- Date
- August 7, 2021, 10:30 local (17:30 UTC)
- Place
- Athol, ID · maneuvering at altitude
- Injuries
- 2 uninjured
- Damage
- Substantial damage
- Phase of flight
- Maneuvering
- Aircraft
- N4110LCessna 172
- Defining event
- Maneuvering: Aircraft structural failure
- 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
- FAA-FSDO
- Case key
- 103716
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
The failure of the windshield during spin recovery for reasons that were not determined.
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.
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 flight instructor reported that before demonstrating spin recovery to the student pilot, he confirmed that the weight and balance met the requirements for the utility category. The flight instructor stated that as the spin reached the fully developed state, he began to execute the recovery procedure by reducing power to idle, ailerons remained at neutral, opposite rudder control to stop the turn, and the elevator forward. During the recovery, he noted that the airspeed did not exceed 110 mph which was 12 mph below the design maneuvering speed of 122 mph. Subsequently, the windshield shattered during the recovery process. The flight instructor immediately landed the airplane at the airport that he was maneuvering over without further incident. An examination of the airplane revealed that about half of the windshield separated. The airplane fuselage, wings and empennage were not damaged. The reason for the windshield failure was not determined.
Aircraft
- Registration
- N4110L
- Reported as
- Cessna 172 (G)
- Category
- Airplane
- Serial number
- 17254179
- Built
- 1966
- Airframe hours
- 3,154
- Engine
- Cont Motor 0-300 SER, 145 horsepower, reciprocating
- Damage
- Substantial damage
- Flight
- Instructional · Part 91
- Airworthiness certificate
- None
- Last inspection
- Annual · October 12, 2020 · 74 hours before
- Departed
- COE · Coeur d'Alene, ID
- Destination
- Same as departure
- Airport
- ID22 · Treeport
- Equipment
- Stall warning system, ADS-B
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
- Flight instructor
- Age
- 21
- Injuries
- None
- Certificates
- Commercial, Flight instructor
- Airplane ratings
- Single-engine land, Multi-engine land
- Instrument ratings
- Airplane
- Medical
- Class 1, Without waivers/limitations
- Last flight review
- November 11, 2019
- Seat
- Right
- Restraint
- 3-point
- Flight hours
- 1,480 total · 410 in this make and model · 1,389 as pilot in command · 269 in the last 90 days · 112 in the last 30 days · 5 in the last 24 hours
- Role
- Pilot-rated passenger
- Age
- 20
- Injuries
- None
- Certificate
- Private
- Airplane ratings
- Single-engine land
- Medical
- Class 2, Without waivers/limitations
- Last flight review
- August 6, 2021
- Seat
- Left
- Restraint
- 3-point
- Flight hours
- 63 total · 61 in this make and model · 15 as pilot in command · 63 in the last 90 days · 39 in the last 30 days · 4 in the last 24 hours
Weather
- Conditions
- Visual (VMC) · Day
- Wind
- 180° at 7 knots
- Visibility
- 10 statute miles
- Lowest ceiling
- None
- Temperature
- 70 °F, dew point 54 °F
- Altimeter
- 20.06 inHg
- Icing
- Unknown
- Turbulence
- Unknown
- Observed at
- KCOE, 13 nm away
- METAR
- KCOE 071556Z AUTO 18007KT 10SM CLR 21/12 A2006
Docket · 3
The files NTSB released with the investigation on February 10, 2022, on NTSB’s docket system: statements, records, photos and specialists’ reports. 1.7 MB in all.
Other investigations on N4110L · 1
Matched to the same aircraft by N-number and date.