# NTSB ANC10LA044: Dehavilland Beaver DHC-2 MK.1, N4793C, Anchorage, AK, May 24, 2010 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: May 23, 2010, 20:00 local (May 24, 2010, 04:00 UTC) - Place: Anchorage, AK - Coordinates: 61.300277, -150.60028 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=61.3003&lon=-150.6003&mi=10 - Phase of flight: [Landing](https://openairdocs.org/ntsb-phases/550) (OpenAirDocs' grouping) - Defining event: [Landing-flare/touchdown: Loss of control on ground](https://openairdocs.org/ntsb-events/230) - Highest injury: No injuries - Injuries: 3 uninjured - Status: Completed, report April 12, 2011 - Report: Approved by Office Director - NTSB office: Alaska Regional Office - Parties: National Transportation Safety Board, Federal Aviation Administration (Operations) - NTSB case key (mKey): 76124 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=ANC10LA044 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/76124/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=76124 - Page: https://openairdocs.org/ntsb/ANC10LA044 ## Probable cause The commercial pilot’s loss of airplane control while landing in a crosswind, resulting in a nose-over. Contributing to the accident was the check pilot's inadequate supervision of the commercial pilot while landing. ## 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 BEAVER DHC-2 MK.1, 9 cases](https://openairdocs.org/ntsb-findings/02063040/cases.md?model=2800102), [All aircraft, 9,295 cases](https://openairdocs.org/ntsb-findings/02063040/cases.md) - [Performance/control parameters: crosswind correction](https://openairdocs.org/ntsb-findings/01062030): Aircraft › Aircraft oper/perf/capability · Incorrect use/operation (probable cause); cases with it: [Dehavilland BEAVER DHC-2 MK.1, 2 cases](https://openairdocs.org/ntsb-findings/01062030/cases.md?model=2800102), [All aircraft, 184 cases](https://openairdocs.org/ntsb-findings/01062030/cases.md) - [Wind: crosswind](https://openairdocs.org/ntsb-findings/03034040): Environmental issues › Conditions/weather/phenomena · Contributed to outcome; cases with it: [Dehavilland BEAVER DHC-2 MK.1, 1 case](https://openairdocs.org/ntsb-findings/03034040/cases.md?model=2800102), [All aircraft, 1,008 cases](https://openairdocs.org/ntsb-findings/03034040/cases.md) - [Attention/monitoring: monitoring other person](https://openairdocs.org/ntsb-findings/02021535): Personnel issues › Psychological · Instructor/check pilot (probable cause); cases with it: [Dehavilland BEAVER DHC-2 MK.1, 1 case](https://openairdocs.org/ntsb-findings/02021535/cases.md?model=2800102), [All aircraft, 200 cases](https://openairdocs.org/ntsb-findings/02021535/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Landing-flare/touchdown: Loss of control on ground](https://openairdocs.org/ntsb-events/230) (defining event); cases with it: [Dehavilland BEAVER DHC-2 MK.1, 6 cases](https://openairdocs.org/ntsb-events/230/sequence.md?model=2800102), [All aircraft, 4,585 cases](https://openairdocs.org/ntsb-events/230/sequence.md) - [Landing-landing roll: Nose over/nose down](https://openairdocs.org/ntsb-events/096); cases with it: [Dehavilland BEAVER DHC-2 MK.1, 4 cases](https://openairdocs.org/ntsb-events/096/sequence.md?model=2800102), [All aircraft, 2,287 cases](https://openairdocs.org/ntsb-events/096/sequence.md) ## Analysis The certificated flight instructor/check pilot was providing an annual corporate flight proficiency check ride to the commercial pilot in a float-equipped airplane. The commercial pilot receiving the proficiency review was appropriately rated and current by Federal Aviation Administration standards to operate float-equipped airplanes. After the commercial pilot completed a series of practice touch-and-go takeoffs and landings to the south, the check pilot asked him to land to the west, which would require a correction for a left crosswind. The check pilot reported that, just after touchdown, the airplane veered immediately to the left, the right float submerged, and the airplane abruptly nosed over. The airplane sustained substantial damage to the wings and fuselage during the accident. Examination of the airplane revealed no preaccident mechanical anomalies. ## Factual narrative On May 23, 2010, about 2000 Alaska daylight time, a float-equipped de Havilland DHC-2 (Beaver) airplane, N4793C, sustained substantial damage while landing on Figure Eight Lake, about 18 miles northwest of Anchorage, Alaska. The airplane was being operated as a visual flight rules (VFR) local area proficiency check flight under Title 14, CFR Part 91, when the accident occurred. The airplane was operated by the Civil Air Patrol Inc. (CAP), Anchorage, Alaska. The three people aboard, a commercial pilot in the left seat, the certificated flight instructor/check pilot in the right seat, and a pilot-rated passenger, were not injured. Visual meteorological conditions prevailed, and CAP flight following procedures were in effect. The flight originated at the Lake Hood Seaplane Base, Anchorage, about 1920. During a telephone conversation with the National Transportation Safety Board (NTSB) investigator-in-charge (IIC) on May 24, the chief of flight safety for the CAP reported that the purpose of the flight was to accomplish a "Form 5" proficiency check of the commercial pilot, in a float-equipped de Havilland DHC-2 airplane. He said that the CAP has an annual check ride, in addition to the Federal Aviation Administration's requirements, for CAP pilots who wish to fly CAP aircraft. He noted that the commercial pilot's most recent biennial flight review was on May 31, 2009. During a telephone conversation with the NTSB IIC on May 26, the check pilot reported that after the commercial pilot completed a series of touch-and-go landings to the south, he asked him to land to the west, which would require a correction for a 6 knot left crosswind. The check pilot reported that just after touchdown, the airplane veered immediately to the left, the right float submerged, and the right wing struck the water. The airplane nosed over abruptly, and the cabin rapidly filled with water. He said that all three occupants struggled to free themselves from their seat belts while upside-down and submerged in cold lake water. He said that just before the airplane's cabin sank, all three were able to exit the airplane just as a float-equipped Cessna 185 arrived on-scene, which took the three occupants to shore. The airplane sustained substantial damage to the wings and fuselage during the accident. According to the CAP's chief of flight safety, all three occupants had attended underwater egress training, which benefited them during their escape from the submerged cabin. On June 11, 2010, following recovery of the airplane’s wreckage to Anchorage, a wreckage examination was done under the direction of the NTSB IIC, and an additional senior NTSB air safety investigator. Also present were two members of the CAP’s safety assessment team. During the wreckage examination, a CAP safety assessment team member reported finding a 2-inch elliptical-shaped dent on the toe of the accident airplane's left float, but the source of the dent is unknown and inconclusive. No preaccidentmechanical anomalies were discovered during the wreckage exam. ## Aircraft - Registration: [N4793C](https://openairdocs.org/deregistered/N4793C-2017-03-21), registration cancelled 2017-03-21, S/N 296, built 1951 (OpenAirDocs) - Reported make and model: DEHAVILLAND BEAVER DHC-2 MK.1 - Registry model: [Dehavilland BEAVER DHC-2 MK.1](https://openairdocs.org/model/dehavilland-beaver-dhc-2-mk-1) (registry code 2800102) (OpenAirDocs) - Registry engine: [Pratt & Whitney R-985 series](https://openairdocs.org/engine/pratt-whitney-r-985-series) (registry code 52008, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: 296 - Airframe hours: 95109 - Engines: P&W R-985 SERIES 450 horsepower reciprocating - Damage: Substantial damage - Flight: Instructional, Part 91 - Operator: Civil Air Patrol Inc - Registered owner: Civil Air Patrol Inc - Airworthiness certificate: Standard, Normal - Last inspection: 100 hour, May 14, 2010, 5 hours before - Departed: LHD, Anchoarge, AK - Destination: Anchorage, AK - Flight plan: Company VFR - Airport: runway 27, water ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 70; injuries: none; commercial; airplane ratings: single-engine land, multi-engine land, single-engine sea; instrument ratings: airplane; medical: class 2, without waivers/limitations; seat: left; flight hours: 1,455 total, 400 in this make and model, 1,350 as pilot in command, 40 in the last 90 days, 20 in the last 30 days, 2 in the last 24 hours - Flight instructor; age 74; injuries: none; commercial; airplane ratings: single-engine sea, single-engine land; instrument ratings: airplane; medical: class 2, with waivers/limitations; last flight review April 17, 2010; seat: right; flight hours: 6,800 total, 800 in this make and model, 5,400 as pilot in command, 48 in the last 90 days, 18 in the last 30 days, 6 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 180° at 6 knots - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 48 °F, dew point 36 °F - Altimeter: 29.70 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 20100523005899A](https://openairdocs.org/incident/20100523005899A), May 23, 2010: Dehavilland BEAVER DHC-, Anchorage, AK, Substantial damage. The certificated flight instructor in the right seat was giving sea plane instruction to the ses rated pilot who occupied the left seat. The pilot receiving… ## Other investigations on N4793C (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 ANC01TA048](https://openairdocs.org/ntsb/ANC01TA048), Apr 20, 2001: de Havilland DHC-2 (N4793C), Anchorage, AK, substantial damage. Probable cause: A failure of the pilot to maintain adequate distance/clearance from a cement barricade while taxiing into a parking spot after landing. A factor was the presence of a barricade adjacent to the… ## Docket (2 files) The files NTSB released with the investigation on December 9, 2010, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=76124. 904 KB in all. - Record of Conversation (item 1, .PDF, 32 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40340458&FileExtension=.PDF&FileName=Record%20of%20Conversation-Master.PDF - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 2, .PDF, 873 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40340558&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-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.