Skip to content

Atlas / NTSB / WPR21LA324

NTSB CAROL · Event

Event WPR21LA324

2021-08-07 Athol, Idaho, United States Airport · ID22 None 1 aircraft Status: Completed

Registry · N4110L

FAA Aircraft Registry record.

Make / Model

CESSNA 172G

Year of manufacture

1966 · 55 years old at event

Engine

CONT MOTOR 0-300 SER (145 hp)

Seats / Engines

4 seats · 1 engine

Last airworthiness date

19660203

ADS-B equipped

Yes — Mode-S A4DA3A

Registrant of record

NEU AVIATION LLC

Source: FAA Aircraft Registry (releasable master file).

Aircraft involved

Probable cause & findings

The failure of the windshield during spin recovery for reasons that were not determined.

Factual narrative

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. Source: NTSB Aviation Accident Database Retrieved: 2026-02-12

NTSB Findings

Hierarchical cause / factor breakdown from the FAA bulk avdata database. Each finding tagged C (Cause) or F (Factor).

  • Aircraft-Aircraft structures-Windows-windshield system-Flight compartment windows-Failure
  • Not determined-Not determined-(general)-(general)-Unknown/Not determined

Verbatim from NTSB's published report. Source file NTSB_2021_WPR21LA324.txt. Findings + structured fields enriched from FAA avall.mdb. Full investigation docket on data.ntsb.gov ↗.

Related research

What the literature says.

Academic papers and agency reports matching this event's aircraft type. Sourced from NASA NTRS, NTSB Safety Studies, FAA CAMI, AOPA Air Safety Institute, Embry-Riddle Scholarly Commons, arXiv, and the Semantic Scholar academic graph.

Browse the full corpus — academia portal ↗