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Atlas / NTSB / CEN11CA640

NTSB CAROL · Event

Event CEN11CA640

2011-08-25 Cahokia, Illinois, United States Airport · CPS None 1 aircraft Status: Completed

Registry · N44HR

FAA Aircraft Registry record.

Make / Model

CESSNA T210M

Year of manufacture

1978 · 33 years old at event

Engine

CONT MOTOR TSIO-520 SER (300 hp)

Seats / Engines

6 seats · 1 engine

Last airworthiness date

19780524

ADS-B equipped

Yes — Mode-S A54903

Registrant of record

CARDINAL AVIATION SERVICES LLC

Source: FAA Aircraft Registry (releasable master file).

Aircraft involved

Probable cause & findings

A failure of a spring in the main landing gear actuation system that prevented the landing gear from extending.

Factual narrative

The pilot executed a wheel-up landing after normal and emergency extension procedures failed to properly lower the airplane's landing gear. The airplane sustained damage to the propeller, lower fuselage skins, and fuselage bulkheads. Postaccident retraction tests revealed that the landing gear extended and retracted abnormally. Examination of the landing gear system revealed a deformed spring on the up lock sequencing actuator. The spring was replaced and subsequent retraction tests were normal. Review of the hydraulic system for the airplane revealed that a failure of the up lock sequencing actuator could result in hydraulic pressure being directed to both sides of the main landing gear actuators causing the landing gear to not fully extend. No other preexisting anomalies were found. The pilot executed a wheel-up landing after normal and emergency extension procedures failed to properly lower the airplane's landing gear. The airplane sustained damage to the propeller, lower fuselage skins, and fuselage bulkheads. Postaccident retraction tests revealed that the landing gear extended and retracted abnormally. Examination of the landing gear system revealed a deformed spring on the uplock sequencing actuator. The spring was replaced and subsequent retraction tests were normal. Review of the hydraulic system for the airplane revealed that a failure of the uplock sequencing actuator could result in hydraulic pressure being directed to both sides of the main landing gear actuators, causing the landing gear to not fully extend. No other preexisting anomalies were found. 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 actuator-Malfunction - C

Verbatim from NTSB's published report. Source file NTSB_2011_CEN11CA640.txt. Findings + structured fields enriched from FAA avall.mdb. Full investigation docket on data.ntsb.gov ↗.