- Date
- June 30, 2021, 20:45 local (Jul 1, 2021, 02:45 UTC)
- Place
- Twin Falls, ID
- Injuries
- 1 uninjured
- Damage
- Substantial damage
- Phase of flight
- Maneuvering
- Aircraft
- N9609HChristen Industries A-1
- Defining event
- Maneuvering-low-alt flying: Loss of engine power (partial)
- Weather
- Visual (VMC) · Dusk
- Status
- Completed
- Report
- Approved by Office Director
- Investigation class
- Class 4 - Basic report with no Prelim publish
- NTSB office
- Western Pacific Region
- Parties
- FAA FSDO
- FAA report
- 20210630012419A
- Case key
- 103444
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
Partial loss of engine power during a low pass, due to carburetor icing and the pilot’s failure to use carburetor heat during the landing approach.
Findings · 4
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 pilot reported that he was practicing basic flight maneuvers at an altitude of about 3,500 ft agl during a short uneventful local flight. He then reduced engine power to idle and initiated a descent back to the private dirt airstrip with the intention of first performing a low pass to confirm the runway was clear, and then landing. As he flew past the runway, he applied full throttle, but the engine did not respond. He then performed a forced landing into an adjacent wheat field, where the airplane nosed over during the ground roll. The pilot stated that he had not used a checklist during the descent and forgot to apply carburetor heat. The wing lift struts, and the vertical stabilizer were substantially damaged. The pilot reported that there were no mechanical failures or malfunctions with the airplane or engine that would have precluded normal operation. The carburetor icing chart from FAA Special Airworthiness Information Bulletin CE-09-35 “Carburetor Icing Prevention” indicated a potential for serious icing at glide power for the temperature and dew point depicted at the time of the accident.
Aircraft
- Registration
- N9609H
- Reported as
- Christen Industries A-1
- Category
- Airplane
- Serial number
- 1167
- Built
- 1990
- Airframe hours
- 572.2
- Engine
- Lycoming O-360-C1G, 180 horsepower, reciprocating
- Damage
- Substantial damage
- Flight
- Personal · Part 91
- Operator
- Marc A Williams
- Registered owner
- Marc A Williams
- Airworthiness certificate
- Standard, Normal
- Last inspection
- Annual · November 27, 2020 · 27 hours before
- Departed
- PVT · Hollister, ID
- Destination
- Same as departure
- Airport
- PVT, runway 18, 1,500 × 50 ft, grass/turf
- Equipment
- 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
- 49
- Injuries
- None
- Certificate
- Private
- Airplane ratings
- Single-engine land
- Medical
- Class 3, Without waivers/limitations
- Last flight review
- May 29, 2020
- Seat
- Front
- Restraint
- 5-point
- Flight hours
- 750 total · 145 in this make and model · 675 as pilot in command · 70 in the last 90 days · 16 in the last 30 days · 3.5 in the last 24 hours
Weather
- Conditions
- Visual (VMC) · Dusk
- Wind
- 180° at 9 knots
- Visibility
- 10 statute miles
- Lowest ceiling
- None
- Temperature
- 79 °F, dew point 46 °F
- Altimeter
- 29.93 inHg
- Observed at
- KTWF
- METAR
- METAR KTWF 010253Z AUTO 18009KT 10SM CLR 26/08 A2993 RMK AO2 SLP074 T02610083 55001=
FAA reports on this event · 1
The FAA’s own accident and incident reports, matched to the aircraft by N-number and date.