# NTSB ANC07LA077: Cessna 185, N720, Bethel, AK, August 9, 2007 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: August 8, 2007, 17:27 local (Aug 9, 2007, 01:27 UTC) - Place: Bethel, AK - Coordinates: 60.8172222222222, -161.768333333333 - Nearby events: https://openairdocs.org/map.md?lat=60.8172&lon=-161.7683&mi=10 - Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping) - Highest injury: No injuries - Injuries: 1 uninjured - Status: Completed, report April 30, 2008 - Report: Approved by Office Director - NTSB office: Alaska Regional Office - Parties: U.S. Department of Interior, Aviation Management, Federal Aviation Administration - NTSB case key (mKey): 66411 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=ANC07LA077 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/66411/pdf - Page: https://openairdocs.org/ntsb/ANC07LA077 ## Probable cause The improper [reversed] installation of the fuel selector handle by maintenance personnel. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - Loss of engine power(total) - nonmechanical, cruise - maintenance,installation - improper, company maintenance personnel (cause) - fuel system,selector/valve - reversed (cause) - Forced landing, emergency descent/landing - terrain condition - water - Nose over, emergency descent/landing - terrain condition - tundra ## Analysis The commercial pilot was repositioning a float-equipped airplane to its mooring site after a 100-hour inspection. About 2 minutes after departure, the pilot reported a loss of engine power, and selected a small pond as a forced landing site. After touchdown on the pond, the airplane collided with the shoreline and nosed over. The airplane sustained substantial damage to the left wing, right wing lift strut, empennage, and fuselage. A postaccident inspection of the airplane revealed that the fuel selector handle had been inadvertently reinstalled incorrectly during the recent 100-hour inspection, and when the fuel tank selector handle was placed in the "Both" position, it actually turned the fuel supply off. Investigation revealed slight wear to the keyed cog of the fuel selector valve handle (female receptacle), as well as slight wear to the fuel selector valve connection point (male receptacle). The combined wear patterns of both the fuel selector valve handle and the fuel selector valve connection point allowed the installation of the fuel selector handle 180 degrees from its correct position. When a new fuel selector valve handle was fitted onto the valve connection point, it could only be installed in the correct position, and not 180 degrees from the correct installation. ## Factual narrative On August 8, 2007, about 1727 Alaska daylight time, a float-equipped Cessna 185 airplane, N720, sustained substantial damage when it nosed over during a forced landing following a loss of engine power, about 2 miles north of Bethel, Alaska. The airplane was being operated as a visual flight rules (VFR) Title 14 CFR Part 91 positioning flight by the U.S. Department of Interior, Aviation Management Directorate, Anchorage, Alaska, when the accident occurred. The solo commercial pilot was not injured. Visual meteorological conditions prevailed, and company flight following procedures were in effect. During a telephone conversation with the National Transportation Safety Board (NTSB) investigator-in-charge (IIC), on August 9, the pilot related that the accident flight was the first flight after a 100-hour inspection. He said that the purpose of the flight was to reposition the airplane to its mooring site, about 2 miles from the maintenance facility. He added that the repositioning flight would also serve as a postmaintenance operational check flight following the 100-hour inspection. The pilot reported that after an uneventful takeoff, he climbed the airplane to about 500 feet agl, and began to configure the airplane for cruise flight. He said that soon after leveling at 400 feet agl, he noted a rough running engine, followed by a gradual reduction in engine rpm. He said that engine emergency procedures did not remedy the engine roughness, which was followed by a rapid loss of engine power, and subsequent loss of altitude. The pilot reported that he was unable to maintain level flight, and he selected a small pond as a forced landing site. After touchdown on the pond, the airplane's floats collided with the soft, tundra-covered shoreline, and the airplane nosed over, sustaining substantial damage to the left wing, right wing lift strut, empennage, and fuselage. Two air safety investigators from the Aviation Management Directorate, in Boise, Idaho, traveled to the accident scene on August 11, 2007, and examined the airplane. The investigators reported that an inspection of the airplane revealed that the fuel selector handle had been inadvertently reinstalled incorrectly during the recent 100-hour inspection. The investigators said that when the fuel tank selector was placed in the "Both" position, it actually turned the fuel supply off. The main fuel valve selector handle is located on the floor, between the two front seats. The three-position handle allows the pilot to select fuel to the engine from either the right or left fuel tanks, or both. The airplane's fuel selector valve assembly is located about 6-inches beneath the airplane's floor. A 6-inch long rigid cable assembly connects the fuel selector valve to the fuel selector handle. Both ends of the rigid cable assembly use a keyed cog, which is designed to prevent maintenance personnel from installing the fuel selector handle incorrectly. The fuel selector handle assembly, along with the rigid cable assembly, were removed from the accident airplane and shipped to the NTSB IIC in Anchorage for inspection. On September 20, 2007, in Wichita, Kansas, the NTSB IIC, along with a senior Cessna Aircraft Company engineering specialist, examined the fuel selector handle and cable assembly that was removed from the accident airplane. The inspection revealed wear marks, with minor rounding of the keyed (male) end of the cog on the rigid cable assembly. In addition, wear marks and a slight elongation of the (female) receptacle on the fuel valve handle was also noted. The combined wear on both the keyed cog on the rigid cable assembly, and wear of the keyed cog on the fuel selector valve handle, inadvertently allowed the installation of the fuel selector handle 180 degrees from the correct position. The Cessna engineer provided the NTSB IIC with a new fuel selector valve handle for comparison. When the new fuel selector handle was fitted on rigid cable assembly, it could only be installed in the correct position, and not 180 degrees from the correct installation. ## Aircraft - Registration: N720 (not matched to a registry record) - Reported make and model: Cessna 185 - Category: Airplane - Serial number: 18504334 - Airframe hours: 2754.2 - Engines: Continental IO-520D 300 horsepower reciprocating - Damage: Substantial damage - Flight: Positioning, Part 91 - Registered owner: U.S. Department of the Interior - Airworthiness certificate: Standard, Normal - Last inspection: Annual, August 1, 2007, 0.1 hours before - Departed: BET, Bethel, AK - Destination: Z58, Bethel, AK - Flight plan: Company VFR ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 56; injuries: none; commercial; airplane ratings: single-engine land, single-engine sea; instrument ratings: airplane; medical: class 2, with waivers/limitations; last flight review February 1, 2007; seat: left; flight hours: 7,168 total, 6,747 as pilot in command, 1 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Visibility: 10 statute miles - Lowest ceiling: 2,100 ft overcast - Temperature: 57 °F, dew point 48 °F - Altimeter: 30.19 inHg - Observed at: BET ## FAA reports on this event (1) The FAA's own accident and incident reports, matched to the aircraft by N-number and date (OpenAirDocs). - [Accident 20070808022709A](https://openairdocs.org/incident/20070808022709A), Aug 8, 2007: Cessna A185F, Bethel, AK, Substantial damage. (-23) Aircraft just came out of 100 hr annual inspection. Preinspection ck list shows l/h tank empty r/h tank 1/2. Fuel selector valve handle and position… From the NTSB's public API. Aircraft are matched to registry aircraft by N-number and event date, checked against the reported serial number, make and model; the registry's history has gaps, so older matches can be wrong. Compare the reported make and model. --- OpenAirDocs.org is an independent research project of [Contrail Labs](https://contraillabs.com/). It is not affiliated with the FAA or the NTSB. Source documents are U.S. government works in the public domain.