- Date
- August 11, 2024, 10:34 local (16:34 UTC)
- Place
- Manhattan, MT · 1/2 way between BZN and 9S5
- Injuries
- 2 uninjured
- Damage
- Substantial damage
- Phase of flight
- Enroute
- Aircraft
- N8576YPiper PA-18-150
- Defining event
- Enroute: Loss of engine power (total)
- Weather
- Visual (VMC) · Day
- Status
- Completed
- Report
- Approved by Office Director
- Investigation class
- Class 4 - Basic report with no Prelim publish
- NTSB office
- Western Pacific Region
- Parties
- Federal Aviation Adminstration
- FAA report
- 20240811010309A
- Case key
- 194908
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 due to carburetor icing.
Findings · 1
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.
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 instructor pilot was giving dual instruction to a pilot-rated student. He reported that soon after departure, the airplane engine RPM reduced to idle. The pilot verified the throttle was at full power, adequate fuel was in both tanks and subsequently applied carburetor heat, which restored the engine to full power. After 10 seconds the RPM began surging and the pilot then turned the carburetor heat off. He turned the carburetor heat on again and pumped the throttle repeatedly while the power continued to surge until the engine quit and he lost all power. They were unable to restart the engine and landed the airplane in a nearby agricultural field. The airplane came to rest inverted, which resulted in substantial damage to the vertical stabilizer. The engine ran normally on the ground after the airplane was returned to its upright position following the accident. When the temperature and the dewpoint near the time of the accident were plotted on a carburetor icing probability graph, it was revealed that the airplane was likely operating in meteorological conditions conducive to the formation of carburetor icing (for glide power settings). The pilot reported that there were no preaccident mechanical failures or malfunctions with the airplane that would have precluded normal operation.
Aircraft
- Registration
- N8576Y
- Reported as
- Piper PA-18-150
- Category
- Airplane
- Serial number
- 18-8889
- Built
- 1976
- Airframe hours
- 4,477.7
- Engine
- Lycoming O-320 SERIES, 180 horsepower, reciprocating
- Damage
- Substantial damage
- Flight
- Instructional · Part 91
- Registered owner
- Ridgeline Aviation Inc
- Airworthiness certificate
- Standard, Normal
- Last inspection
- Annual · April 5, 2024 · 28.8 hours before
- Airport
- BZN · Bozeman Yellowstone Intl
- Equipment
- Electronic flight bag or handheld device, ADS-B, Angle of attack indicator
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 · 2
As NTSB recorded them. NTSB leaves out names.
- Role
- Pilot
- Age
- 29
- Injuries
- None
- Certificates
- Commercial, Flight instructor
- Airplane ratings
- Single-engine land
- Instrument ratings
- Airplane
- Medical
- Class 1, Without waivers/limitations
- Last flight review
- July 1, 2024
- Seat
- Rear
- Restraint
- 3-point
- Flight hours
- 544 total · 293 in this make and model · 443 as pilot in command · 80 in the last 90 days · 36 in the last 30 days · 1 in the last 24 hours
- Role
- Pilot
- Age
- 21
- Injuries
- None
- Certificate
- Private
- Airplane ratings
- Single-engine land
- Instrument ratings
- Airplane
- Medical
- Class 3, Without waivers/limitations
- Last flight review
- May 3, 2024
- Seat
- Front
- Restraint
- 3-point
- Flight hours
- 220 total · 5 in this make and model · 154 as pilot in command · 7 in the last 90 days · 4 in the last 30 days · 0 in the last 24 hours
Weather
- Conditions
- Visual (VMC) · Day
- Wind
- Calm
- Visibility
- 10 statute miles
- Lowest ceiling
- None
- Temperature
- 64 °F, dew point 52 °F
- Altimeter
- 30.17 inHg
- Observed at
- KBZN, 8 nm away
- METAR
- METAR KBZN 111656Z 00000KT 10SM CLR 18/11 A3017 RMK AO2 SLP193 T01830111=
Docket · 8
The files NTSB released with the investigation on February 27, 2025, on NTSB’s docket system: statements, records, photos and specialists’ reports. 52.4 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 N8576Y · 1
Matched to the same aircraft by N-number and date.