Incident Overview
A pilot performed an emergency landing after noticing smoke in the cockpit. Shortly before landing, the pilot reported the smoke, opened a vent which cleared it, and landed without incident. However, after landing, the vent did not adequately clear the smoke. The pilot taxied to the ramp, where emergency personnel assisted him from the aircraft. The pilot was treated at a local hospital and released.
Investigation Findings
Rescue personnel examined the aircraft for the smoke source. They noted an occasional odor but found no definite origin or evidence of fire. A post-incident review determined that the engine bleed air pressure regulator had failed, allowing unregulated bleed air into the deice system. The temperature of the unregulated P3 air could reach up to 607 degrees Fahrenheit. The bleed air is routed through a supply line of thin-walled aluminum tubing wrapped in anti-chaffing tape, which runs through the left side door post. The smoke originated from the tape, which overheated due to the unregulated bleed air.
Corrective Action
The failed pressure regulator and pneumatic supply line were replaced. After several monitored flights, the problem did not recur, and the aircraft was returned to service.