Narrative:

I departed salinas airport on runway 26, during VMC at approximately XA45 local time. After takeoff, gear up, checking for normal indications and trimming the aircraft for climb, I turned to a heading of 020 degrees with the intent of landing at 3o7 some 17 mi away. As I was climbing at 100 KTS, I heard incoming traffic contact the tower on a flight path that would intersect my flight path. To avoid any conflict, I increased my climb angle to vy (best rate) and continued on course. Approximately 3 mins after takeoff, the engine ceased making power, and the RPM's dropped from 2700 RPM to about 1800 RPM. All other gauges were within their normal parameters. Fuel pressure was normal, oil pressure was normal, cht and oil temperatures were normal. I pushed the nose down to establish a descent at v-glide (100 mph), turned to the right toward salinas airport, and notified the tower I had lost power and would be returning to the field. After I switched fuel tanks, and cycled the fuel boost pump on and off, with no effect on the engine, I declared an emergency. The salinas tower cleared me to land on runway 26, which I did without event. Upon coasting to the ramp, and securing the aircraft, I exited the aircraft and pushed it to the transient parking area. A postflt check revealed a minor amount of fuel draining from the manifold overflow/breather line, and a minor (but more than typical) amount of oil on and around the nosewheel. The oil level was normal. I turned the propeller by hand. The engine had good compression, however I was unable to hear the magneto impulse coupling 'click' as I cranked the engine. It was later determined that the magneto separated from the engine.

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Original NASA ASRS Text

Title: A MOONEY 20J IN CLB AT 3500 FT RETURNED TO LAND DUE TO LOSS OF ENG PWR. CAUSED BY THE 'DUPLEX' MAGNETO SEPARATING FROM THE ENG.

Narrative: I DEPARTED SALINAS ARPT ON RWY 26, DURING VMC AT APPROX XA45 LCL TIME. AFTER TKOF, GEAR UP, CHKING FOR NORMAL INDICATIONS AND TRIMMING THE ACFT FOR CLB, I TURNED TO A HDG OF 020 DEGS WITH THE INTENT OF LNDG AT 3O7 SOME 17 MI AWAY. AS I WAS CLBING AT 100 KTS, I HEARD INCOMING TFC CONTACT THE TWR ON A FLT PATH THAT WOULD INTERSECT MY FLT PATH. TO AVOID ANY CONFLICT, I INCREASED MY CLB ANGLE TO VY (BEST RATE) AND CONTINUED ON COURSE. APPROX 3 MINS AFTER TKOF, THE ENG CEASED MAKING PWR, AND THE RPM'S DROPPED FROM 2700 RPM TO ABOUT 1800 RPM. ALL OTHER GAUGES WERE WITHIN THEIR NORMAL PARAMETERS. FUEL PRESSURE WAS NORMAL, OIL PRESSURE WAS NORMAL, CHT AND OIL TEMPS WERE NORMAL. I PUSHED THE NOSE DOWN TO ESTABLISH A DSCNT AT V-GLIDE (100 MPH), TURNED TO THE R TOWARD SALINAS ARPT, AND NOTIFIED THE TWR I HAD LOST PWR AND WOULD BE RETURNING TO THE FIELD. AFTER I SWITCHED FUEL TANKS, AND CYCLED THE FUEL BOOST PUMP ON AND OFF, WITH NO EFFECT ON THE ENG, I DECLARED AN EMER. THE SALINAS TWR CLRED ME TO LAND ON RWY 26, WHICH I DID WITHOUT EVENT. UPON COASTING TO THE RAMP, AND SECURING THE ACFT, I EXITED THE ACFT AND PUSHED IT TO THE TRANSIENT PARKING AREA. A POSTFLT CHK REVEALED A MINOR AMOUNT OF FUEL DRAINING FROM THE MANIFOLD OVERFLOW/BREATHER LINE, AND A MINOR (BUT MORE THAN TYPICAL) AMOUNT OF OIL ON AND AROUND THE NOSEWHEEL. THE OIL LEVEL WAS NORMAL. I TURNED THE PROP BY HAND. THE ENG HAD GOOD COMPRESSION, HOWEVER I WAS UNABLE TO HEAR THE MAGNETO IMPULSE COUPLING 'CLICK' AS I CRANKED THE ENG. IT WAS LATER DETERMINED THAT THE MAGNETO SEPARATED FROM THE ENG.

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.