Flight crew distraction smoke in cockpit.

Attributes
ACN	313786
Time
Date	199508
Day	Fri
Local Time Of Day	1201 To 1800
Place
Locale Reference	atc facility : cle
State Reference	OH
Altitude	msl bound lower : 19500 msl bound upper : 28000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zob tower : sff
Operator	general aviation : corporate
Make Model Name	Learjet 25
Operating Under FAR Part	Part 91
Flight Phase	descent other other
Route In Use	enroute : on vectors
Flight Plan	IFR
Person 1
Affiliation	Other
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
ASRS Report	313786
Person 2
Affiliation	Other
Function	flight crew : first officer
Qualification	pilot : commercial pilot : instrument
ASRS Report	313787
Events
Anomaly	aircraft equipment problem : critical non adherence other
Independent Detector	other flight crewa other other : unspecified
Resolutory Action	flight crew : exited adverse environment flight crew : overcame equipment problem flight crew : declared emergency
Consequence	Other
Supplementary
Primary Problem	Aircraft
Air Traffic Incident	Pilot Deviation

Narrative:

While descending through FL300 we started to smell burning in the cabin. We immediately turned off all unnecessary electrical equipment and smell continued. Descending through approximately FL240 smoke started filling the cabin. We donned oxygen masks and dropped masks for passenger. I told the controller that we had smoke in the cabin and needed lower. Not knowing what was causing the problem, I asked the controller what was the nearest airport to which he said, 'cleveland.' I said that initially I would like to head for cleveland. Sometime while this was taking place, we were cleared to 12000 ft. At this time my passenger came forward and said he thought the smoke was coming from the cabin blower. I looked at the fan switch which is very small in the lear and it was on. I immediately turned it off. Within a few seconds the smoke stopped. We were at FL195. Feeling comfortable that this was the problem, I asked the controller for FL190 and received it. The cabin returned to normal and we asked for a clearance to descend normally into detroit and land at our maintenance base. No further problems arose. I feel like we prepared for the worse and took immediate actions. After solving the problem, I believe we were justified in descending from FL190, 75 NM out of detroit to return the aircraft to our maintenance base. Supplemental information from acn 313787: seeing that the cabin was now clear of smoke we decided to continue to detroit willow run which is our maintenance base. A safe continuation to our destination was received in the clearance from ZOB and we landed at willow run with no further incident.

Original NASA ASRS Text

Title: FLC DISTR SMOKE IN COCKPIT.

Narrative: WHILE DSNDING THROUGH FL300 WE STARTED TO SMELL BURNING IN THE CABIN. WE IMMEDIATELY TURNED OFF ALL UNNECESSARY ELECTRICAL EQUIP AND SMELL CONTINUED. DSNDING THROUGH APPROX FL240 SMOKE STARTED FILLING THE CABIN. WE DONNED OXYGEN MASKS AND DROPPED MASKS FOR PAX. I TOLD THE CTLR THAT WE HAD SMOKE IN THE CABIN AND NEEDED LOWER. NOT KNOWING WHAT WAS CAUSING THE PROB, I ASKED THE CTLR WHAT WAS THE NEAREST ARPT TO WHICH HE SAID, 'CLEVELAND.' I SAID THAT INITIALLY I WOULD LIKE TO HEAD FOR CLEVELAND. SOMETIME WHILE THIS WAS TAKING PLACE, WE WERE CLRED TO 12000 FT. AT THIS TIME MY PAX CAME FORWARD AND SAID HE THOUGHT THE SMOKE WAS COMING FROM THE CABIN BLOWER. I LOOKED AT THE FAN SWITCH WHICH IS VERY SMALL IN THE LEAR AND IT WAS ON. I IMMEDIATELY TURNED IT OFF. WITHIN A FEW SECONDS THE SMOKE STOPPED. WE WERE AT FL195. FEELING COMFORTABLE THAT THIS WAS THE PROB, I ASKED THE CTLR FOR FL190 AND RECEIVED IT. THE CABIN RETURNED TO NORMAL AND WE ASKED FOR A CLRNC TO DSND NORMALLY INTO DETROIT AND LAND AT OUR MAINT BASE. NO FURTHER PROBS AROSE. I FEEL LIKE WE PREPARED FOR THE WORSE AND TOOK IMMEDIATE ACTIONS. AFTER SOLVING THE PROB, I BELIEVE WE WERE JUSTIFIED IN DSNDING FROM FL190, 75 NM OUT OF DETROIT TO RETURN THE ACFT TO OUR MAINT BASE. SUPPLEMENTAL INFO FROM ACN 313787: SEEING THAT THE CABIN WAS NOW CLR OF SMOKE WE DECIDED TO CONTINUE TO DETROIT WILLOW RUN WHICH IS OUR MAINT BASE. A SAFE CONTINUATION TO OUR DEST WAS RECEIVED IN THE CLRNC FROM ZOB AND WE LANDED AT WILLOW RUN WITH NO FURTHER INCIDENT.

Data retrieved from NASA's ASRS site as of July 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.