ANC98LA138

NTSB accident investigation · Grumman G-44 · Dillingham, AK · September 2, 1998

Accident · No injuriesLimited investigationFinal report
Date
September 2, 1998, 10:02 local (18:02 UTC)
Place
Dillingham, AK
Injuries
3 uninjured
Damage
Substantial damage
Phase of flight
Maneuvering
Aircraft
N139FGrumman G-44
Weather
Visual (VMC) · Day
Status
Completed · report March 30, 2000
Report
Approved by Office Director
NTSB office
Alaska Regional Office
FAA report
19980902022179A
Case key
43911

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

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.

Sequence of events

NTSB’s coding before 2008: each occurrence and phase of flight, and the causes and factors under it. The codes are defined in NTSB’s coding manual.

In flight collision with terrain/waterManeuvering - turn to reverse direction
Weather condition - low ceilingFactor
Remedial action - delayedPilot in commandFactor
Weather condition - fogFactor
Clearance - not maintainedPilot in commandCause
Weather condition - rainFactor
Terrain condition - mountainous/hillyFactor

Analysis

The commercial pilot departed under special VFR conditions on a CFR part 135 flight for a remote lake. During the flight, low clouds, rain, and fog were present in an area of mountainous terrain along the route of flight. The pilot stated that he intended to utilize a narrow mountain pass to transit the area, and as he entered the mountain pass, discovered that the ceiling and visibility would not allow safe passage. He said that he made an emergency 180 degree turn in an attempt to exit the pass, and subsequently collided with terrain. After initial impact, the airplane slid downhill about 100 feet, and came to rest on a 35 degree slope. The pilot stated that weather conditions at the time of the accident consisted of: Ceiling, 500 foot overcast; visibility, 2 miles with rain and fog; wind 360 degrees, at 8 knots. The pilot noted that there were no preaccident anomalies with the airplane.

Factual narrative

On September 2, 1998, about 1002 Alaska daylight time, an amphibious Grumman G-44 airplane, N139F, sustained substantial damage during a collision with mountainous terrain, about 80 miles north of Dillingham, Alaska. The airplane was being operated as a visual flight rules (VFR) on-demand passenger flight under Title 14, CFR Part 135, when the accident occurred. The airplane was operated by Fresh Water Adventures, Inc., Dillingham. The certificated commercial pilot, and the two passengers aboard were not injured. Instrument meteorological conditions prevailed at the time of departure, and company flight following procedures were in effect. The flight originated at the Dillingham Airport, about 0840, under special VFR weather conditions.

During a telephone conversation with the National Transportation Safety Board investigator-in-charge on September 2, the pilot reported that he was transporting two hunters to a remote lake located about 100 miles north of Dillingham. During the flight, low clouds, rain, and fog were present in an area of mountainous terrain along the route of flight. The pilot stated that he intended to utilize a narrow mountain pass to transit the area, and as he entered the mountain pass, discovered that the ceiling and visibility would not allow safe passage. He said that he made an emergency 180 degree turn in an attempt to exit the pass, and subsequently collided with terrain. After initial impact, the airplane slid downhill about 100 feet, and came to rest on a 35 degree slope.

The airplane sustained substantial damage to the fuselage, wings, and elevator.

The pilot stated that weather conditions at the time of the accident consisted of: Ceiling, 500 foot overcast; visibility, 2 miles with rain and fog; wind 360 degrees, at 8 knots.

The closest official weather observation station is Dillingham, located about 80 nautical miles southeast of the accident site. On September 2, 1998, at 0925, an Aviation Routine Weather Report (METAR) was reporting, in part: Wind, 330 degrees at 6 knots; visibility, 3 statute miles with light rain and mist; clouds, 500 feet broken, 800 feet overcast; temperature, 48 degrees F; dew point, 48 degrees F; altimeter, 29.34 inHg.

The pilot noted that there were no preaccident anomalies with the airplane.

Aircraft

Registration
N139F
Reported as
Grumman G-44
Category
Airplane
Serial number
1375
Engine
Continental IO-470-D, 260 horsepower, reciprocating
Damage
Substantial damage
Flight
Part 135
Operator
Fresh Water Adventures, doing business as Fresh Water Adventures, Inc.
Registered owner
Lester R. Bingman
Airworthiness certificate
Standard, Normal
Last inspection
100 hour · September 1, 1998
Departed
DLG · AK
Flight plan
Company VFR

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
40
Certificate
Commercial
Airplane ratings
Single-engine sea, Multi-engine sea, Single-engine land, Multi-engine land
Instrument ratings
Airplane
Medical
Class 2, Valid Medical--no waivers/lim.
Seat
Left
Flight hours
7,800 total · 750 in this make and model · 7,600 as pilot in command · 350 in the last 90 days · 100 in the last 30 days

Weather

Conditions
Visual (VMC) · Day
Wind
330° at 6 knots
Visibility
3 statute miles
Lowest ceiling
500 ft broken
Temperature
46 °F, dew point 46 °F
Altimeter
29.00 inHg
Observed at
PAD, 80 nm away

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.