# NTSB ANC91FA142: Cessna 208, N9438F, Dillingham, AK, September 3, 1991 - Type: NTSB accident investigation - Classification: Accident · No injuries · Field investigation · Final report - Date: September 3, 1991, 09:53 local (17:53 UTC) - Place: Dillingham, AK - Coordinates: 58.81958, -157.859207 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=58.8196&lon=-157.8592&mi=10 - Phase of flight: [Maneuvering](https://openairdocs.org/ntsb-phases/450) (OpenAirDocs' grouping) - Highest injury: No injuries - Injuries: 1 uninjured - Status: Completed, report April 27, 1993 - Report: Approved by Office Director - NTSB office: Alaska Regional Office - NTSB case key (mKey): 5490 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=ANC91FA142 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/5490/pdf - Page: https://openairdocs.org/ntsb/ANC91FA142 ## Probable cause THE PILOT'S INATTENTIVE PREFLIGHT INSPECTION WHICH RESULTED IN HIS FAILURE TO PROPERLY SECURE THE ENGINE OIL TUBE FILLER CAP RESULTING IN THE LOSS OF ENGINE OIL AND OIL PRESSURE AND THE PILOT'S FAILURE TO PROPERLY COMPENSATE FOR WIND CONDITIONS DURING THE FORCED LANDING. CONTRIBUTING TO THE ACCIDENT WAS THE ENGINE FAILURE AND SUBSEQUENT FORCED LANDING ON SOFT TERRAIN. ## 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, maneuvering - engine assembly - failure,total (contributing factor) - lubricating system,oil filler cap - not secured (cause) - aircraft preflight - inattentive, pilot in command (cause) - Forced landing, descent - emergency - Nose over, landing - roll - terrain condition - soft, pilot in command (contributing factor) - compensation for wind conditions - not performed, pilot in command (cause) ## Analysis THE PILOT IN COMMAND PERFORMED A PREFLIGHT AND CHECKED THE OIL BY REMOVING THE DIP STICK/OIL FILLER CAP. AFTER 10 TO 15 MINUTES OF FLIGHT TIME, THE PILOT NOTICED A DECREASE IN THE TORQUE INDICATION AND ENGINE OIL PRESSURE. HE ELECTED TO RETURN TO DILLINGHAM AND ENROUTE THE ENGINE LOST MORE OIL PRESSURE AND 'COUGHED' TWICE AND THE PILOT FEATHERED THE PROPELLER AND LANDED ON THE TUNDRA. UPON LANDING THE AIRPLANE NOSED OVER. THE ON SITE INSPECTION SHOWED THAT THE LEFT, LOWER SIDE OF THE FUSELAGE WAS COVERED WITH OIL AND THE OIL DIP STICK/FILLER CAP WAS NOT INSTALLED IN THE FILLER NECK. IT WAS RESTING ON THE INSIDE OF THE UPPER COWLING BECAUSE THE AIRPLANE WAS UPSIDE DOWN. THE BRIEF SHOWS THAT THE PILOT WAS THE HOLDER OF AN AIRLINE TRANSPORT PILOT CERTIFICATE BECAUSE THE COMPUTER DATABASE PROGRAM WILL NOT ACCEPT A COMMERCIAL PILOT RATING WHILE SHOWING A SCHEDULED 14 CFR 135, PASSENGER/CARGO TYPE OF OPERATION. THE PILOT IS ONLY THE HOLDER OF A COMMERCIAL PILOT CERTIFICATE. ## Aircraft - Registration: [N9438F](https://openairdocs.org/deregistered/N9438F-2010-09-09), registration cancelled 2010-09-09, S/N 20800053, built 1985 (OpenAirDocs) - Reported make and model: CESSNA 208 - Registry model: [Cessna 208](https://openairdocs.org/model/cessna-208) (registry code 2073702) (OpenAirDocs) - Registry engine: [Pratt & Whitney PT6A series](https://openairdocs.org/engine/pratt-whitney-pt6a-series) (registry code 52034, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: 00053 - Airframe hours: 4080 - Engines: P&W PT6A-114 600 horsepower turbo prop - Damage: Substantial damage - Flight: Part 135 - Operator: Markair Express Inc. - Registered owner: Markair Express Inc. - Airworthiness certificate: Standard, Normal - Last inspection: AAIP, August 4, 1991, 54 hours before - Flight plan: Company VFR ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 29; airline transport; airplane ratings: single-engine land, multi-engine land; instrument ratings: airplane; medical: class 2, valid medical--no waivers/lim.; seat: left; flight hours: 2,222 total, 400 in this make and model, 1,896 as pilot in command, 341 in the last 90 days, 129 in the last 30 days, 3 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 360° at 10 knots - Visibility: 40 statute miles - Lowest ceiling: 5,000 ft overcast - Temperature: 45 °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 19910903037789A](https://openairdocs.org/incident/19910903037789A), Sep 3, 1991: Cessna 208, Dillingham, AK, Substantial damage. Lost oil pressure. Overshot runway. Overturned intundra. Oil filler cap not secured. Ball type check valve not used ## Other investigations on N9438F (1) 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 ANC88FA022](https://openairdocs.org/ntsb/ANC88FA022), Dec 19, 1987: Cessna 208 (N9438F), Bethel, AK, substantial 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.