on the enclosed statement, a witness/pilot, who had landed his airplane on runway 9 and taxied on runway 32 and turned off on the taxiway, observed the airplane at 500 to 600 feet agl with the propeller stopped. The winds were from the east between 20 and 30 mph and the landing airplane drifted to the side of the runway into mesquite bushes. The witness taxied his aircraft to the site and talked to the pilot. He recalled the pilot stating that "the engine had been running rough, trying to quit for about 10 miles." When the witness observed the pilot check the fuel quantity, fuel "barely showed on the dipstick." After the aircraft was recovered to a hangar at the airport, the witness and the airport manager drained a few ounces of fuel from the airplane. The airplane was issued a conditional release for recovery for locked security and further investigation by the Safety Board. The owner conducted an examination of the engine and had the aircraft repaired prior to coordination with the Safety Board. The pilot reported that upon his examination of the engine, it was discovered that the mixture control lever assembly (part number 155-580) on the carburetor (Marvel-Schebler model MA 4-5) was loose and had a vertical travel from 1/3 to 1/2 inch. The mixture control lever assembly had moved off the mixture control metering valve assembly (part number 242-514) by 1/3 inch. The mixture control lock wire (part number 66-18) was installed backwards. A mechanic recorded in the maintenance records part number 66-18 was "installed upside down. This allowed the mixture control metering valve to have excessive vertical movement." The original components were not preserved by the owner for examination by the Safety Board. During a telephone interview, conducted by the IIC, a representative from Precision Airmotive Corporation reported that some of the part numbers submitted by the pilot are not applicable for the MA 4-5 carburetor. The representative further stated that the loose components "could allow a little fuel enrichment at the carburetor; however, the main jet of the carburetor meters the fuel to the engine." The aircraft's original airworthiness certificate was issued March 1, 1983, and the 25 hours of test flights was completed by May 11, 1983. A new carburetor box was installed in August 1989. In April, 1992, the airplane was disassembled for a paint change, reassembled, rigged, and test flown. The last conditional inspection was completed on August 16, 1997. A review of the maintenance records by the IIC did not reveal any maintenance discrepancies that would contribute to a loss of engine power. The reason for the engine's excessive fuel consumption could not be determined.

Probable Cause and Findings

The pilot's inadequate compensation for the crosswind during a forced landing following a loss of engine power due to fuel exhaustion for an undetermined reason. Factors were the gusty winds and rough/uneven terrain.

 

Source: NTSB Aviation Accident Database

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