Date of Occurrence: 6 May 2025
Aircraft Type: Boeing 777-2D7F (Freighter)
Registration: N772CK
Operator: Kalitta Air
Engines: 2 × General Electric GE90-110B1
Flight Number: K49772
Route: Oscoda–Wurtsmith Airport (OSC/KOSC) to Cincinnati/Northern Kentucky International Airport (CVG/KCVG)
Occupants: 5 crew
Incident Location: Airspace over Michigan, climbing through FL400
Diversion Airport: Detroit Metropolitan Wayne County Airport (DTW/KDTW)
Event Classification: Serious Incident
Current Status: Aircraft grounded in Cincinnati following onward ferry
Executive Summary
On 6 May 2025, Kalitta Air cargo flight K49772, operating a Boeing 777-200 freighter (registration N772CK), experienced smoke in the cockpit while climbing through FL400 after departure from Oscoda–Wurtsmith Airport. The crew of five reported the smoke condition to ATC and immediately commenced a descent and diversion to Detroit Metropolitan Wayne County Airport.
The aircraft landed without further incident on runway 21L approximately 30 minutes after the onset of the smoke condition. Emergency services met the aircraft on the ground. No injuries were reported. Following an extended ground inspection in Detroit lasting over 37 hours, the aircraft ferried to Cincinnati where it remained grounded as of the latest update.
No preliminary cause has been issued. The event has been classified as a serious incident and is under review by appropriate regulatory bodies, including FAA inspectors and Kalitta’s internal maintenance and safety departments.
Aircraft and Operator Overview
Aircraft Model: Boeing 777-2D7F (Boeing 777F)
Line Number: [Undisclosed]
Manufacturer Serial Number (MSN): [Undisclosed]
Year of Manufacture: [Estimated ~2009, based on operator fleet data]
Engines: 2 × GE90-110B1 high-bypass turbofans
Certifications: ETOPS-330, RVSM, ADS-B Out, ACARS, CPDLC, CAT III ILS
Operator: Kalitta Air (ICAO: CKS)
Primary Mission: Cargo freight operations worldwide
Kalitta Air is a U.S.-based FAR Part 121 cargo airline headquartered in Ypsilanti, Michigan. The company operates a fleet of long-haul freighters including Boeing 747-400Fs, 767-300Fs, and 777Fs, primarily on global logistics and express parcel contracts.
Sequence of Events
Departure and Climb
Flight K49772 departed Oscoda–Wurtsmith Airport (OSC), a former U.S. Air Force base utilised by Kalitta Air for heavy maintenance and cargo dispatch, on a scheduled positioning or cargo delivery run to Cincinnati/Northern Kentucky International Airport (CVG).
The aircraft was climbing under normal performance conditions through FL400 (40,000 feet). This is at the upper end of the 777F’s operational cruise ceiling, typically used for fuel economy and long-haul cruise efficiency.
Smoke Detection and Immediate Response
While passing FL400, the crew reported a smoke condition in the cockpit. The precise origin of the smoke (e.g. avionics bay, environmental control system, electrical panel, or bleed air ducting) was not confirmed publicly at the time of reporting.
Upon detecting the smoke, the crew:
Donned oxygen masks in accordance with Boeing Smoke/Fire/Fumes QRH procedures Engaged recirculation fans and isolation valves as per checklist Initiated a descent away from cruise altitude Advised ATC of the situation, electing to divert to Detroit (DTW) as the nearest suitable airport with full emergency services
The aircraft began a controlled descent and reconfigured for a precautionary landing.
Emergency Descent and Diversion
Detroit Metropolitan Wayne County Airport (DTW/KDTW) was selected as the diversion destination due to:
Proximity (within ~120 nautical miles) Availability of CAT III ILS facilities Long runways suitable for widebody freighters Full-time emergency response capabilities
The descent was executed under controlled conditions. The aircraft:
Was vectored for a straight-in approach to runway 21L, which is 12,003 ft (3,659 m) in length Did not declare a Mayday or PAN PAN publicly, but notified Detroit Approach of abnormal conditions Landed safely and vacated the runway under its own power
The aircraft was met by airfield rescue and firefighting (ARFF) units, who performed an external inspection and stood by until the all-clear was communicated by the flight crew.
Post-Landing Actions
Following landing at approximately 30 minutes after the onset of the issue:
The crew shut down the aircraft at a remote cargo stand The aircraft underwent initial inspection for electrical and air conditioning system faults Maintenance personnel began diagnostics including avionics bay access, air recirculation fan inspection, ECS pack checks, and visual confirmation of insulation or component overheating
The aircraft remained grounded at DTW for over 37 hours for evaluation and clearing of the smoke source. It subsequently flew to Cincinnati under a non-revenue repositioning status, where it remains out of commercial operation as of the latest available update.
Technical Context: Smoke in 777 Flight Deck
The Boeing 777 flight deck is fitted with multiple systems that can contribute to smoke or odour events, including:
Avionics cooling fans Electrical panels and breakers Air conditioning packs (left/right ECS) Bleed air ducting and valves Recirculation fans and HEPA filters
If the smoke originated from the electrical or ECS systems, fault isolation would require:
Download and review of Central Maintenance Computing Function (CMCF) logs Inspection of fault histories for pack overheat, duct leaks, fan motor failures Possible thermal imaging or borescopic inspection of confined wiring or ventilation channels
Cockpit smoke events are typically treated with high urgency due to the risk of:
Crew incapacitation Electrical short circuits or fire Loss of situational awareness under reduced visibility
Flight crews are trained to don smoke goggles and oxygen masks immediately, isolate ventilation systems, and begin QRH fire/fumes/smoke checklist drills as standard protocol.
Regulatory and Safety Oversight
This incident meets the FAA’s criteria for a serious incident, due to:
The presence of smoke in the cockpit Diversion from planned route Potential implications for safety of flight
The Federal Aviation Administration (FAA) has likely assigned inspectors to liaise with Kalitta’s in-house safety and maintenance department. Further findings may be referred to Boeing and GE for systems review if component-level failure is confirmed.
At this time, no formal NTSB investigation has been initiated, nor has a preliminary report been issued by FAA or manufacturer technical support teams.
Maintenance and Aircraft Status
Aircraft: N772CK
Engine Type: GE90-110B1
Maintenance Base: Kalitta main MRO hub (Oscoda/YIP)
Flight Time at Event: [Undisclosed]
Hours Since Last Heavy Check: [Estimated TBD]
On-Ground Time Since Event:
37 hours in Detroit 24+ hours in Cincinnati (as of last known update)
Ongoing maintenance includes:
Diagnostics of cockpit ECS (Environmental Control Systems) Inspections of electrical systems including power buses and breaker panels Examination of avionics bay airflow and recirculation units Leak checks in the bleed air system, particularly for APU and engine-supplied ducting Ground power testing of smoke alarms, packs, and ECAM alerts
Conclusion
The Kalitta Air Boeing 777 freighter incident on 6 May 2025 is a textbook case of effective smoke detection, QRH execution, and safe diversion under non-routine airborne conditions. The crew responded in line with Boeing’s published emergency procedures and demonstrated professional coordination with ATC and emergency services.
The aircraft’s successful landing and absence of injury underscore the effectiveness of training, design redundancies, and crisis handling procedures aboard large freighter aircraft.
The root cause of the smoke condition remains under investigation. Findings will determine if any system-wide technical bulletins or corrective actions are issued by Boeing or GE, particularly concerning the 777’s ECS, electrical, or avionics cooling systems.
Further updates will follow upon the release of any FAA service difficulty reports, operator disclosures, or engineering assessments from Kalitta or its maintenance providers.
Disclaimer
This article is based on publicly available information and reports at the time of writing. While every effort has been made to ensure accuracy, we cannot guarantee the completeness of the information provided.
If you are the rightful owner of any referenced content or images and wish them to be removed, please contact takedown@cockpitking.com.
