Narrative:

My wkend job is towing banners. The stinson I fly has a 190 hp lycoming O435 and a variable pitch hartzell propeller. Oil capacity is 12 quarts. Chain of events: I had just picked up a 30 ft by 80 ft panel banner and was about 5 mi northwest of lgb airport. My altitude was approximately 1000 ft when I caught a faint whiff of something burning. The smell was particularly difficult to recognize, so I moved the fresh air vent (located on the passenger side window) to draw air from outside the aircraft. I reasoned that this might aid in troubleshooting if the smell was inside or outside the aircraft. As soon as I moved the vent, the smell intensified and as I looked forward I noticed what looked like the beginning of an engine fire. Elapsed time approximately 10 seconds. I immediately turned towards the airport (lgb) and made a radio call to announce I was turning around for a landing. Tower responded saying that I was unreadable. Tower then cleared me for a frequency change, probably assuming that I wanted one. By this time, large clumps of sludge were sticking to the windscreen, and there was a great deal of smoke coming from the cowl and beginning to fill the cockpit. As I looked for a possible landing site, I radioed the tower declaring an emergency. As I was making the call to tower, my windshield became covered with oil and the cockpit filled with smoke. Tower returned my transmission saying I was unreadable. I figured that maybe oil was covering the antenna. I then squawked 7700. My visibility had become limited to a portion of the side windows and down out of my now opened pilot side door. I moved the fresh air vent to suction the smoke out of the cockpit. As I continued towards the airport, I realized that I would not be able to make it with the banner attached. An off-field landing was out of the question due to my very limited visibility. The engine continued to run although my manifold pressure, RPM's, and oil pressure were rapidly decreasing. I maneuvered the aircraft over an industrial complex just to my left and released the banner. My intentions were to drop the banner in the industrial area, and I accounted for possible wind drift. It is my knowledge that the banner was recovered 2 days after the incident. Upon releasing the banner, I became hopeful of reaching the airport safely. I'm not exactly sure of my altitude at that point, but it was below 800 ft. I believe I radioed lgb one more time to announce my intentions of landing on runway 16L (inactive at the time). I shut down and secured the engine shortly after dropping the banner and commenced a power-off glide to runway 16L. In preparation for the landing, I also shut off the master switch and tightened my seatbelts real tight. As I crossed over runway 25R (active at the time), I noticed an aircraft departing below me. My altitude was about 100-150 ft, but I don't believe there was a threat of collision. My forward visibility was still completely obscured by the oil soaked windscreen. Luckily, the wind was blowing right down the runway (another reason for landing on runway 16L). Looking out the side window, I safely brought the aircraft to rest on the runway between active runways. I did not have enough speed to exit the runway. When the aircraft stopped, I unbuckled, grabbed my lunch, and ran clear of the plane. The emergency crews arrived a few mins later. What happened? Oil was found from the propeller area running all the way back to the tail feathers. Further inspection revealed a severely damaged jack plate on the propeller. Apparently, the bearings in the spinner plate had somehow broken. When this happened, the spinner plate ground through the jack plate located behind it. This generated an incredible amount of heat which subsequently burned the oil bladder located behind the jack plate. I don't know why this happened, and there was nothing noticeable during my preflight.

Related reports:

Google
 

Original NASA ASRS Text

Title: PLT OF A STINSON, TOWING A BANNER, DROPPED HIS BANNER AND RETURNED TO DEP ARPT DUE TO SMOKE COMING FROM THE ENG OR PROP AND OIL COVERING THE WINDSHIELD.

Narrative: MY WKEND JOB IS TOWING BANNERS. THE STINSON I FLY HAS A 190 HP LYCOMING O435 AND A VARIABLE PITCH HARTZELL PROP. OIL CAPACITY IS 12 QUARTS. CHAIN OF EVENTS: I HAD JUST PICKED UP A 30 FT BY 80 FT PANEL BANNER AND WAS ABOUT 5 MI NW OF LGB ARPT. MY ALT WAS APPROX 1000 FT WHEN I CAUGHT A FAINT WHIFF OF SOMETHING BURNING. THE SMELL WAS PARTICULARLY DIFFICULT TO RECOGNIZE, SO I MOVED THE FRESH AIR VENT (LOCATED ON THE PAX SIDE WINDOW) TO DRAW AIR FROM OUTSIDE THE ACFT. I REASONED THAT THIS MIGHT AID IN TROUBLESHOOTING IF THE SMELL WAS INSIDE OR OUTSIDE THE ACFT. AS SOON AS I MOVED THE VENT, THE SMELL INTENSIFIED AND AS I LOOKED FORWARD I NOTICED WHAT LOOKED LIKE THE BEGINNING OF AN ENG FIRE. ELAPSED TIME APPROX 10 SECONDS. I IMMEDIATELY TURNED TOWARDS THE ARPT (LGB) AND MADE A RADIO CALL TO ANNOUNCE I WAS TURNING AROUND FOR A LNDG. TWR RESPONDED SAYING THAT I WAS UNREADABLE. TWR THEN CLRED ME FOR A FREQ CHANGE, PROBABLY ASSUMING THAT I WANTED ONE. BY THIS TIME, LARGE CLUMPS OF SLUDGE WERE STICKING TO THE WINDSCREEN, AND THERE WAS A GREAT DEAL OF SMOKE COMING FROM THE COWL AND BEGINNING TO FILL THE COCKPIT. AS I LOOKED FOR A POSSIBLE LNDG SITE, I RADIOED THE TWR DECLARING AN EMER. AS I WAS MAKING THE CALL TO TWR, MY WINDSHIELD BECAME COVERED WITH OIL AND THE COCKPIT FILLED WITH SMOKE. TWR RETURNED MY XMISSION SAYING I WAS UNREADABLE. I FIGURED THAT MAYBE OIL WAS COVERING THE ANTENNA. I THEN SQUAWKED 7700. MY VISIBILITY HAD BECOME LIMITED TO A PORTION OF THE SIDE WINDOWS AND DOWN OUT OF MY NOW OPENED PLT SIDE DOOR. I MOVED THE FRESH AIR VENT TO SUCTION THE SMOKE OUT OF THE COCKPIT. AS I CONTINUED TOWARDS THE ARPT, I REALIZED THAT I WOULD NOT BE ABLE TO MAKE IT WITH THE BANNER ATTACHED. AN OFF-FIELD LNDG WAS OUT OF THE QUESTION DUE TO MY VERY LIMITED VISIBILITY. THE ENG CONTINUED TO RUN ALTHOUGH MY MANIFOLD PRESSURE, RPM'S, AND OIL PRESSURE WERE RAPIDLY DECREASING. I MANEUVERED THE ACFT OVER AN INDUSTRIAL COMPLEX JUST TO MY L AND RELEASED THE BANNER. MY INTENTIONS WERE TO DROP THE BANNER IN THE INDUSTRIAL AREA, AND I ACCOUNTED FOR POSSIBLE WIND DRIFT. IT IS MY KNOWLEDGE THAT THE BANNER WAS RECOVERED 2 DAYS AFTER THE INCIDENT. UPON RELEASING THE BANNER, I BECAME HOPEFUL OF REACHING THE ARPT SAFELY. I'M NOT EXACTLY SURE OF MY ALT AT THAT POINT, BUT IT WAS BELOW 800 FT. I BELIEVE I RADIOED LGB ONE MORE TIME TO ANNOUNCE MY INTENTIONS OF LNDG ON RWY 16L (INACTIVE AT THE TIME). I SHUT DOWN AND SECURED THE ENG SHORTLY AFTER DROPPING THE BANNER AND COMMENCED A PWR-OFF GLIDE TO RWY 16L. IN PREPARATION FOR THE LNDG, I ALSO SHUT OFF THE MASTER SWITCH AND TIGHTENED MY SEATBELTS REAL TIGHT. AS I CROSSED OVER RWY 25R (ACTIVE AT THE TIME), I NOTICED AN ACFT DEPARTING BELOW ME. MY ALT WAS ABOUT 100-150 FT, BUT I DON'T BELIEVE THERE WAS A THREAT OF COLLISION. MY FORWARD VISIBILITY WAS STILL COMPLETELY OBSCURED BY THE OIL SOAKED WINDSCREEN. LUCKILY, THE WIND WAS BLOWING RIGHT DOWN THE RWY (ANOTHER REASON FOR LNDG ON RWY 16L). LOOKING OUT THE SIDE WINDOW, I SAFELY BROUGHT THE ACFT TO REST ON THE RWY BTWN ACTIVE RWYS. I DID NOT HAVE ENOUGH SPD TO EXIT THE RWY. WHEN THE ACFT STOPPED, I UNBUCKLED, GRABBED MY LUNCH, AND RAN CLR OF THE PLANE. THE EMER CREWS ARRIVED A FEW MINS LATER. WHAT HAPPENED? OIL WAS FOUND FROM THE PROP AREA RUNNING ALL THE WAY BACK TO THE TAIL FEATHERS. FURTHER INSPECTION REVEALED A SEVERELY DAMAGED JACK PLATE ON THE PROP. APPARENTLY, THE BEARINGS IN THE SPINNER PLATE HAD SOMEHOW BROKEN. WHEN THIS HAPPENED, THE SPINNER PLATE GROUND THROUGH THE JACK PLATE LOCATED BEHIND IT. THIS GENERATED AN INCREDIBLE AMOUNT OF HEAT WHICH SUBSEQUENTLY BURNED THE OIL BLADDER LOCATED BEHIND THE JACK PLATE. I DON'T KNOW WHY THIS HAPPENED, AND THERE WAS NOTHING NOTICEABLE DURING MY PREFLT.

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.