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Atlas / NTSB / CEN18LA360

NTSB CAROL · Event

Event CEN18LA360

2018-08-30 Kenosha, Wisconsin, United States Airport · ENW None 1 aircraft Status: Completed

Registry · N64604

FAA Aircraft Registry record.

Make / Model

BOEING A75N1(PT17)

Engine

P&W R-985 SERIES (450 hp)

Seats / Engines

2 seats · 1 engine

Last airworthiness date

19850703

ADS-B equipped

Yes — Mode-S A87DFA

Registrant of record

ZBONSKI ROBERT J

Source: FAA Aircraft Registry (releasable master file).

Aircraft involved

Probable cause & findings

The failed retaining bolt and cracked backing plate, which resulted in a shift of the brake lining to contact the brake drum and a subsequent wheel lock when the brakes were applied.

Factual narrative

On August 30, 2018, about 1900 central daylight time, a Stearman A75N1 (PT17) airplane, sustained substantial damage when nosed over during the landing roll at the Kenosha Regional Airport (ENW), Kenosha, Wisconsin. The airline transport pilot, who was the sole occupant, was not injured, and the airplane sustained substantial damage to the rudder. The airplane was registered to and operated by a private individual as a Title 14 Code of Federal Regulations Part 91 personal flight. Visual meteorological conditions prevailed at the time of the accident, and a flight plan was not filed. The local flight departed ENW about 1830. According to the pilot, he had performed three touch and go maneuvers without the use of any braking. On the fourth and last planned landing roll out about 30 mph, the airplane experienced an excessive tail wheel shimmy due to a left brake assembly issue. About 25 mph, the airplane nosed over and came to rest inverted. Postaccident examination of the airplane by a Federal Aviation Administration inspector revealed the left main wheel/brake assembly was locked, and the wheel/tire could not be rotated. Partial disassembly of the wheel/brake assembly revealed a failed retaining bolt for the brake backing plate, and a crack in the backing plate. The pilot reported the specified brake lining to drum clearance was .008/.010 inches. The most recent annual inspection was completed on September 1, 2017, about 20 hours prior to the accident. The airline transport pilot had performed three touch-and-go maneuvers without braking. On the fourth and last planned landing roll about 30 mph, the airplane experienced an excessive tailwheel shimmy. About 25 mph, the airplane nosed over and came to rest inverted. Postaccident examination of the airplane revealed that the left main wheel/brake assembly was locked; thus, the wheel/tire could not be rotated. Partial disassembly of the wheel/brake assembly revealed a failed retaining bolt for the brake backing plate and a crack in the backing plate. The bolt likely broke off and became lodged in the assembly; thus, it is likely the failed retaining bolt and cracked backing plate resulted in a shift of the brake lining to contact the brake drum and led to a subsequent wheel lock when the brakes were applied. 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).

  • C Aircraft-Aircraft systems-Landing gear system-Landing gear brakes system-Failure - C
  • C Aircraft-Aircraft oper/perf/capability-Performance/control parameters-(general)-Attain/maintain not possible - C

Verbatim from NTSB's published report. Source file NTSB_2018_CEN18LA360.txt. Findings + structured fields enriched from FAA avall.mdb. Full investigation docket on data.ntsb.gov ↗.