21 Air, the North Carolina-based company that operated the Amazon-chartered Boeing 767 cargo plane that crashed near Miami International Airport killing five people, has faced repeated allegations from former employees that it violated aviation safety regulations. The firm, controlled through an LLC by Houston Astros owner Jim Crane, is alleged by ex-pilots to have dismissed staff who raised safety concerns, buried complaints and pressured crews into flights that breached required rest rules, raising questions about the airline's practices ahead of the fatal crash.

Pilot Karl Seuring, who has more than 30 years of flying experience, said 21 Air had "a long-established history of safety problems" and filed a retaliatory-dismissal complaint that was initially rejected by the Occupational Safety and Health Administration before being appealed to a Department of Labor tribunal, where it remains pending. He and other former pilots, including Johnny Salmonson and Bruce Joseph, testified to incidents involving a mechanical fault that pushed a plane beyond safe speeds, a pressurisation problem forcing an emergency diversion, and staff being discouraged from logging safety issues; several of the named individuals involved have disputed the allegations. Separately, it emerged that Miami International Airport's runways lack an Engineered Materials Arresting System, the crushable concrete designed to stop overshooting aircraft, and NTSB chief Jennifer Homendy confirmed the crashed jet had been on its third flight of the day.