Westjet B738 over Pacific on Nov 13th 2014, fumes in cockpit

A Westjet Boeing 737-800, registration C-GAWS performing flight WS-1865 (dep Nov 12th) from Honolulu,HI (USA) to Vancouver,BC (Canada) with 155 people on board, was enroute at FL350 over the Pacific Ocean about 550nm northeast of Honolulu when the crew decided to return to Honolulu due to fumes on the flightdeck, nothing was noticed in the cabin. The aircraft landed safely back in Honolulu about 85 minutes later.

The Canadian TSB reported that numerous ground and taxi tests were conducted by maintenance but nothing was found. About 16 hours after landing the aircraft was ferried to Vancouver as flight WS-8984 where further tests were conducted again without any finding. The aircraft was returned to service.