# NTSB ANC99LA114: Cessna 206A, N4605F, Cordova, AK, August 15, 1999 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: August 15, 1999, 13:00 local (21:00 UTC) - Place: Cordova, AK - Coordinates: 60.789859, -145.609848 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=60.7899&lon=-145.6098&mi=10 - Phase of flight: [Initial climb](https://openairdocs.org/ntsb-phases/350) (OpenAirDocs' grouping) - Highest injury: No injuries - Injuries: 1 uninjured - Status: Completed, report January 18, 2001 - Report: Approved by Office Director - NTSB office: Alaska Regional Office - NTSB case key (mKey): 47160 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=ANC99LA114 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/47160/pdf - Page: https://openairdocs.org/ntsb/ANC99LA114 ## Probable cause A loss of engine power due to corrosion/blockage of the fuel flow divider vent hole. A factor was unsuitable terrain for a forced landing. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - Loss of engine power(total) - mech failure/malf, takeoff - initial climb - fuel system,fuel flow divider/distributor - corroded (cause) - Forced landing, emergency descent/landing - In flight collision with terrain/water, emergency descent/landing - terrain condition - none suitable (contributing factor) - Nose down, emergency descent/landing ## Analysis The commercial certificated pilot departed from his company's fishing lodge to begin a cross-country business flight. About 300 feet above the ground, the engine suddenly quit. The pilot switched fuel tanks, activated the engine boost pump, and began a turn into the wind. The engine did not restart. The pilot selected an open area of marsh for an emergency landing area. When the airplane touched down, the nose wheel separated from the nose wheel strut, and the airplane nosed down in the soft terrain. The airplane received damage to the engine, propeller, and the left wing. A postaccident examination of the engine by a mechanic found corrosion, and blockage of the vent hole of the engine manifold valve housing. The manifold valve is comprised of a fuel inlet, a diaphragm chamber, and outlet ports for fuel lines to each cylinder. The spring loaded diaphragm operates a valve in the central bore of the lower chamber of the valve body. Fuel pressure below the diaphragm opens the valve to allow fuel to flow to each cylinder. A spring above the diaphragm retains the valve in the closed position, absent any fuel pressure. The upper chamber of the valve housing, containing the spring, is vented to the atmosphere. ## Factual narrative On August 15, 1999, about 1300 Alaska daylight time, a tundra tire equipped Cessna 206A airplane, N4605F, sustained substantial damage during a forced landing in a remote area, about 85 miles east of Cordova, Alaska. The airplane was being operated as a visual flight rules (VFR) cross-country business flight under Title 14 CFR Part 91 when the accident occurred. The airplane was operated by Alaska Expedition Company, Cordova. The commercial certificated pilot, the sole occupant, was not injured. Visual meteorological conditions prevailed. The flight originated at the company's fishing lodge, about 2 minutes before the accident. During a telephone conversation with the National Transportation Safety Board (NTSB) investigator-in-charge (IIC), on August 15, 1999, the pilot reported he was returning to Cordova from his fishing lodge. About 300 feet above the ground, the engine suddenly quit. The pilot switched fuel tanks, activated the engine boost pump, and began a turn into the wind. The engine did not restart. The pilot said he selected an open area of marsh for an emergency landing area. When the airplane touched down, the nose wheel separated from the nose wheel strut, and the airplane nosed down in the soft terrain. The airplane received damage to the engine, propeller, and the left wing. Following the accident, the airplane was ferried to Merrill Field, Anchorage, Alaska, by a mechanic/pilot from Ward's Aero, Anchorage. On September 8, 1999, the mechanic notified the NTSB IIC that he found corrosion, and blockage of the vent hole of the engine manifold valve housing. The manifold valve is comprised of a fuel inlet, a diaphragm chamber, and outlet ports for fuel lines to each cylinder. The spring loaded diaphragm operates a valve in the central bore of the lower chamber of the valve body. Fuel pressure below the diaphragm opens the valve to allow fuel to flow to each cylinder. A spring above the diaphragm retains the valve in the closed position, absent any fuel pressure. The upper chamber of the valve housing, containing the spring, is vented to the atmosphere. The mechanic/pilot said that when he landed in Anchorage at the completion of the ferry flight, he pulled the throttle to idle during the flair. At that time, the engine quit running. ## Aircraft - Registration: [N4605F](https://openairdocs.org/aircraft/N4605F), registered now, S/N P206-0205, built 1966 (OpenAirDocs) - Reported make and model: Cessna 206A - Registry model: [Cessna P206A](https://openairdocs.org/model/cessna-p206a) (registry code 2073308) (OpenAirDocs) - Registry engine: [Continental IO-520 series](https://openairdocs.org/engine/continental-io-520-series) (registry code 17032, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: P206-0205 - Airframe hours: 7260 - Engines: Continental IO-520-F 300 horsepower reciprocating - Damage: Substantial damage - Flight: Business, Part 91 - Operator: Alaska Expedition Company - Registered owner: Charles E. Allen - Airworthiness certificate: Standard, Normal - Last inspection: Annual, March 26, 1999, 35 hours before - Destination: PACV, AK ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 50; commercial; airplane ratings: single-engine land; instrument ratings: airplane; medical: class 2, valid medical--w/ waivers/lim; seat: left; flight hours: 1,967 total, 1,725 in this make and model, 1,934 as pilot in command, 43 in the last 90 days, 27 in the last 30 days, 2 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 135° at 20 knots, gusting 35 - Visibility: 3 statute miles - Lowest ceiling: 600 ft overcast - Temperature: 50 °F ## 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 19990815012149A](https://openairdocs.org/incident/19990815012149A), Aug 15, 1999: Cessna P206A, Cordova, AK, Substantial damage. Acft crashed on takeoff. (-23) at 300 ft AGL after takeoff engine quit. Boost pump did not affect the running of the engine. Made turn back to solid ground.… 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.