Hop-A-Jet: ‘We will do all we can to ensure this never happens again’ | Corporate Jet Investor | CJI news

The April 2025 NTSB final report on the February 9, 2024 crash of a Hop-A-Jet Bombardier Challenger 604 (N823KD) has attributed the dual-engine power loss on approach to Naples Municipal Airport (KAPF) to corrosion in the variable geometry systems of the aircraft's General Electric CF34-3B engines. Both engines flamed out during the approach, forcing the crew to execute an emergency landing on Interstate 75, killing Captain Ed Murphy and First Officer Ian Hoffmann. Three cabin occupants survived by exiting through the rear baggage door. The NTSB issued no formal recommendations in the final report, a notable procedural outcome the operator attributes to remedial steps already taken by the engine manufacturer in the form of three service bulletins issued since the accident.

The accident sequence reveals a critical gap between manufacturer troubleshooting logic and operator-level maintenance judgment. A hung start event occurred 25 days before the crash, but the MP68 pressure test — which measures air-fuel mixture pressure in the intake manifold and would have detected the VG system corrosion — was not performed because the engine subsequently started normally and sat far down the manufacturer's troubleshooting flow chart. Hop-A-Jet grounded the aircraft, worked the manufacturer's checklist in sequence over three days and hundreds of gallons of fuel during ground runs, and could never reproduce the fault. The corrosion was never identified. Hop-A-Jet president Barry Ellis has stated publicly that the operator will no longer rely solely on manufacturer troubleshooting guidance following a MEL-triggering event, and has moved the MP68 test to the top of all relevant checklists — a change that is now the subject of a pending FAA airworthiness directive currently in public consultation. That AD, if finalized as described, would mandate boroscope inspections and MP68 testing across the CF34-3B fleet broadly, not only on engines with documented hung starts.

A second and arguably more systemic maintenance failure also lies within the accident chain. The accident aircraft underwent its required 3,200-hour on-condition inspection — heavily boroscope-focused — just six months before the crash, conducted by GE at Hop-A-Jet's facility, with the engines receiving a clean serviceability finding. Ellis has called this inspection a "very big missed opportunity" and is advocating in Hop-A-Jet's forthcoming post-final-report public submission that the 3,200-hour boroscope criteria be substantially strengthened, with corrosion elevated as a primary inspection target rather than a secondary consideration. The gap between a passed boroscope in September 2023 and catastrophic VG corrosion causing a fatal dual engine failure five months later raises foundational questions about whether the current inspection standard for on-condition CF34 engines provides operators with actionable data or merely procedural compliance.

For Part 135 charter operators, corporate flight departments, and maintenance organizations operating CF34-powered aircraft — including the Challenger 600 series — the Hop-A-Jet accident establishes several operational imperatives before the AD is finalized. The case underscores the risk of treating a resolved symptom (an engine that re-starts normally after a hung start) as equivalent to a resolved cause, particularly on aging powerplants where corrosion in control-authority systems may be progressive and non-obvious under standard boroscope criteria. Ellis's public advocacy for more aggressive, baseline-mandatory inspection protocols reflects a broader industry tension between on-condition maintenance philosophy — which trades scheduled hard-time overhauls for condition-monitored flexibility — and the reality that condition monitoring is only as reliable as the inspection criteria used to define airworthiness. The pending AD represents the FAA's opportunity to convert operator-level lessons from this fatal accident into fleet-wide enforceable standards, and its final language will be closely watched by maintenance providers, fleet operators, and insurers across business aviation.