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Atlas / NTSB / CEN18LA164

NTSB CAROL · Event

Event CEN18LA164

2018-04-29 Sioux Falls, South Dakota, United States Airport · FSD None 1 aircraft Status: Completed

Registry · N172GA

FAA Aircraft Registry record.

Make / Model

BEECH 1900C

Seats / Engines

19 seats · 2 engines

ADS-B equipped

Yes — Mode-S A12132

Registrant of record

ALPINE AVIATION INC

Source: FAA Aircraft Registry (releasable master file).

Aircraft involved

Probable cause & findings

Failure of the right main landing gear drag brace bolt for reasons that could not be determined based on the available information.

Factual narrative

On April 29, 2018, about 2230 central daylight time, a Beech 1900C, N172GA, was substantially damaged when the right main landing gear collapsed as the airplane started to taxi for takeoff at Joe Foss Field Airport (FSD), Sioux Falls, South Dakota. The airline transport pilot was not injured. The airplane was registered to and operated by Alpine Aviation, doing business as Alpine Air Express, under the provisions of Title 14 Code of Federal Regulations Part 135 as a non-scheduled domestic cargo flight. Visual meteorological conditions prevailed at the airport at the time of the accident, and an instrument flight rules flight plan had been filed. The flight was originating from FSD, and was destined for Rapid City Regional Airport (RAP), Rapid City, South Dakota. According to Federal Aviation Administration (FAA) inspectors, the airplane had just moved forward to taxi for takeoff when the right main landing gear collapsed. A postaccident examination of the airplane revealed the right main landing gear drag brace bolt failed at the wing forward attach point. The drag brace bolt was not retained for further examination. The strut pivoted aft when the airplane moved forward, and the landing gear collapsed. The aft center wing lower spar cap was dented and deformed up to 0.090". Further examination found pitting corrosion on the spar cap. As the twin-engine, turbopropeller-equipped airplane started to taxi for takeoff, the right main landing gear collapsed, deforming the aft center wing lower spar cap. A postaccident examination of the airplane revealed that the right main landing gear drag brace bolt failed at the wing forward attach point. As the airplane moved forward, the strut pivoted aft, collapsing the landing gear. The drag brace bolt was not retained, and the reason for its failure could not be determined based on the available information. 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-Main landing gear attach sec-Failure - C
  • Aircraft-Aircraft structures-Wing structure-Spar (on wing)-Fatigue/wear/corrosion

Verbatim from NTSB's published report. Source file NTSB_2018_CEN18LA164.txt. Findings + structured fields enriched from FAA avall.mdb. Full investigation docket on data.ntsb.gov ↗.