The National Transportation Safety Board did not travel to the scene of this accident.
Additional Participating Entity:
Federal Aviation Administration / Flight Standards District Office; Spokane
Location: Athol, Idaho
Accident Number: WPR21LA324
Date and Time: August 7, 2021, 10:30 Local
Registration: N4110L
Aircraft: Cessna 172
Injuries: 2 None
Flight Conducted Under: Part 91: General aviation - Instructional
On August 7, 2021, about 1030 Pacific daylight time, a Cessna 172G, airplane, N4110L, was substantially damaged when it was involved in an accident near Athol, Idaho. The flight instructor and the pilot receiving instruction were not injured. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 personal flight.
The flight instructor reported that after providing some ground instruction on spin maneuver recovery training, he explained that he would demonstrate the first spin and recovery during the flight. They flew to a practice area where they started the spin training at 7,000 ft mean sea level. The flight instructor initiated the first spin, and as the spin reached its fully developed stage, he performed the spin recovery procedure. During the recovery procedure the windshield shattered. Prior to the windshield shattering, the flight instructor noted that the airspeed did not exceed 110 mph. The flight instructor recovered from the spin and started a forced landing to the airplane below. The airplane landed and both were able to exit the airplane without injury.
A post-accident examination of the airplane by a Federal Aviation Administration inspector revealed about 50 percent of the windshield had separated. No other anomalies were noted.
Aircraft and Owner/Operator Information
Aircraft Make: Cessna
Registration: N4110L
Model/Series: 172 G
Aircraft Category: Airplane
Amateur Built:
Operator: On file
Operating Certificate(s) Held: None
Operator Designator Code:
Meteorological Information and Flight Plan
Conditions at Accident Site: VMC
Condition of Light: Day
Observation Facility, Elevation: KCOE,2307 ft msl
Observation Time: 08:56 Local
Distance from Accident Site: 13 Nautical Miles
Temperature/Dew Point: 21°C /12°C
Lowest Cloud Condition: Clear
Wind Speed/Gusts, Direction: 7 knots / , 180°
Lowest Ceiling: None
Visibility: 10 miles
Altimeter Setting: 20.06 inches Hg
Type of Flight Plan Filed: None
Departure Point: Coeur d'Alene, ID (COE)
Destination: Athol, ID
Wreckage and Impact Information
Crew Injuries: 2 None
Aircraft Damage: Substantial
Passenger Injuries:
Aircraft Fire: None
Ground Injuries:
Aircraft Explosion: None
Total Injuries: 2 None
Latitude, Longitude: 47.97796,-116.79269 (est)
I bet that the windshield wasn't the only thing that imploded.
ReplyDeleteInteresting..the airspeed during a spin would be low..I wonder if there was fuselage flex around the windshield. Or, maybe, "spin training " was 20 minutes of flight training spent mainly on spins, but also involved some high airspeed..a not so good spin recovery that "got fast". That's why they call it training, though.
ReplyDeleteAlso, maybe just coincidental timing. Thin, old windshield, years of UV, old stop drilled cracks...I can picture the scene. Or bird?
Not much altitude loss, 1966 bird, old enough for a replacement windshield to get UV'd to weakness. Pilots doing spin training may want to check the logs and set a personal time limit on accepting trainers with older windscreen plastics.
ReplyDeleteHere is the track, zoomed to the spin:
https://globe.adsbexchange.com/?icao=a4da3a&lat=47.948&lon=-116.677&zoom=20.4&showTrace=2021-08-07&trackLabels×tamp=1628358364
I trained in a 1985 172P model back in the late 1980s including spin training. We put that nearly new bird for the era through hell and back (Cessna stopped making the 172 after 1986 for 10 years). I would NOT want to do spins in a 55 year old 172 no matter how new the windscreen is.
ReplyDeleteThe problem with spinning C172 and C152 is they are designed to resist spin entries. So in training instead of getting into a low airspeed spin it ends up being a high speed spiral and an overstressed airframe upon pull out.
ReplyDeleteNo it does not end up being high speed on entry or exit when executed properly.
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