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Atlas / NTSB / WPR12CA401

NTSB CAROL · Event

Event WPR12CA401

2012-09-04 Lewiston, Idaho, United States Airport · LWS None 1 aircraft Status: Completed

Registry · N4798Z

FAA Aircraft Registry record.

Make / Model

PIPER PA-22-108

Year of manufacture

1961 · 51 years old at event

Engine

LYCOMING 0-235 SERIES (115 hp)

Seats / Engines

2 seats · 1 engine

Last airworthiness date

19610328

ADS-B equipped

Yes — Mode-S A5E611

Registrant of record

ANDERSON DAVID J

Source: FAA Aircraft Registry (releasable master file).

Aircraft involved

Probable cause & findings

The pilot’s inadequate postmaintenance and preflight inspections, which resulted in the separation of the left main wheel after takeoff. Contributing to the accident was the improperly secured left main wheel spindle nut.

Factual narrative

After departure from an uncontrolled airport, the pilot was advised by personnel at the airport that they saw the left main wheel and tire fall off the airplane. The pilot decided to continue to the accident airport. After flying around to decrease the amount of fuel on the airplane, he landed using runway 30. The airplane pulled to the right until it departed the right side of the runway and tipped onto its nose. The airplane sustained substantial damage to the right wing spar. The pilot reported that he examined the main wheel bearings 2 days prior to the accident for the correct spindle nut tension. He believes that the left wheel spindle nut cotter pin was inadvertently omitted or not installed correctly during the wheel reinstallation on the airplane. He said that a more thorough inspection of the wheel bearing service work should have been performed, and that a more thorough pre-flight inspection could have caught the problem. After departure from an uncontrolled airport, ground personnel advised the pilot that they saw the left main wheel and tire fall off the airplane. The pilot decided to continue flight to a nearby controlled airport, where, after flying around to decrease the amount of fuel on the airplane, he landed. The airplane departed the right side of the runway and tipped onto its nose, which substantially damaged the right wing spar. The pilot reported that he observed no anomalies when he examined the main wheel bearings for the correct spindle nut tension 2 days before the accident. However, he believes that the left wheel spindle nut cotter pin was inadvertently omitted or not installed correctly when he reinstalled the wheel on the airplane. He said that a more thorough inspection of the wheel bearing service work should have been performed, and that a more thorough preflight inspection could have caught the problem. 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/wheel fairing-Inadequate inspection - C
  • C Personnel issues-Task performance-Inspection-Preflight inspection-Pilot - C
  • F Aircraft-Fluids/misc hardware-Misc hardware-(general)-Incorrect service/maintenance - F

Verbatim from NTSB's published report. Source file NTSB_2012_WPR12CA401.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 or causal vocabulary (stall, maintenance). 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 ↗