ANC10LA044

NTSB accident investigation · Dehavilland Beaver DHC-2 MK.1 · Anchorage, AK · May 24, 2010

Accident · No injuriesLimited investigationFinal report
Date
May 23, 2010, 20:00 local (May 24, 2010, 04:00 UTC)
Place
Anchorage, AK
Injuries
3 uninjured
Damage
Substantial damage
Phase of flight
Landing
Aircraft
N4793CDehavilland Beaver DHC-2 MK.1
Defining event
Landing-flare/touchdown: Loss of control on ground
Weather
Visual (VMC) · Day
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)
FAA report
20100523005899A
Case key
76124

From the NTSB’s public API. By law, NTSB reports can’t be used as evidence in lawsuits over the accident.

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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 · 4

NTSB’s coded findings. Those marked are part of the probable cause; the rest are factors or other findings. Under each, the cases with the same finding.

Performance/control parameters: crosswind correctionAircraft › Aircraft oper/perf/capability · Incorrect use/operationDehavilland BEAVER DHC-2 MK.1: 2 casesAll aircraft: 184 casesProbable cause
Wind: crosswindEnvironmental issues › Conditions/weather/phenomena · Contributed to outcomeDehavilland BEAVER DHC-2 MK.1: 1 caseAll aircraft: 1,008 cases
Attention/monitoring: monitoring other personPersonnel issues › Psychological · Instructor/check pilotDehavilland BEAVER DHC-2 MK.1: 1 caseAll aircraft: 200 casesProbable cause

Sequence of events

The events NTSB coded, in order, by phase of flight. The defining event is the one that best describes the accident. Under each, the cases with the same event anywhere in their sequence.

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
Reported as
Dehavilland Beaver DHC-2 MK.1
Category
Airplane
Serial number
296
Airframe hours
95,109
Engine
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

Matched to the registry by N-number and the event date; the registry’s history has gaps, so older matches can be wrong. Compare the reported make and model.

Flight crew · 2

As NTSB recorded them. NTSB leaves out names.

Role
Pilot
Age
70
Injuries
None
Certificate
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
Role
Flight instructor
Age
74
Injuries
None
Certificate
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

Docket · 2

The files NTSB released with the investigation on December 9, 2010, on NTSB’s docket system: statements, records, photos and specialists’ reports. 904 KB in all.

FAA reports on this event · 1

The FAA’s own accident and incident reports, matched to the aircraft by N-number and date.

Other investigations on N4793C · 1

Matched to the same aircraft by N-number and date.