C-GMAN, a Rockwell Intl Aero Commander 690B aircraft operated by MAG Aerospace Canada, was conducting a Bird Dog operation from Red Lake, ON (CYRL) in support of aerial fire suppression 13 nautical miles South of Lac du Bonnet, MB (CYAX). During flight, there was an odour and associated smoke in the cockpit and cabin, that appeared to be unrelated to the smoke generated by the fire on the ground.
The flight crew elected to divert to CYAX and noticed that, when the ground blower automatically shut down at 140 knots, the smoke cleared.
The subsequent landing was uneventful. The operator’s maintenance proceeded to replace the ground blower.