Flight WS-1770 | Registration: C-FCSX
Date: 31 March 2025 | Location: Enroute, 380 NM SSE of Vancouver, BC, Canada
Flight Details
• Aircraft Type: Boeing 737-800
• Engines: 2 × CFM56-7B26
• Operator: WestJet Airlines
• Registration: C-FCSX
• Flight Number: WS-1770
• Callsign: WJA1770
• Route: Vancouver International Airport (CYVR), Canada to Phoenix Sky Harbor International Airport (KPHX), USA
• Date of Incident: 31 March 2025
• Total Occupants: Estimated 170 (including crew)
• Weather Conditions: No significant weather reported enroute or on arrival
Introduction
On 31 March 2025, a WestJet Boeing 737-800 operating flight WS-1770 from Vancouver to Phoenix was forced to turn back and return to its departure airport after the first officer became medically incapacitated while the aircraft was cruising at FL390. The captain declared a medical emergency and coordinated an immediate return to Vancouver. The aircraft landed safely on runway 08R approximately 65 minutes later. The Canadian Transportation Safety Board (TSB) has confirmed the first officer’s incapacitation and has opened a routine inquiry into the incident.
Sequence of Events
The aircraft departed Vancouver as scheduled and was cruising southbound over the western United States at FL390, approximately 380 nautical miles south-southeast of Vancouver, when the first officer began exhibiting symptoms of medical distress. Details of the condition have not been publicly released, but the situation was deemed serious enough to warrant immediate action.
Upon recognising the incapacitation, the captain assumed full control of the aircraft, declared a medical emergency to ATC, and initiated a return to Vancouver. The flight was prioritised for routing and descent. A diversion to a closer alternate may have been considered, but the crew opted for a return to the well-equipped departure airport, likely due to available medical and operational support.
The captain managed all flight control duties single-handedly for the remainder of the flight. Cabin crew were notified and one member likely assumed the observer seat in the cockpit to provide procedural support, as per airline protocol.
WS-1770 landed safely at Vancouver on runway 08R and was met by airport emergency medical teams. The first officer was transferred to a medical facility for evaluation and treatment. No further disruption or injuries were reported.
Crew & Communication
Upon identification of the first officer’s incapacitation, the captain:
• Assumed pilot flying and monitoring roles
• Informed ATC of the emergency, requesting direct routing back to CYVR
• Declared a medical emergency (PAN or MAYDAY) to ensure priority handling
• Advised the cabin crew and passengers of the return
Standard protocol for incapacitation includes securing the affected crew member in their seat, applying first aid if possible, and having a cabin crew member occupy the cockpit jump seat for communication and checklist support.
ATC facilitated a continuous descent and vectoring back to Vancouver with no reported congestion or delay.
Aircraft Systems & Technical Analysis
This event was not linked to any mechanical or technical malfunction. However, the following systems and protocols were involved:
• Autopilot and Auto-throttle: Assisting the captain with managing workload
• Flight Management System (FMS): Reprogrammed by the captain alone or with support from cabin crew to route back to CYVR
• Cabin Intercom and PA: Used to coordinate medical support onboard and prepare for landing
All aircraft systems performed nominally throughout the flight. There was no requirement for mechanical or operational intervention post-landing, and no mechanical faults were recorded.
Passenger Experience & Cabin Conditions
Passengers were informed mid-flight that the aircraft would be returning to Vancouver due to a medical situation involving a crew member. No in-flight symptoms such as turbulence, depressurisation, or abnormal behaviour were observed.
Cabin crew maintained control of the cabin and reassured passengers, minimising disruption. The return and landing proceeded smoothly.
Passengers were rebooked onto alternate flights to Phoenix later the same day or accommodated overnight depending on availability.
Emergency Response & Aftermath
Emergency medical services met the aircraft upon arrival and provided immediate attention to the first officer. The crew member was transported to a local medical facility for evaluation. WestJet has not publicly disclosed the nature or severity of the illness, citing medical confidentiality.
The aircraft was returned to service following crew rotation and cabin servicing.
The flight rotation for WS-1770 was cancelled, and replacement aircraft and crew were dispatched to cover the schedule.
Investigation Status
The Transportation Safety Board of Canada (TSB) acknowledged the occurrence and classified it as a crew incapacitation event, a reportable incident under aviation safety protocols.
As per standard process, the TSB will review:
• Crew medical certifications and history
• Duty and rest periods prior to the flight
• Flight deck procedures during medical events
• Crew CRM (crew resource management) handling of the emergency
Although rare, pilot incapacitation remains a high-priority area of interest due to the critical nature of flight crew redundancy at high altitude.
No systemic safety threats have been identified, and the event is currently considered isolated.
Root Cause & Contributing Factors
Probable Root Cause:
Incapacitation of the first officer during cruise due to an undisclosed medical condition.
Contributing Factors:
• Potential underlying health condition
• The occurrence at high altitude, where rapid decision-making is essential
• Need for onboard support from cabin crew in single-pilot operation
The captain’s prompt and disciplined execution of procedures ensured the safe return of the aircraft.
Safety Recommendations & Industry Impact
While crew incapacitation is statistically rare, it is an anticipated event within airline training programmes. This incident underscores the importance of:
• Routine medical screening and fitness monitoring for flight crew
• CRM training for handling sudden workload transitions
• Procedures for cabin crew to assist in the cockpit when required
• Access to enroute diversion airports and ground medical coordination
Airlines may use this case in simulator recurrence training to review real-time crew incapacitation scenarios, particularly at cruise levels with full passenger loads.
Conclusion
The successful diversion and safe landing of WestJet flight WS-1770 following the incapacitation of the first officer highlights the professionalism and procedural preparedness of the crew. While the event was serious, it was contained without injury or escalation.
This incident serves as a reminder of the need for continuous vigilance, medical readiness, and crew adaptability during in-flight abnormalities.
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.
