WPR15LA191

NTSB accident investigation · Cessna 180A · Polson, MT · June 19, 2015

Accident · No injuriesLimited investigationFinal report
Date
June 19, 2015, 13:40 local (19:40 UTC)
Place
Polson, MT
Injuries
3 uninjured
Damage
Substantial damage
Phase of flight
Approach
Aircraft
N9699BCessna 180A
Defining event
Approach: Loss of engine power (total)
Weather
Visual (VMC) · Day
Status
Completed · report November 19, 2015
Report
Approved by Office Director
NTSB office
Western Pacific Region
Parties
FAA, FSDO
FAA report
20150619009019A
Case key
91402

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 total loss of engine power during approach for reasons that could not be determined because postaccident examination revealed no anomalies that would have precluded normal operation.

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.

Not determinedNot determined › Not determined · Unknown/Not determinedCessna 180A: 1 caseAll aircraft: 2,247 casesProbable cause
Temp/humidity/pressure: conducive to carburetor icingEnvironmental issues › Conditions/weather/phenomena · Contributed to outcomeCessna 180A: 1 caseAll aircraft: 435 cases

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, while the airplane was on approach and about 3 miles from the airport, the engine lost all power. The pilot continued the descent while maintaining the best glide airspeed and performing the engine restart procedures, which included applying carburetor heat. Despite the pilot's efforts, the engine would not restart, and he initiated a forced landing to a small field. During the landing, the landing gear collapsed, and the right wing impacted terrain. Postaccident examination of the engine and airframe revealed no mechanical anomalies that would have precluded normal operation. About the time of the accident, a weather reporting facility located 37 nautical miles north of the accident site recorded a temperature and dew point that were conducive to the accumulation of carburetor icing at glide power. However, it could not be determined whether carburetor ice caused the power loss.

Factual narrative

On June 19, 2015 about 1340 mountain daylight time, a Cessna 180A, N9699B, was substantially damaged during a forced landing near Polson, Montana. The commercial pilot and two passengers were not injured. The airplane was registered to and operated by the pilot under the provisions of 14 Code of Federal Regulations Part 91. Visual meteorological conditions prevailed for the cross-country flight, and no flight plan was filed. The flight originated from Cavanaugh Bay Airport (66S), Coolin, Idaho at 1140 with a planned destination of Polson Airport (8S1), Polson, Montana.In a written statement, the pilot stated that during approach, about 3 miles from the airport, the engine lost all power. The pilot continued his descent while maintaining the best glide airspeed. He performed the engine restart procedures where he applied carburetor heat. Despite his efforts the engine would not restart and he initiated a forced landing to a small field. During the landing, the right main gear collapsed, subsequently resulting in substantial damage to the right wing and fuselage. The pilot further stated that he had 26 gallons of fuel on board prior to departing 66S. An onsite examination of the wreckage was conducted by a Federal Aviation Administration (FAA) inspector on June 19, 2015. The inspector was present during the transportation process of the wreckage. Seven gallons of fuel was collected from each main tank with some fuel remaining in each. The main fuel line to the carburetor was disconnected and fuel was present. A postaccident examination of the wreckage was conducted on July 6, 2015. The carburetor drain plug was removed and fuel flowed freely from the drain. The gascolator was filled with fuel and free of contaminates. The gascolator was inspected with a flashlight and its screen was free of debris and contaminates. The crankshaft was rotated by hand and engine gear continuity was attained from the propeller assembly to the accessory case. Confirmed compression from all six cylinders and spark from both magnetos were attained. Additionally, on July 20, 2015, the wing tank vent lines and left and right fuel tank caps were examined and revealed no anomalies. The postaccident examination revealed no evidence of mechanical malfunction or failures that would have precluded normal operation. The Glacier Park International Airport, Kalispell (GPI), Montana, located 37 nautical miles north of the accident site, at 1255 the automated weather observation, included winds from 230 degrees at 16 knots, gusting to 23 knots, visibility 10 miles, clear skies, temperature 25 degrees C, dew point 3 degrees C, and an altimeter setting of 29.89 inches of mercury. The GPI 1355 automated weather observation, included winds from 240 degrees at 17 knots, gusting to 22 knots, visibility 10 miles, clear skies, temperature 26 degrees C, dew point 3 degrees C, and an altimeter setting of 29.87 inches of mercury. In the remarks section of the observation, peak winds wererecorded from 220 degrees at 27 knots. Temperature and dew point values for the approximate time of the accident indicated that the relative humidity was approximately 24 percent. When the intersection of the two temperature values was located on a chart that depicted carburetor ice envelopes, the point was in the region of the chart denoted as "Icing at Glide and Cruise Power."

Aircraft

Registration
N9699B
Reported as
Cessna 180A
Category
Airplane
Serial number
32996
Built
1957
Airframe hours
1,973
Engine
Cont Motor O-470 SERIES, 230 horsepower, reciprocating
Damage
Substantial damage
Flight
Personal · Part 91
Operator
Schantz Matthew T
Registered owner
Schantz Matthew T
Airworthiness certificate
Standard, Normal
Last inspection
Annual · October 4, 2014
Departed
66S · Coolin, ID
Destination
8S1 · Polson, MT
Airport
8S1 · Polson, runway 18, 4,195 × 75 ft, asphalt
Equipment
Handheld GPS, ADS-B, Stall warning system

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
34
Injuries
None
Certificates
Commercial, Flight instructor
Airplane ratings
Single-engine land, Multi-engine land
Instrument ratings
Airplane
Medical
Class 2, With waivers/limitations
Seat
Left
Restraint
4-point
Flight hours
2,785 total · 290 in this make and model · 2,703 as pilot in command · 31 in the last 90 days · 13 in the last 30 days · 1 in the last 24 hours

Weather

Conditions
Visual (VMC) · Day
Wind
250° at 14 knots, gusting 22
Visibility
10 statute miles
Temperature
73 °F, dew point 37 °F
Altimeter
30.02 inHg
Observed at
KGPI, 37 nm away

Docket · 6

The files NTSB released with the investigation on October 19, 2015, on NTSB’s docket system: statements, records, photos and specialists’ reports. 3.4 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.

Other investigations on N9699B · 1

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