ERA09LA516

NTSB accident investigation · Siai-Marchetti F.260 · Atlanta, GA · September 4, 2009

Accident · Minor injuriesLimited investigationFinal report
Date
September 4, 2009, 13:30 local (17:30 UTC)
Place
Atlanta, GA
Injuries
2 minor
Damage
Substantial damage
Phase of flight
Initial climb
Aircraft
N517PSiai-Marchetti F.260
Defining event
Initial climb: Loss of engine power (total)
Weather
Visual (VMC) · Day
Status
Completed · report January 7, 2011
Report
Approved by Office Director
NTSB office
Eastern Region Aviation
Parties
FAA/FSDO
FAA report
20090904049209A
Case key
74710

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

On this page

Probable cause

A total loss of engine power due to a fuel system air leak as a result of a deteriorated O-ring seal in the fuel shut-off cock. Contributing to the accident was the exceedance of the suggested overhaul schedule for the fuel shut-off cock.

Findings · 2

NTSB’s coded findings. Those marked are part of the probable cause; the rest are factors or other findings. Under each, the cases with the same finding.

Fuel system: fuel selector/shutoff valveAircraft › Aircraft systems · Fatigue/wear/corrosionSiai-Marchetti F.260: 1 caseAll aircraft: 176 casesProbable cause
Fuel system: fuel selector/shutoff valveAircraft › Aircraft systems · Not serviced/maintainedSiai-Marchetti F.260: 1 caseAll aircraft: 176 casesProbable cause

Sequence of events

The events NTSB coded, in order, by phase of flight. The defining event is the one that best describes the accident. Under each, the cases with the same event anywhere in their sequence.

Analysis

According to the pilot, the preflight, engine run-up, taxi, and takeoff from runway 9 were all normal. At 500 feet above ground level (agl) the engine lost power and the pilot maneuvered the airplane for a downwind landing on runway 27. The pilot confirmed the positions of the throttle, propeller, fuel pump, and fuel selector controls and the engine regained power temporarily. About 300 feet agl, the engine again lost power and the pilot elected to land in an off-airport field with the gear up due to the extension time required for the airplane’s landing gear system. During a postaccident examination of the airplane by a Federal Aviation Administration (FAA) inspector, operation of the airframe boost pumps revealed that the pumps would not draw fuel. Closer examination of the fuel selector valve and fuel shut-off cock revealed staining consistent with fuel leakage. When positive pressure was applied to the fuel tanks, fuel leaked around the shaft of the fuel shut-off cock located under the cockpit instrument panel area. Pressure was removed from the tanks, the fuel shut-off cock was sealed with a rag, and the boost pumps were then able to draw fuel when power was applied. Removal of the rag created an air leak, and the boost pumps would not draw fuel. The fuel selector valve and the fuel shut-off cock were then removed, disassembled, and examined under the supervision of the FAA inspector. Examination revealed that the interior O-ring seals for the selector shafts were loose on both. Another owner of the same make and model airplane provided a written account of a nearly identical scenario, which was resolved with the replacement of the O-ring seals. The manufacturer's Special Inspection List outlined "overhaul/replacement" of the fuel shut-off cock every 5 years or 1,500 flight hours, whichever occurred first. At the time of the accident, the airplane had accrued 1,592 total aircraft hours. Seven months, and 8 aircraft hours had elapsed since the airplane's most recent annual inspection. According to the FAA inspector, 14 CFR Part 43, Appendix D, listed the minimum inspection requirements for the completion of an annual inspection, that manufacturer's recommended overhaul schedules were recommended and not mandatory, and that the overall responsibility for the airworthiness of the airplane fell to the owner/operator.

Factual narrative

HISTORY OF FLIGHT On September 4, 2009, about 1330 eastern daylight time, a Siai-Marchetti SF-260, N517P, was substantially damaged following a loss of engine power and forced landing after takeoff at Cobb County Airport (RYY), Atlanta, Georgia. The certificated private pilot and passenger sustained minor injuries. Visual meteorological conditions prevailed, and no flight plan was filed for the local personal flight that was originating at the time of the accident. The flight was conducted under the provisions of 14 Code of Federal Regulations Part 91. According to the pilot, the preflight, engine run-up, taxi, and takeoff from runway 9 were all “normal.” At 500 feet above ground level (agl), the engine lost power, and the pilot maneuvered the airplane for a downwind landing on runway 27. The pilot confirmed the positions of the throttle, propeller, fuel pump, and fuel selector controls and the engine temporarily regained power. About 300 feet agl, the engine again lost power, and the pilot elected to land gear up in a field off-airport, due to the extension time required for the airplane’s landing gear system. The pilot described a “benign” off-airport landing in tall weeds and brush, and he and his passenger were greeted by airport emergency personnel almost immediately after egressing the airplane. PERSONNEL INFORMATION The pilot held a private pilot certificate with a rating for airplane single engine land. His most recent FAA third class medical certificate was issued April 18, 2008. The pilot reported 1,300 total hours of flight experience, of which 369 hours were in the accident airplane make and model. AIRCRAFT INFORMATION According to the owner, the airplane was manufactured in 1968 and had accrued 1,592 total aircraft hours. Its most recent annual inspection was completed on January 30, 2009, at 1,584 total aircraft hours. METEOROLOGICAL INFORMATION At 1346, the weather reported at RYY included few clouds at 3,000 feet and winds from 110 degrees at 12 knots, gusting to 16 knots. The visibility was 10 miles. The temperature was 24 degrees Celsius (C) and the dew point was 15 degrees C. WRECKAGE AND IMPACT INFORMATION Examination of the airplane by an FAA inspector revealed the airplane sustained substantial damage to the nose section, firewall, cabin structure, and empennage. The integrity of the fuel system was verified, and no evidence of fuel contamination was noted during sampling. The airframe fuel filters were inspected as well as the airframe fuel pump filters with no clogs or contamination noted. The carburetor was broken off at its mount; however the lines and controls were still intact. Operation of the airframe boost pumps revealed that the pumps would not draw fuel. Closer examination of the fuel selector valve and fuel shut-off cock revealed staining consistent with fuel leakage. When positive pressure was applied to the fuel tanks, fuel leaked around the shaft of the fuel shut-off cock located under the cockpit instrumentpanel area. Pressure was removed from the tanks, the fuel shut-off cock was sealed with a rag, and the boost pumps were then able to draw fuel when power was applied. Removal of the rag created an air leak, and the boost pumps would not draw fuel. On June 17, 2010, the fuel selector valve and the fuel shut-off cock were removed, disassembled, and examined under the supervision of an FAA inspector. Examination revealed that the interior seals for the selector shafts were "sloppy" on both. The manufacturer's Special Inspection List, outlined "overhaul/replacement" of the fuel shut-off cock every 5 years or 1,500 flight hours, whichever occurred first. According to the inspector, the amount of calendar time that had elapsed between the annual inspection and his post-accident examination of the airplane allowed for the "seal to have possibly leaked at some time after the annual inspection." The FAA inspector was asked to clarify whose responsibility it was to comply with the manufacturer's recommended overhaul schedule. He stated that such schedules were recommended, not mandatory, and that the overall responsibility for the airworthiness of the airplane fell to the owner/operator. According to the inspector, "The IA (inspection authority) performing the inspection is responsible for the inspection as required by CFR Part 43. Appendix D lists the minimum inspection requirements for the completion of an annual inspection. The rules require an annual inspection… There is no requirement that I know of to formally advise the aircraft owner of recommended overhauls." ADDITIONAL INFORMATION Examination of a SIAI-Marchetti "unofficial" website revealed a discussion thread between the website's author and an SF-260 owner about his experience troubleshooting a rough-running engine. That owner was contacted, and he provided a written statement that outlined the diagnosis and solution to the problem he experienced with his airplane. According to the owner, he plumbed a can of fuel directly to the mechanical fuel pump and then to the "upstream side" of the gascolator, and the engine ran smoothly each time, which suggested to him that "the problem was somewhere in the plumbing between the tanks and gascolator." He then plumbed the fuel directly from the right tip tank to the fuel line upstream of the gascolator "bypassing the faulty fuel selector," and the engine ran smoothly again. According to the owner, "The culprit was quickly identified as the 'O' ring (seal) around the stem shaft of the fuel tank selector. On examination we determined that the ring had hardened with age, losing all its pliancy and admitting enough air to cause the roughness in the engine. Installing a fresh 'O' ring cleared up the problem."

Aircraft

Registration
N517P
Reported as
Siai-Marchetti F.260
Category
Airplane
Serial number
106
Airframe hours
1,592
Engine
Lycoming O-540-E4A5, 260 horsepower, reciprocating
Damage
Substantial damage
Flight
Personal · Part 91
Operator
Semonian Gary A
Registered owner
Semonian Gary A
Airworthiness certificate
Standard, Normal
Last inspection
Annual · January 30, 2009 · 8 hours before
Departed
RYY · Atlanta, GA
Destination
RYY · Atlanta, GA
Airport
RYY · Cobb County, runway 09, 6,305 × 100 ft, concrete

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
53
Injuries
Minor
Certificate
Private
Airplane ratings
Single-engine land
Medical
Class 3, Without waivers/limitations
Last flight review
June 28, 2008
Seat
Right
Flight hours
1,300 total · 369 in this make and model · 1,240 as pilot in command · 4 in the last 90 days

Weather

Conditions
Visual (VMC) · Day
Wind
110° at 12 knots, gusting 16
Visibility
10 statute miles
Lowest ceiling
None
Temperature
75 °F, dew point 59 °F
Altimeter
30.13 inHg
Observed at
RYY, 1 nm away

Docket · 6

The files NTSB released with the investigation on October 5, 2010, on NTSB’s docket system: statements, records, photos and specialists’ reports. 2.7 MB in all.

FAA reports on this event · 1

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