# NTSB ANC11LA084: Grumman G-44, N139F, Dillingham, AK, August 21, 2011 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: August 21, 2011, 09:10 local (17:10 UTC) - Place: Dillingham, AK - Coordinates: 59.044723, -158.505554 - Nearby events: https://openairdocs.org/map.md?lat=59.0447&lon=-158.5056&mi=10 - Phase of flight: [Landing](https://openairdocs.org/ntsb-phases/550) (OpenAirDocs' grouping) - Defining event: [Landing-landing roll: Loss of control on ground](https://openairdocs.org/ntsb-events/230) - Highest injury: No injuries - Injuries: 4 uninjured - Status: Completed, report November 3, 2011 - Report: Approved by Office Director - NTSB office: Alaska Regional Office - Parties: FAA FSDO-03 - NTSB case key (mKey): 81559 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=ANC11LA084 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/81559/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=81559 - Page: https://openairdocs.org/ntsb/ANC11LA084 ## 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. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Performance/control parameters: directional control](https://openairdocs.org/ntsb-findings/01062020): Aircraft › Aircraft oper/perf/capability · Attain/maintain not possible (probable cause); cases with it: [Grumman G-44, 1 case](https://openairdocs.org/ntsb-findings/01062020/cases.md?model=3951502), [All aircraft, 3,958 cases](https://openairdocs.org/ntsb-findings/01062020/cases.md) - [Landing gear system: landing gear brakes system](https://openairdocs.org/ntsb-findings/01023240): Aircraft › Aircraft systems · Malfunction (probable cause); cases with it: [Grumman G-44, 1 case](https://openairdocs.org/ntsb-findings/01023240/cases.md?model=3951502), [All aircraft, 92 cases](https://openairdocs.org/ntsb-findings/01023240/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Landing-landing roll: Loss of control on ground](https://openairdocs.org/ntsb-events/230) (defining event); cases with it: [Grumman G-44, 1 case](https://openairdocs.org/ntsb-events/230/sequence.md?model=3951502), [All aircraft, 4,585 cases](https://openairdocs.org/ntsb-events/230/sequence.md) - [Landing-landing roll: Runway excursion](https://openairdocs.org/ntsb-events/300); cases with it: [Grumman G-44, 1 case](https://openairdocs.org/ntsb-events/300/sequence.md?model=3951502), [All aircraft, 3,643 cases](https://openairdocs.org/ntsb-events/300/sequence.md) - [Landing-landing roll: Collision with terr/obj (non-CFIT) ](https://openairdocs.org/ntsb-events/470); cases with it: [Grumman G-44, 3 cases](https://openairdocs.org/ntsb-events/470/sequence.md?model=3951502), [All aircraft, 10,189 cases](https://openairdocs.org/ntsb-events/470/sequence.md) ## Analysis The pilot reported that, just prior to the accident landing, he had parked the amphibious airplane on a beach where, unknown to him, the left main landing gear wheel brake had apparently captured a small rock in the brake system. On landing at the destination airport, the left brake locked and the airplane departed the left side of the runway, colliding with terrain and sustaining substantial damage to the left wing. A Federal Aviation Administration inspector who went to the accident site confirmed that a small rock was found wedged in the left brake assembly. ## Factual narrative On August 21, about 0910 Alaska daylight time, a Grumman G-44 amphibious airplane, N139F, sustained substantial damage during a runway excursion and collision with terrain, while landing at the Dillingham Airport, Dillingham, Alaska. The airplane was operated by Fresh Water Adventures, Dillingham, as a visual flight rules (VFR) passenger flight under the provisions of 14 Code of Federal Regulations, Part 135, when the accident occurred. The commercial pilot, and the three passengers, were not injured. Visual meteorological conditions prevailed, and a VFR flight plan was in effect. The flight departed Nerka Lake, Alaska, bound for Dillingham, about 0850. During a telephone conversation with the National Transportation Safety Board (NTSB) investigator-in-charge (IIC) on August 21, the Dillingham airport manager said when the airplane touched down it immediately veered off the runway to the left, and collided with terrain. He said the pilot told him the left brake locked up, and he lost directional control. The airplane received substantial damage to the left wing and the left aileron. In a written statement dated August 22, the pilot reported that he was unaware that the left wheel brake system had picked up a rock while departing from a beach at Nerka Lake, which resulted in the left brake locking up on landing. In a written statement dated August 28, an FAA air safety inspector, who had examined the airplane at the accident site, confirmed that a small rock was found lodged in the left brake assembly. ## 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 - Airframe hours: 4090 - Engines: CONT MOTOR IO-470 SERIES 260 horsepower reciprocating; CONT MOTOR IO-470 SERIES 260 horsepower reciprocating - Damage: Substantial damage - Flight: Part 135 - Operator: Fresh Water Adventures Inc, doing business as Fresh Water Adventures - Registered owner: Widgeon Enterprises LLC - Airworthiness certificate: Standard, Normal - Last inspection: 100 hour, May 18, 2011 - Departed: Nerka Lake, AK - Destination: PADL, Dillingham, AK - Flight plan: VFR - Airport: PADL, Dillingham, runway 19, 6,400 × 150 ft, asphalt ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 70; injuries: none; airline transport; airplane ratings: single-engine land, multi-engine land, multi-engine sea, single-engine sea; instrument ratings: airplane; medical: class 1, without waivers/limitations; last flight review June 1, 2011; seat: left; flight hours: 30,000 total, 750 in this make and model, 30,000 as pilot in command ## Weather - Conditions: Visual (VMC), Day - Wind: 230° at 5 knots - Visibility: 20 statute miles - Lowest ceiling: 8,000 ft broken - Temperature: 52 °F, dew point 50 °F - Altimeter: 29.26 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). - [Accident 20110821018149A](https://openairdocs.org/incident/20110821018149A), Aug 21, 2011: Grumman G-44, Dillingham, AK, Substantial damage. On 8/21/2011, Grumman G-44, N139F, was enroute to Dillingham Airport (padl) from the gci lodge located on lake nerka approximately 40.6 nautical miles… ## 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 ANC98LA138](https://openairdocs.org/ntsb/ANC98LA138), Sep 2, 1998: Grumman G-44 (N139F), Dillingham, AK, substantial damage. 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. - [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. ## Docket (2 files) The files NTSB released with the investigation on October 3, 2011, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=81559. 416 KB in all. - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 1, .PDF, 365 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40353642&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Redacted.PDF - FAA Inspector Statement (item 2, .PDF, 51 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40353643&FileExtension=.PDF&FileName=FAA%20Inspector%20Statement-Redacted.PDF 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.