Narrative:

The following occurred on an small transport in commuter airline operations. This was the first flight of the day for the aircraft and flight crew. Upon entering the aircraft for preflight, flight crew found right hand essential bus tie switch and non essential bus tie switch in off position. Switches were returned to their normal on position. During taxi, flight crew noticed faint odor which smelled very much like the odor caused by water separator lock pollutants. This odor is not uncommon if cabin temperature selector is in full hot position on some of the older aircraft. Crew observed that the cabin temperature selector was in fact, in the full hot position. Crew decided odor was due to water separator sock pollutants due to position of temperature selector. Departed airport. Immediately after takeoff, cockpit began to fill with smoke. Crew observed smoke coming from right hand bus panel. Because both right hand essential bus tie and non essential bus tie switches were in the off position on preflight, crew suspected problem in right hand bus panel. Turned both right hand essential and non essential bus tie switches to off position. Captain called for emergency checklist for smoke in cabin. Crew advised ATC of desire to return for landing. Smoke continued to worsen. Emergency checklist was immediately completed. Smoke did not seem to get any worse, however it did not clear from the cockpit or cabin. Crew advised ATC of problem and requested to return to airport immediately and to have crash fire rescue equipment equipment ready. Since priority for landing was granted, crew elected not to declare an emergency. Also, smoke did not smell of an electrical fire or other combustible type of fire. Smoke had no strong odor at all. Smoke did not cause breathing difficulty and did not irritate eyes in any way. Both right essential and non essential bus tie switches were turned back on and a normal landing was made. Since taxi to parking space was granted almost immediately after exiting runway, crew elected not to initiate an immediate evacuate/evacuation. Also, crew did not believe, in their judgement, that any threat of onboard fire existed. Crew suspected smoke coming from bleed air source. Aircraft was parked and evacuated with minutes of exiting runway after landing. It was later discovered that the smoke was coming through the bleed air system and was caused by spilled hydraulic fluid.

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Original NASA ASRS Text

Title: COMMUTER SMT SMOKE IN COCKPIT AFTER TKOF. RETURN LAND.

Narrative: THE FOLLOWING OCCURRED ON AN SMT IN COMMUTER AIRLINE OPERATIONS. THIS WAS THE FIRST FLT OF THE DAY FOR THE ACFT AND FLT CREW. UPON ENTERING THE ACFT FOR PREFLT, FLT CREW FOUND RIGHT HAND ESSENTIAL BUS TIE SWITCH AND NON ESSENTIAL BUS TIE SWITCH IN OFF POS. SWITCHES WERE RETURNED TO THEIR NORMAL ON POS. DURING TAXI, FLT CREW NOTICED FAINT ODOR WHICH SMELLED VERY MUCH LIKE THE ODOR CAUSED BY WATER SEPARATOR LOCK POLLUTANTS. THIS ODOR IS NOT UNCOMMON IF CABIN TEMP SELECTOR IS IN FULL HOT POS ON SOME OF THE OLDER ACFT. CREW OBSERVED THAT THE CABIN TEMP SELECTOR WAS IN FACT, IN THE FULL HOT POS. CREW DECIDED ODOR WAS DUE TO WATER SEPARATOR SOCK POLLUTANTS DUE TO POS OF TEMP SELECTOR. DEPARTED ARPT. IMMEDIATELY AFTER TKOF, COCKPIT BEGAN TO FILL WITH SMOKE. CREW OBSERVED SMOKE COMING FROM RIGHT HAND BUS PANEL. BECAUSE BOTH RIGHT HAND ESSENTIAL BUS TIE AND NON ESSENTIAL BUS TIE SWITCHES WERE IN THE OFF POS ON PREFLT, CREW SUSPECTED PROB IN RIGHT HAND BUS PANEL. TURNED BOTH RIGHT HAND ESSENTIAL AND NON ESSENTIAL BUS TIE SWITCHES TO OFF POS. CAPT CALLED FOR EMER CHKLIST FOR SMOKE IN CABIN. CREW ADVISED ATC OF DESIRE TO RETURN FOR LNDG. SMOKE CONTINUED TO WORSEN. EMER CHKLIST WAS IMMEDIATELY COMPLETED. SMOKE DID NOT SEEM TO GET ANY WORSE, HOWEVER IT DID NOT CLEAR FROM THE COCKPIT OR CABIN. CREW ADVISED ATC OF PROBLEM AND REQUESTED TO RETURN TO ARPT IMMEDIATELY AND TO HAVE CFR EQUIPMENT READY. SINCE PRIORITY FOR LNDG WAS GRANTED, CREW ELECTED NOT TO DECLARE AN EMER. ALSO, SMOKE DID NOT SMELL OF AN ELECTRICAL FIRE OR OTHER COMBUSTIBLE TYPE OF FIRE. SMOKE HAD NO STRONG ODOR AT ALL. SMOKE DID NOT CAUSE BREATHING DIFFICULTY AND DID NOT IRRITATE EYES IN ANY WAY. BOTH RIGHT ESSENTIAL AND NON ESSENTIAL BUS TIE SWITCHES WERE TURNED BACK ON AND A NORMAL LNDG WAS MADE. SINCE TAXI TO PARKING SPACE WAS GRANTED ALMOST IMMEDIATELY AFTER EXITING RWY, CREW ELECTED NOT TO INITIATE AN IMMEDIATE EVAC. ALSO, CREW DID NOT BELIEVE, IN THEIR JUDGEMENT, THAT ANY THREAT OF ONBOARD FIRE EXISTED. CREW SUSPECTED SMOKE COMING FROM BLEED AIR SOURCE. ACFT WAS PARKED AND EVACUATED WITH MINUTES OF EXITING RWY AFTER LNDG. IT WAS LATER DISCOVERED THAT THE SMOKE WAS COMING THROUGH THE BLEED AIR SYS AND WAS CAUSED BY SPILLED HYD FLUID.

Data retrieved from NASA's ASRS site as of August 2007 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.