ANC11LA084

NTSB accident investigation · Grumman G-44 · Dillingham, AK · August 21, 2011

Accident · No injuriesLimited investigationFinal report
Date
August 21, 2011, 09:10 local (17:10 UTC)
Place
Dillingham, AK
Injuries
4 uninjured
Damage
Substantial damage
Phase of flight
Landing
Aircraft
N139FGrumman G-44
Defining event
Landing-landing roll: Loss of control on ground
Weather
Visual (VMC) · Day
Status
Completed · report November 3, 2011
Report
Approved by Office Director
NTSB office
Alaska Regional Office
Parties
FAA FSDO-03
FAA report
20110821018149A
Case key
81559

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

On this page

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 · 2

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: directional controlAircraft › Aircraft oper/perf/capability · Attain/maintain not possibleGrumman G-44: 1 caseAll aircraft: 3,958 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 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
Reported as
Grumman G-44
Category
Airplane
Serial number
1375
Airframe hours
4,090
Engines
Cont Motor IO-470 SERIES, 260 horsepower, reciprocatingCont 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

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

As NTSB recorded them. NTSB leaves out names.

Role
Pilot
Age
70
Injuries
None
Certificate
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

Docket · 2

The files NTSB released with the investigation on October 3, 2011, on NTSB’s docket system: statements, records, photos and specialists’ reports. 416 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 N139F · 3

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