ANC96LA157

NTSB accident investigation · Piper PA-12 · Anchorage, AK · September 16, 1996

Accident · No injuriesLimited investigationFinal report
Date
September 16, 1996, 15:45 local (23:45 UTC)
Place
Anchorage, AK
Injuries
2 uninjured
Damage
Substantial damage
Phase of flight
Enroute
Aircraft
N7658HPiper PA-12
Weather
Visual (VMC) · Day
Status
Completed · report December 15, 1997
Report
Approved by Office Director
NTSB office
Alaska Regional Office
FAA report
19960916028509A
Case key
2907

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 pilot's improper planning/decision, which resulted in loss of engine power due to fuel exhaustion. A factor associated with the accident was: the erroneous (false) indication of the fuel sight tubes.

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.

Loss of engine power(total) - nonmechanicalCruise
Planning/decision - improperPilot in commandCause
Engine instruments,fuel quantity gage - false indicationFactor
Fluid,fuel - exhaustionCause
Forced landingEmergency descent/landing
On ground/water encounter with terrain/waterEmergency landing
Terrain condition - ditch

Analysis

The pilot stated that he had approximately 4.5 hours of fuel on board. He indicated that he tried to conserve fuel during his flight by operating the airplane at a reduced power setting, because he knew that the flight time would be close to the airplane's fuel flight time limits. The engine began to sputter as he was crossing Knik Arm. He applied carburetor heat and noted a small improvement in engine RPM. The engine then lost all power. The pilot stated he attempted to land on water, but was unable to reach the water. He landed on mud flats, and the right float struck a gully during the landing. The float strut collapsed, and the airplane dragged the right wing and elevator. During repair of the airplane after the accident, a mechanic found that the fuel sight tubes would show a greater quantity of fuel than was available.

Factual narrative

On September 16, 1996, at 1545 Alaska daylight time, a float equipped Piper PA-12 airplane, N7658H, registered to and operated by the pilot, experienced a loss of engine power during cruise flight and was forced to land on the mud flats of Knik Arm near Anchorage, Alaska. The personal flight, operating under 14 CFR Part 91, departed Lake Louise, Alaska, and the destination was the Lake Hood Seaplane Base in Anchorage. A visual flight rules flight plan was in effect and visual meteorological conditions prevailed. The certificated private pilot and the passenger were not injured. The airplane received substantial damage.

During a telephone conversation with the pilot on September 17, 1996, he stated that he had approximately 4.5 hours of fuel on board. He was trying to conserve fuel during his flight by operating the airplane at a reduced power setting because he knew that the flight time would place him close to the airplane's fuel flight time limits. The engine began to sputter as he was crossing Knik Arm. He applied carburetor heat and saw a small improvement in engine RPM. The engine then lost all power. The pilot stated he was attempting to land on the water but was unable to reach the water. He landed on the mud flats and the right float struck a gully during landing. The float strut collapsed and the airplane dragged the right wing and elevator.

According to the owner, during the repair of the airplane, the mechanic checked the fuel sight tubes against the quantity of fuel in the fuel tank. He found that the fuel sight tubes showed more fuel available than actually in the fuel tanks.

Aircraft

Registration
N7658H
Reported as
Piper PA-12
Category
Airplane
Serial number
12-537
Airframe hours
3,777
Engine
Lycoming O-320-B2A, 160 horsepower, reciprocating
Damage
Substantial damage
Flight
Personal · Part 91
Registered owner
David L Agosti
Airworthiness certificate
Standard, Normal
Last inspection
Annual · August 6, 1996 · 20 hours before
Departed
13S · Lake Louise, AK
Destination
LHD · AK
Flight plan
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
32
Certificate
Private
Airplane ratings
Single-engine sea, Single-engine land
Medical
Class 2, Valid Medical--w/ waivers/lim
Seat
Front
Flight hours
415 total · 17 in this make and model · 365 as pilot in command

Weather

Conditions
Visual (VMC) · Day
Wind
40° at 8 knots
Visibility
35 statute miles
Lowest ceiling
800 ft broken
Temperature
48 °F, dew point 45 °F
Altimeter
29.00 inHg
Observed at
ANC, 3 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 N7658H · 1

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