Carbon monoxide in cockpit, both crew having trouble Diverts (2009)

Carbon Monoxide Exposure, Pinnacle CRJ-200, 16 December 2009

Northwest Airlink flight 9E-3947, operated by Pinnacle Airlines with a Canadair CRJ-200, was flying from Minneapolis toward Cleveland on 16 December 2009 when both pilots began experiencing abnormal symptoms during the flight. The aircraft carried 47 passengers and three crew members.

The crew responded by using oxygen masks while continuing to control the aircraft. As the symptoms persisted, the pilots decided to divert to Grand Rapids, Michigan. The decision gave the crew a suitable airport while avoiding the need to continue the longer flight to Cleveland with both pilots affected.

During the diversion, the crew coordinated closely with ATC. They requested the longest suitable runway and asked for the localizer frequency. The radio exchanges remained focused on getting the aircraft safely established for the approach while the pilots were coping with numbness, light-headedness and difficulty thinking.

The crew ultimately landed safely at Grand Rapids approximately thirty minutes after the symptoms began. After landing, carbon monoxide was detected in the cockpit air. The pilots recovered after leaving the aircraft, while the available account reports that passengers and cabin crew were not affected.

The event is notable because both pilots experienced symptoms at the same time. The cockpit therefore lost some of the normal redundancy that exists when one crewmember can compensate for another. The crew's use of oxygen, decision to divert and continued coordination with ATC brought the aircraft to a safe airport before the condition could develop into a loss of control.

Nothing in the available incident record used here establishes a more specific mechanical source for the carbon monoxide exposure. The important operational sequence is clear: abnormal symptoms affected both pilots, oxygen was used, the flight diverted to Grand Rapids and the aircraft landed safely before the cockpit contamination was identified.

“Narration: On Dec 16th 2009, the crew of a Pinnacle Airlines Canadair CRJ-200 on behalf of Northwest Airlines, flight 9E-3947/NW-3947 from Minneapolis,MN to Cleveland,OH (USA)”

Accident Facts

Sources

• Video source (ATC/audio reconstruction)
• Contemporary aviation reporting on Pinnacle Airlines flight 9E-3947.
• Historical ATC recording associated with the flight.
• Video/ATC recording