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Atlas / NTSB / CEN24LA227

NTSB CAROL · Event

Event CEN24LA227

2024-06-10 Colorado Springs, Colorado, United States Airport · COS Minor 1 aircraft Status: Completed

Registry · N321N

FAA Aircraft Registry record.

Make / Model

BEECH D55

Year of manufacture

1968 · 56 years old at event

Engine

CONT MOTOR IO 520 SERIES (285 hp)

Seats / Engines

6 seats · 2 engines

Last airworthiness date

19680613

ADS-B equipped

Yes — Mode-S A37333

Registrant of record

OATMAN SCOTT A

Source: FAA Aircraft Registry (releasable master file).

Aircraft involved

Probable cause & findings

The deflated right main landing gear tire due to a sidewall puncture made by an unknown object, which led to the pilot’s loss of directional control and the landing gear collapse during landing roll.

Factual narrative

The flight instructor and the pilot-receiving-instruction were conducting a nighttime currency/proficiency flight when, after an uneventful landing flare and touchdown, the airplane began to vibrate and veer right during the landing roll. The pilot-receiving-instruction, who was the pilot flying during the landing, released toe brake input but the vibration increased as the airplane continued to veer right. Ultimately, the right main landing gear collapsed, and the airplane came to rest upright in the grass adjacent to the runway. The right wing main spar was substantially damaged when the right wing struck the ground after the landing gear collapsed. Examination of the right main landing gear tire and its tube revealed a sidewall puncture. The puncture was made by an unknown small, sharp object, which left a clean cut on the tube sidewall that measured about 0.25-inch long with the tube deflated, and 0.375-inch long when the tube was reinflated. During the landing roll, it is likely that the tube lost enough pressure that it began to move around the wheel rim until the valve stem severed and there was total loss of remaining tire pressure. The increasing vibration felt by the pilots during landing roll is consistent with a progressive loss of tire pressure, and the increased drag from the deflated right tire would explain airplane’s tendency to veer right. The right main landing gear likely collapsed when the over-center down lock assembly disengaged due to an excessive sideload during the right swerve. 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 systems-Landing gear system-Tire casing-Damaged/degraded
  • Aircraft-Aircraft systems-Landing gear system-Tube-Damaged/degraded
  • Aircraft-Aircraft systems-Landing gear system-Gear extension and retract sys-Capability exceeded
  • Environmental issues-Physical environment-Object/animal/substance-Debris/dirt/foreign object-Effect on equipment
  • Environmental issues-Physical environment-Object/animal/substance-Debris/dirt/foreign object-Ability to respond/compensate
  • Personnel issues-Task performance-Use of equip/info-Aircraft control-Pilot

Verbatim from NTSB's published report. Source file NTSB_2024_CEN24LA227.txt. Findings + structured fields enriched from FAA avall.mdb. Full investigation docket on data.ntsb.gov ↗.