# NTSB ANC94IA049: Cessna 207, N29CF, Anchorage, AK, March 28, 1994 - Type: NTSB incident investigation - Classification: Incident · Minor injuries · Incident investigation · Final report - Date: March 28, 1994, 14:20 local (22:20 UTC) - Place: Anchorage, AK - Coordinates: 61.180038, -149.879974 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=61.1800&lon=-149.8800&mi=10 - Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping) - Highest injury: Minor injuries - Injuries: 1 minor, 3 uninjured - Status: Completed, report January 26, 1995 - Report: Approved by Office Director - NTSB office: Alaska Regional Office - NTSB case key (mKey): 2457 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=ANC94IA049 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/2457/pdf - Page: https://openairdocs.org/ntsb/ANC94IA049 ## Probable cause THE PARTIAL FAILURE OF THE NO. 4 PISTON FROM OVER TEMPERATURE (DETONATION). ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - Loss of engine power(partial) - mech failure/malf, cruise - engine assembly,piston - failure,partial (cause) - engine assembly,piston - overtemperature (cause) - Forced landing, descent - emergency ## Analysis WHILE IN CRUISE FLIGHT ENGINE SUDDENLY BEGAN TO RUN ROUGH AND LOOSE POWER. NO UNUSUAL NOISE WAS ASSOCIATED WITH THE ANOMALY. EXAMINATION OF THE ENGINE REVEALED DAMAGE TO THE UPPER SURFACE OF THE NO. 4 PISTON. THE DAMAGE TO THE PISTON WAS CONSISTENT WITH DETONATION AND SUBSEQUENT RING BREAKAGE. ## Factual narrative On March 28, 1994, at 1420 Alaska daylight time, a wheel equipped Cessna 207 airplane, owned and operated by Spernak Airways, Inc., experienced a loss of engine power while in cruise flight. The airline transport certificated pilot-in-command performed an emergency landing on Sleeper Strip, a private strip located about 4 miles east of Anchorage, Alaska, that is not maintained during the winter. The pilot and his three revenue passengers were not injured and the airplane sustained minor damage. The 14 CFR Part 135 on demand flight last departed Merrill Field Airport, Anchorage, Alaska, at 1415 and the intended destination was Beluga, Alaska. Visual meteorological conditions prevailed and a company VFR flight plan was in effect. The pilot-in-command told the NTSB investigator-in-charge during a personal interview that the airplane was in stabilized cruise flight at an altitude of approximately 1000 feet above the ground when the engine began to run rough and loose power to the point where he could no longer maintain altitude. There were no metallic sounds associated with the engine anomaly. Examination of the engine, a Teledyne Continental IO-540-F, by the NTSB investigator-in-charge revealed substantial damage to the upper surface of the No. 4 cylinder. The cylinder and its associated connecting rod were forwarded to the NTSB's metallurgical laboratory in Washington, D.C. for examination and analysis. The metallurgist's factual report and analysis report are contained in the incident report package. ## Aircraft - Registration: [N29CF](https://openairdocs.org/deregistered/N29CF-2018-02-13), registration cancelled 2018-02-13, S/N 20700353, built 1976 (OpenAirDocs) - Reported make and model: CESSNA 207 - Registry model: [Cessna 207](https://openairdocs.org/model/cessna-207) (registry code 2073602) (OpenAirDocs) - Category: Airplane - Airframe hours: 13480 - Engines: CONTINENTAL IO-520 300 horsepower reciprocating - Damage: Minor damage - Flight: Part 135 - Operator: Spernak Airways, Inc. - Registered owner: Spernak Airways Inc. - Airworthiness certificate: Standard, Normal - Last inspection: 100 hour, March 17, 1994, 40 hours before - Destination: BLG, BELUGA, AK - Flight plan: Company VFR - Airport: Sleeper Strip ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 34; airline transport; airplane ratings: multi-engine land, single-engine land; instrument ratings: airplane; medical: class 2, valid medical--no waivers/lim.; seat: left; flight hours: 10,700 total, 7,200 in this make and model, 9,000 as pilot in command, 200 in the last 90 days, 65 in the last 30 days, 5 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 270° at 5 knots - Visibility: 50 statute miles - Temperature: 43 °F, dew point 25 °F - Altimeter: 29.00 inHg ## FAA reports on this event (1) The FAA's own accident and incident reports, matched to the aircraft by N-number and date (OpenAirDocs). - [Incident 19940328023439I](https://openairdocs.org/incident/19940328023439I), Mar 28, 1994: Cessna 207, Anchorage, AK, Minor damage. Rough engine slight power loss. Elected land in 2 feet wet snow. Private strip. Tore off nose gear. No engine informa ## Other investigations on N29CF (2) 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. - [NTSB ANC03LA085](https://openairdocs.org/ntsb/ANC03LA085), Aug 1, 2003: Cessna 207 (N29CF), Anchorage, AK, substantial damage. Probable cause: The pilot's incorrect positioning of the fuel tank selector valve to a nearly empty tank, which resulted in a loss of engine power due to fuel starvation, and subsequent emergency landing at an… - [NTSB ANC79IA071](https://openairdocs.org/ntsb/ANC79IA071), Jul 14, 1979: Cessna 207 (N29CF), Saltery Cove, AK, incident, no damage 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.