ANC15LA056

NTSB accident investigation · Piper PA 18-150 · Dillingham, AK · July 21, 2015

Accident · No injuriesLimited investigationFinal report
Date
July 20, 2015, 21:15 local (Jul 21, 2015, 05:15 UTC)
Place
Dillingham, AK
Injuries
2 uninjured
Damage
Substantial damage
Phase of flight
Initial climb
Aircraft
N8761CPiper PA 18-150
Defining event
Initial climb: Loss of lift
Weather
Visual (VMC) · Dusk
Status
Completed · report May 16, 2016
Report
Approved by Office Director
NTSB office
Alaska Regional Office
Parties
FAA
FAA report
20150720014409A
Case key
91640

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 failure to attain adequate airspeed during initial climb after takeoff, which resulted in an aerodynamic stall. Contributing to the accident was the pilot's improper decision to continue a takeoff even though the airplane was not airborne by the planned takeoff decision point.

Findings · 5

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.

Use of equip/info: aircraft controlPersonnel issues › Task performance · PilotPiper PA-18-135: 17 casesAll aircraft: 9,295 casesProbable cause
Performance/control parameters: airspeedAircraft › Aircraft oper/perf/capability · Not attained/maintainedPiper PA-18-135: 4 casesAll aircraft: 1,681 casesProbable cause
Performance/control parameters: angle of attackAircraft › Aircraft oper/perf/capability · Not attained/maintainedPiper PA-18-135: 1 caseAll aircraft: 990 casesProbable cause
Action: incorrect action selectionPersonnel issues › Action/decision · PilotPiper PA-18-135: 1 caseAll aircraft: 397 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 private pilot was conducting a personal flight in the float-equipped airplane. The pilot reported that, after reaching the planned takeoff decision point, the airplane was not airborne, so he applied full flaps, and the airplane then immediately became airborne. The airplane climbed to about 40 ft above ground level, but it had insufficient airspeed to continue climbing and subsequently stalled. In an attempt to avoid impacting the trees ahead, the pilot initiated a left bank, and the airplane subsequently impacted a flat area of muskeg adjacent to the waterway. A postaccident engine examination revealed no mechanical anomalies or malfunctions that would have precluded normal operation. The pilot should not have continued the takeoff given that the airplane had not become airborne by the planned decision takeoff point.

Factual narrative

On July 20, 2015 about 2115 Alaska daylight time, a float equipped, Piper PA-18-150 airplane, N8761C, sustained substantial damage shortly after takeoff from Shannons Pond (0Z3), Dillingham, Alaska. The pilot and passenger were uninjured. The airplane was registered to, and operated by, the private pilot under the provisions of Title 14 Code of Federal Regulations (CFR) Part 91 as a personal flight. Visual meteorological conditions prevailed at the time of the accident, and a visual flight rules (VFR) flight plan was filed. In a statement provided to the National Transportation Safety Board (NTSB) investigator-in-charge (IIC), the pilot stated that during takeoff, after reaching the planned takeoff decision point, full flaps were applied. The airplane immediately became airborne and climbed about 40 feet above ground level (agl).Once reaching that altitude, the airplane did not have the necessary airspeed to continue climbing. In an effort to avoid impacting the trees ahead, a left bank was initiated and the airplane impacted a flat area of muskeg adjacent to Shannons Pond. A post-accident engine exam revealed no mechanical anomalies or malfunctions that would have precluded normal operation. The spark plugs were removed and the propeller was rotated and compression was observed. The closest weather reporting facility is Dillingham Airport, Dillingham, about 3 miles southeast of the accident site. At 2053, an aviation routine weather report (METAR) from the Dillingham Airport was reporting in part: wind from 110 degrees at 7 knots; sky condition, scattered at 8,000 feet agl, scattered at 15,000 agl, broken at 15,000 feet agl; visibility, 30 statute miles; temperature 68 degrees F; dewpoint 52 degrees F; barometric pressure 29.94 inHg.

Aircraft

Registration
N8761C
Reported as
Piper PA 18-150
Category
Airplane
Serial number
18-2848
Built
1953
Airframe hours
4,406.5
Engine
Lycoming O-320-A2B, 150 horsepower, reciprocating
Damage
Substantial damage
Flight
Personal · Part 91
Operator
Flensburg Susan L
Registered owner
Flensburg Susan L
Airworthiness certificate
Standard, Normal; Special, Restricted (Special)
Last inspection
Annual · January 1, 2015 · 12 hours before
Departed
0Z3 · Dillingham, AK
Destination
Dillingham, AK
Flight plan
VFR
Airport
0Z3 · Shannons Pond, runway NE, 1,400 × 100 ft, 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

As NTSB recorded them. NTSB leaves out names.

Role
Pilot
Age
63
Injuries
None
Certificate
Private
Airplane ratings
Single-engine land, Single-engine sea
Medical
Class 3, With waivers/limitations
Last flight review
June 22, 1999
Seat
Front
Restraint
Lap only
Flight hours
889 total · 672 in this make and model · 888 as pilot in command · 13 in the last 90 days · 13 in the last 30 days

Weather

Conditions
Visual (VMC) · Dusk
Wind
110° at 7 knots
Visibility
30 statute miles
Lowest ceiling
15,000 ft broken
Temperature
68 °F, dew point 52 °F
Altimeter
29.94 inHg
Observed at
PADL, 2 nm away

Docket · 2

The files NTSB released with the investigation on April 6, 2016, on NTSB’s docket system: statements, records, photos and specialists’ reports. 1.0 MB 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.