Aviation Accident Summaries

Aviation Accident Summary DEN08LA015

Santa Fe, NM, USA

Aircraft #1

N5104K

Ryan Navion

Analysis

According to the pilot, the engine start, taxi, and engine run-up prior to takeoff were normal, without issues, or anomalies. The airplane departed from runway 28. After raising the landing gear, the pilot noted that the engine rpms were dropping through 2,100 rpm. The pilot communicated with the air traffic control tower, performed a 90 degree turn to the left to avoid terrain and obstacles, and performed a forced landing to rough, uneven terrain. During the landing the nosegear assembly and the right main landing gear separated. The airplane rotated 90 degrees to the right, slid, and came to rest on the right wing, resulting in substantial damage. An examination of the engine revealed no anomalies. The fuel selector valve was removed for further examination and testing. The valve exhibited fuel staining on the main tank inlet and fuel line fitting. The gascolator exhibited fuel staining on the top left side of the casting and on the bottom at the fuel sump location. During the vacuum test the valve bled down more than 10 inches in one minute. The gascolater was compromised and leaked severely. Leaks in the fuel selector valve and gascolator can allow air into the fuel system and result in the loss of engine power.

Factual Information

On October 20, 2007, approximately 1110 mountain daylight time, a Ryan Navion N5104K, piloted by a commercial pilot, was substantially damaged during a forced landing after departing the Santa Fe Municipal Airport (SAF), Santa Fe, New Mexico. Visual meteorological conditions prevailed at the time of the accident. The personal flight was being conducted under the provisions of Title 14 Code of Federal Regulations Part 91 on a visual flight rules flight plan. The pilot sustained minor injuries. The cross country flight was originating at the time of the accident and was en route to Moriarty, New Mexico. In a telephone conversation with the pilot, he reported that the engine start, taxi, and engine run-up prior to take-off were normal, without issues or anomalies. The airplane departed from runway 28 (6,300 feet by 75 feet, asphalt). After raising the landing gear, the pilot noted that the engine rpms were dropping through 2,100 rpm. The pilot communicated with the air traffic control tower, performed a 90 degree turn to the left to avoid terrain and obstacles, and performed a forced landing to rough, uneven terrain. During the landing, the nose gear assembly and the right main landing gear separated. The airplane rotated 90 degrees to the right, slid, and came to rest on the right wing. The airplane was examined by an airworthiness inspector with the Federal Aviation Administration (FAA) Flight Standards District Office (FSDO) out of Albuquerque, New Mexico. The rear spar on the right wing was bent, the right landing gear spar was twisted, and the keel member below the engine was bent. An examination of the engine revealed no anomalies. The fuel selector valve was removed on February 6, 2008, for further testing. The valve exhibited fuel staining on the main tank inlet and fuel line fitting. The valve was not stamped with any part numbers or insignia. The fitting was stamped with the number 6 on one side and the letters ASP on the reverse side. The gascolater exhibited fuel staining on the top left side of the casting and on the bottom at the fuel sump location. Koehler 2201B, ASSY K22 0B was cast in the top cover of the gascolater. On March 1, 2008, the fuel selector valve and gascolater assembly was tested at the FAA FSDO in Fresno, California. This FSDO has a test bench specifically designed for testing these fuel selector valves. According to the email from the inspector who tested assembly, the valve leaked "more than is allowed in the test." "It bled down more than 10 [inches] in one minute." The inspector reported that the "gascolator was compromised and leak[ed] severely." No further testing was conducted. According to the FAA, leaks in the fuel selector valve and gascolator can allow air into the fuel system and result in the loss of engine power. Sierra Hotel Aero, Inc. (SHA) currently holds the type certificate for the Ryan Navion. In August of 2005, SHA issued Navion Service Bulletin (SB) 101A - Fuel System - Fuel Selector Valve. The purpose of the SB was to address "wear, causing internal leakage, valve step air ingestion, and improper valve selector positioning." The fuel selector valve was to be removed and replaced with the appropriate valve. In May of 2007, SHA issued Navion SB 106A - Fuel System - Inspection of the fuel system continued safe operation. The purpose of the SB was to inspect the fuel system for leaks and inspect and test the fuel selector valves for fuel staining, detent positions, and leaks. The SB vacuum test allowed for one inch of bleed down in one minute. If the valve exceeded this, it was to be replaced, following the guidelines in SB 101A. According to a photocopy of a logbook page, provided by the FAA, the fuel selector valve was replaced during an annual inspection on April 14, 2000, at tach time of 415.4 hours and an airframe total time of 3,129.2 hours. According to the Pilot/Operator Aircraft Accident Report Form (6120.1) submitted by the pilot, the last annual inspection was conducted on January 25, 2006. According to the FAA, there was no record of compliance with either service bulletin. The airframe total time was 3,503 hours. In April of 2008, the FAA issued an Airworthiness Directive (AD) 2008-05-14 Sierra Hotel Aero, Inc. The purpose of the AD is to "detect and correct fuel system leaks or improperly operating fuel selector valves, which could result in the disruption of fuel flow to the engine. This failure could lead to engine power loss." The AD allows the owner/operator to follow the SB's issued by SHA or the field service bulletin number one issued by the American Navion Society.

Probable Cause and Findings

A leak in the fuel selector valve and gascolator that resulted in fuel starvation during takeoff. Contributing to the accident was a lack of suitable terrain for a forced landing.

 

Source: NTSB Aviation Accident Database

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