Short answer: you cannot confirm a landing gear mechanical failure from hearsay. Confirmation comes from hard data and physical evidence, primarily the flight data recorder and the cockpit voice recorder, combined with wreckage examination and maintenance records.
From a pilot and operator standpoint here’s what investigators will need to show before calling it a landing gear failure rather than a configuration or procedural issue. First, the objective bits in the flight data recorder. Modern FDRs capture gear status bits and associated system parameters such as landing gear selector/lever position, uplocks/downlocks or gear position sensors, hydraulic system pressures and quantities, and related warnings or CAS/EICAS messages. Correlating those parameters with airspeed, attitude and engine indications is the baseline for determining whether the gear failed to extend or was commanded retracted. These are regulatory recording items in ICAO/EASA/FDR standards and the place to start when reconstructing a landing-configuration anomaly.
Second, the cockpit voice recorder and associated voice and radio timeline. The CVR will show crew callouts, checklist actions, abnormals and any verbal confirmation or confusion about gear position. A recorded “gear down, three green” call or a “gear disagree” alert followed by QRH actions is gold for an accurate sequence. CVR and FDR together are how investigators time an event, confirm checklist compliance and verify whether crew actions to extend the gear were made. CVR and FDR recording duration, preservation and alternate power capability are governed by international standards and national regulation, so preserving and validating those devices is an early investigative priority.
Third, physical and systems evidence. If FDR shows gear did not indicate down and locked, recovery teams will inspect the landing gear actuators, uplock/mechanism components, squat/weight-on-wheels switches, selector valve, downlock uplock pins and hydraulic lines for rupture, contamination or mechanical jamming. A hydraulic loss, contaminated actuator, broken link or jammed oleo could produce the same FDR pattern as an electrical failure of the extension system, so careful teardown and forensic inspection are essential. Skybrary and operational guidance emphasize that hydraulic failures can cascade into multiple system losses affecting gear, brakes, flaps and anti-skid performance.
Fourth, corroborating external sources. Air traffic control transcripts, radar tracks, airport CCTV, witness video and ground-based instrument logs provide time stamps that must match the recorder timelines. ATC recordings will confirm crew calls made to ATC and any controller warnings. If maintenance actions or deferred defects existed on the gear system earlier in the day or on prior sectors, those maintenance records and deferred-item logs will be checked to rule out a progressive fault. Operations dispatch logs and MEL entries are often decisive in ruling in or out latent maintenance issues.
Operationally, some failures are straightforward to identify on the FDR: the landing gear lever moves to down but the gear position bits never transition to down and locked while hydraulic pressure shows depletion or a leak signature. Other scenarios are trickier: for example a transient electrical fault that disables gear position sensing but leaves the mechanical linkage intact, or a partial hydraulic failure that leaves one side down and the other stuck. Investigators will not rely on a single parameter. They will look for consistent cross‑channel evidence across FDR channels, CVR transcript, maintenance history and the wreckage.
Finally, what to watch for in public reporting. Early media claims of a ‘landing gear failure confirmed’ are normally premature. Confirmations in official investigation bulletins reference specific FDR parameters, CVR excerpts, and component examinations. Until an accredited accident investigation authority releases such evidence, any public assertion is speculation. As a pilot and safety professional I look for three things in an official release before I’ll accept ‘‘gear failure confirmed”: (1) a clear FDR trace showing gear handle, gear position bits and hydraulic/electrical parameters; (2) CVR confirmation of crew actions and checklist responses; and (3) a physical component finding that explains why the system did not produce the expected down and locked indication.
If you are an operator or regulator reading this, practical steps that reduce ambiguity in future events are straightforward: ensure FDR/CVR inspections and data integrity checks are current; maintain clear MEL and defect logging procedures so any intermittent gear reports are traceable; and verify alternate gear extension function during maintenance checks when allowed by manufacturer guidance. From a pilot perspective, thorough QRH discipline, timely fuel planning for an abnormal approach and explicit, repeated callouts on approach will make the investigators’ job easier and improve the crew’s chance of a survivable outcome should a gear deployment problem occur.