# NTSB ANC98LA138: Grumman G-44, N139F, Dillingham, AK, September 2, 1998 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: September 2, 1998, 10:02 local (18:02 UTC) - Place: Dillingham, AK - Coordinates: 58.819404, -157.860733 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=58.8194&lon=-157.8607&mi=10 - Phase of flight: [Maneuvering](https://openairdocs.org/ntsb-phases/450) (OpenAirDocs' grouping) - Highest injury: No injuries - Injuries: 3 uninjured - Status: Completed, report March 30, 2000 - Report: Approved by Office Director - NTSB office: Alaska Regional Office - NTSB case key (mKey): 43911 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=ANC98LA138 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/43911/pdf - Page: https://openairdocs.org/ntsb/ANC98LA138 ## Probable cause The pilot's failure to maintain clearance with terrain. Contributing factors were the pilot's delayed remedial action (course reversal), low ceilings, rain, fog, and mountainous terrain. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - In flight collision with terrain/water, maneuvering - turn to reverse direction - weather condition - low ceiling (contributing factor) - remedial action - delayed, pilot in command (contributing factor) - weather condition - fog (contributing factor) - clearance - not maintained, pilot in command (cause) - weather condition - rain (contributing factor) - terrain condition - mountainous/hilly (contributing factor) ## Analysis The commercial pilot departed under special VFR conditions on a CFR part 135 flight for a remote lake. During the flight, low clouds, rain, and fog were present in an area of mountainous terrain along the route of flight. The pilot stated that he intended to utilize a narrow mountain pass to transit the area, and as he entered the mountain pass, discovered that the ceiling and visibility would not allow safe passage. He said that he made an emergency 180 degree turn in an attempt to exit the pass, and subsequently collided with terrain. After initial impact, the airplane slid downhill about 100 feet, and came to rest on a 35 degree slope. The pilot stated that weather conditions at the time of the accident consisted of: Ceiling, 500 foot overcast; visibility, 2 miles with rain and fog; wind 360 degrees, at 8 knots. The pilot noted that there were no preaccident anomalies with the airplane. ## Factual narrative On September 2, 1998, about 1002 Alaska daylight time, an amphibious Grumman G-44 airplane, N139F, sustained substantial damage during a collision with mountainous terrain, about 80 miles north of Dillingham, Alaska. The airplane was being operated as a visual flight rules (VFR) on-demand passenger flight under Title 14, CFR Part 135, when the accident occurred. The airplane was operated by Fresh Water Adventures, Inc., Dillingham. The certificated commercial pilot, and the two passengers aboard were not injured. Instrument meteorological conditions prevailed at the time of departure, and company flight following procedures were in effect. The flight originated at the Dillingham Airport, about 0840, under special VFR weather conditions. During a telephone conversation with the National Transportation Safety Board investigator-in-charge on September 2, the pilot reported that he was transporting two hunters to a remote lake located about 100 miles north of Dillingham. During the flight, low clouds, rain, and fog were present in an area of mountainous terrain along the route of flight. The pilot stated that he intended to utilize a narrow mountain pass to transit the area, and as he entered the mountain pass, discovered that the ceiling and visibility would not allow safe passage. He said that he made an emergency 180 degree turn in an attempt to exit the pass, and subsequently collided with terrain. After initial impact, the airplane slid downhill about 100 feet, and came to rest on a 35 degree slope. The airplane sustained substantial damage to the fuselage, wings, and elevator. The pilot stated that weather conditions at the time of the accident consisted of: Ceiling, 500 foot overcast; visibility, 2 miles with rain and fog; wind 360 degrees, at 8 knots. The closest official weather observation station is Dillingham, located about 80 nautical miles southeast of the accident site. On September 2, 1998, at 0925, an Aviation Routine Weather Report (METAR) was reporting, in part: Wind, 330 degrees at 6 knots; visibility, 3 statute miles with light rain and mist; clouds, 500 feet broken, 800 feet overcast; temperature, 48 degrees F; dew point, 48 degrees F; altimeter, 29.34 inHg. The pilot noted that there were no preaccident anomalies with the airplane. ## Aircraft - Registration: [N139F](https://openairdocs.org/deregistered/N139F-2013-01-30), registration cancelled 2013-01-30, S/N 1375, built 1944 (OpenAirDocs) - Reported make and model: Grumman G-44 - Registry model: [Grumman G-44](https://openairdocs.org/model/grumman-g-44) (registry code 3951502) (OpenAirDocs) - Registry engine: [Continental I0-470 series](https://openairdocs.org/engine/continental-i0-470-series) (registry code 17027, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: 1375 - Engines: Continental IO-470-D 260 horsepower reciprocating - Damage: Substantial damage - Flight: Part 135 - Operator: Fresh Water Adventures, doing business as Fresh Water Adventures, Inc. - Registered owner: Lester R. Bingman - Airworthiness certificate: Standard, Normal - Last inspection: 100 hour, September 1, 1998 - Departed: DLG, AK - Flight plan: Company VFR ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 40; commercial; airplane ratings: single-engine sea, multi-engine sea, single-engine land, multi-engine land; instrument ratings: airplane; medical: class 2, valid medical--no waivers/lim.; seat: left; flight hours: 7,800 total, 750 in this make and model, 7,600 as pilot in command, 350 in the last 90 days, 100 in the last 30 days ## Weather - Conditions: Visual (VMC), Day - Wind: 330° at 6 knots - Visibility: 3 statute miles - Lowest ceiling: 500 ft broken - Temperature: 46 °F, dew point 46 °F - Altimeter: 29.00 inHg - Observed at: PAD, 80 nm away ## 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 19980902022179A](https://openairdocs.org/incident/19980902022179A), Sep 2, 1998: Gulstm G44, Dilligham, AK, Substantial damage. Freshwater adventures air taxi crashed en route and sustained subst. Damage other cirucmstances are unknown. (.19)on September 2, 1998, about 1002 Alaska… ## Other investigations on N139F (3) 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 ANC13FA001](https://openairdocs.org/ntsb/ANC13FA001), Oct 8, 2012: Grumman G-44 (N139F), Aleknagik, AK, substantial damage, 1 fatal. Probable cause: The pilot's decision to make multiple low passes over the glassy surface water, which resulted in an impact with the surface of the lake. - [NTSB ANC11LA084](https://openairdocs.org/ntsb/ANC11LA084), Aug 21, 2011: Grumman G-44 (N139F), Dillingham, AK, substantial damage. Probable cause: A loss of directional control during landing due to a rock lodged in the main landing gear wheel brake, resulting in a runway excursion and collision with terrain. - [NTSB ANC95LA071](https://openairdocs.org/ntsb/ANC95LA071), Jun 11, 1995: Grumman G-44 (N139F), Dillingham, AK, substantial damage. Probable cause: THE PILOT'S FAILURE TO REFUEL THE AIRPLANE, AND HIS IMPROPER REMEDIAL ACTION(S) WHICH LEAD TO FUEL STARVATION. 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.