# NTSB ANC16LA062: Dehavilland DHC-2, N91AK, Kodiak, AK, September 9, 2016 - Type: NTSB accident investigation - Classification: Accident · Serious injuries · Class 3 · Limited · Final report - Date: September 9, 2016, 11:30 local (19:30 UTC) - Place: Kodiak, AK - Coordinates: 57.660556, -153.318893 - Nearby events: https://openairdocs.org/map.md?lat=57.6606&lon=-153.3189&mi=10 - Phase of flight: [Initial climb](https://openairdocs.org/ntsb-phases/350) (OpenAirDocs' grouping) - Defining event: [Initial climb: Loss of control in flight](https://openairdocs.org/ntsb-events/240) - Highest injury: Serious injuries - Injuries: 3 serious - Status: Completed - Report: Approved by Office Director - Investigation class: Class 3 - NTSB office: Alaska Regional Office - Parties: Federal Aviation Administration - NTSB case key (mKey): 93982 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=ANC16LA062 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/93982/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=93982 - Page: https://openairdocs.org/ntsb/ANC16LA062 ## Probable cause The pilot's failure to maintain adequate airspeed during the initial climb and turn after takeoff, which resulted in an exceedance of the airplane's critical angle of attack and an aerodynamic stall. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Use of equip/info: aircraft control](https://openairdocs.org/ntsb-findings/02063040): Personnel issues › Task performance · Pilot (probable cause); cases with it: [Dehavilland DHC-2 MK. I(L20A), 8 cases](https://openairdocs.org/ntsb-findings/02063040/cases.md?model=2808002), [All aircraft, 9,295 cases](https://openairdocs.org/ntsb-findings/02063040/cases.md) - [Performance/control parameters: airspeed](https://openairdocs.org/ntsb-findings/01062010): Aircraft › Aircraft oper/perf/capability · Not attained/maintained (probable cause); cases with it: [Dehavilland DHC-2 MK. I(L20A), 1 case](https://openairdocs.org/ntsb-findings/01062010/cases.md?model=2808002), [All aircraft, 1,681 cases](https://openairdocs.org/ntsb-findings/01062010/cases.md) - [Performance/control parameters: angle of attack](https://openairdocs.org/ntsb-findings/01062042): Aircraft › Aircraft oper/perf/capability · Not attained/maintained (probable cause); cases with it: [Dehavilland DHC-2 MK. I(L20A), 2 cases](https://openairdocs.org/ntsb-findings/01062042/cases.md?model=2808002), [All aircraft, 990 cases](https://openairdocs.org/ntsb-findings/01062042/cases.md) - [Terrain: mountainous/hilly terrain](https://openairdocs.org/ntsb-findings/03021010): Environmental issues › Physical environment · Contributed to outcome (probable cause); cases with it: [Dehavilland DHC-2 MK. I(L20A), 1 case](https://openairdocs.org/ntsb-findings/03021010/cases.md?model=2808002), [All aircraft, 329 cases](https://openairdocs.org/ntsb-findings/03021010/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Initial climb: Loss of control in flight](https://openairdocs.org/ntsb-events/240) (defining event); cases with it: [Dehavilland DHC-2 MK. I(L20A), 3 cases](https://openairdocs.org/ntsb-events/240/sequence.md?model=2808002), [All aircraft, 5,002 cases](https://openairdocs.org/ntsb-events/240/sequence.md) - [Uncontrolled descent: Collision with terr/obj (non-CFIT) ](https://openairdocs.org/ntsb-events/470); cases with it: [Dehavilland DHC-2 MK. I(L20A), 7 cases](https://openairdocs.org/ntsb-events/470/sequence.md?model=2808002), [All aircraft, 10,189 cases](https://openairdocs.org/ntsb-events/470/sequence.md) ## Analysis The airline transport pilot was conducting a scheduled commuter flight between remote villages in a float-equipped airplane. After making an intermediate stop to drop off a company maintenance technician at a remote lake, the pilot back-taxied the airplane to the east in preparation for a westerly departure. He estimated the wind at 15 knots with increasing gusts to 25 knots from the west. Ground witnesses and passengers on board the airplane reported that the pilot initiated a takeoff to the west, toward an area of rising, tree-covered terrain. After becoming airborne, the airplane entered a left turn to avoid the terrain. The left turn steepened, and the airplane then entered a steep nose-down descent into the terrain. The pilot reported that he did not recall any preaccident mechanical problems with the airplane. Due to his injuries, he was unable to recall the events of the accident. Postaccident examination revealed no mechanical malfunctions or anomalies of the airplane. Given the witness accounts of the accident, it is likely that the pilot exceeded the airplane's critical angle of attack during the initial climb toward and subsequent turn away from rising terrain, which resulted in an aerodynamic stall and loss of control at an altitude too low for recovery. ## Factual narrative On September 9, 2016, about 1130 Alaska daylight time, a float-equipped, de Havilland DHC-2 (Beaver) airplane, N91AK, sustained substantial damage during a collision with water, following a loss of control shortly after takeoff from Uganik Lake, about 35 miles west-southwest of Kodiak, Alaska. The airplane was registered to Redemption, Inc., and operated as Flight 43 by Island Air, as a visual flight rules (VFR) scheduled commuter flight under the provisions of 14 Code of Federal Regulations (CFR) Part 135. Of the three occupants onboard, the airline transport pilot and two passengers all sustained serious injuries. Visual meteorological conditions prevailed, and company flight following procedures were in effect. Flight 43 originated in Kodiak about 1100, with a preplanned, intermediate stop at Uganik Lake, before continuing to the flights scheduled stops in Amook Bay and Zachar Bay, Alaska. According to the operator's director of maintenance the purpose for the intermediate stop at Uganik Lake was to drop off a maintenance technician. He added that another company owned a Cessna 185 that had landed at Uganik Lake earlier in the day and damaged a float, and the maintenance technician was called in to inspect the float prior to the airplane returning to Kodiak. He said that after landing, the accident pilot met the crew of the Cessna 185 on the western shore of Uganik Lake, where he dropped off the maintenance technician, and then he departed for Amook Bay. Witnesses reported seeing the accident airplane back-taxi to the east before it eventually turned around to start the takeoff run to the west, and towards an area of rising, tree-covered terrain. The witnesses consistently reported that after the airplane became airborne, it began a left turn to avoid the rising terrain ahead. As the airplane flew closer to the rising terrain, the left turn steepened, and the airplane began a steep nose down descent. The airplane subsequently struck the shallow waters on the western end of Uganik Lake, and it came to rest partially submerged. The airplane sustained substantial damage to the wings and fuselage. The witnesses to the accident reported gusty wind conditions, from the west, estimated to be between 15 to 25 knots. Due to injuries sustained in the accident, the pilot did not recall the accident sequence; however, he did remember back-taxiing the airplane to the east for a westerly departure. He also recalled variable wind conditions, estimated to be 15 knots, with increasing gusts to 25 knots from the west. The pilot stated that to the best of his knowledge there were no preimpact mechanical anomalies with the airplane. One of the two passengers reported that he was seated in the right front seat, and his wife was seated just behind the pilot on the left side of the airplane. He added that water conditions consisted of 8 to 12 inches of chop on the surface of the water as the pilot started his westerly takeoff run. He said that just after takeoff,the airplane climbed slower than what he was accustomed to from previous flights. He added that as the airplane continued to climb, he could see an area of rising terrain ahead of them. As the airplane approached the area of rising terrain, he said that the pilot turned the airplane very steeply to the left, and then the airplane nosed down abruptly and then began a nosed down, uncontrolled descent into the shallow water below. ADDITIONAL INFORMATION At the time of the accident, the pilot was using a Garmin GPSMAP 496 portable global positioning system (GPS) receiver, capable of storing route-of-flight data. The GPS data logs for September 9, 2016 supported the pilots, passengers, and witness accounts of the accident. A flight track map overlay, and tabular data corresponding to the accident flight are available in the public docket for this accident. ## Aircraft - Registration: [N91AK](https://openairdocs.org/deregistered/N91AK-2019-01-07), registration cancelled 2019-01-07, S/N 737, built 1954 (OpenAirDocs) - Reported make and model: DEHAVILLAND DHC-2 - Registry model: [Dehavilland DHC-2 MK. I(L20A)](https://openairdocs.org/model/dehavilland-dhc-2-mk-i-l20a) (registry code 2808002) (OpenAirDocs) - Registry engine: [Pratt & Whitney R-985-AN-14B](https://openairdocs.org/engine/pratt-whitney-r-985-an-14b) (registry code 51654, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: 737 - Year built: 1954 - Airframe hours: 26114 - Engines: Pratt & Whittney R985 450 horsepower reciprocating - Damage: Substantial damage - Flight: Part 135 - Operator: Island Air - Registered owner: Redemption Inc DBA - Airworthiness certificate: Standard, Normal - Last inspection: Annual, August 24, 2016 - Departed: Kodiak, AK - Destination: AK81, AMOOK BAY, AK - Flight plan: Company VFR - Equipment: Handheld GPS ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 31; injuries: serious; airline transport; airplane ratings: multi-engine land, single-engine sea, single-engine land; instrument ratings: airplane; medical: class 1, without waivers/limitations; last flight review April 4, 2016; seat: left; restraint: 4-point; flight hours: 3,262 total, 364 in this make and model, 243 in the last 90 days, 82 in the last 30 days, 4 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 270° at 15 knots, gusting 25 - Visibility: 10 statute miles - Lowest ceiling: none ## 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 20160909017009A](https://openairdocs.org/incident/20160909017009A), Sep 9, 2016: Dehavilland DHC-2 MK. I(L20A), Kodiak, AK, Destroyed. On September 9th 2016 at approximately 1130 local time a redemption air inc. de havilland beaver; DHC-2-MK1, N91AK crashed on takeoff at the west end of Uganik… ## Docket (7 files) The files NTSB released with the investigation on October 9, 2020, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=93982. 10.4 MB in all. - Global positioning system device - specialist's factual report (item 1, PDF, 7 pages, 4 photos, 2.1 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=5951400&FileExtension=pdf&FileName=anc16la062_v1_gps_factual-Rel.pdf - Global positioning system device - attachment 1 - tabular data (csv) (item 2, CSV, 14 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=5951603&FileExtension=csv&FileName=ANC16LA062_attach1-Rel.csv - Pilot/operator aircraft accident report, NTSB form 6120.1 (item 3, PDF, 9 pages, 5.3 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=9587329&FileExtension=pdf&FileName=6120%20N91AK_Redacted-Rel.pdf - Record of conversation - pilot (item 4, PDF, 1 page, 51 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=9586931&FileExtension=pdf&FileName=ROC%20Pilot-Rel.pdf - Record of conversation - passengers (item 5, PDF, 2 pages, 53 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=9587042&FileExtension=pdf&FileName=ROC%20Passengers-Rel.pdf - Witness statements (item 6, PDF, 3 pages, 576 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=9586412&FileExtension=pdf&FileName=Witness%20Statements_Redacted-Rel.pdf - Accident photos (item 7, PDF, 3 pages, 3 photos, 2.3 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=9587187&FileExtension=pdf&FileName=Accident%20Photos-Rel.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.