DutchessFlier
Line Up and Wait
O-360-A3A AirPlains 180 Conversion
Slick Mags New in 2005 now with 300hrs
Flew last week:
Cold AM start/runup/mag check fine-2 hour flight-shutdown for about 2 hrs.
Restart to leave:
Statup fine (3 blades) Running a bit rough: Decided to do a Mag Check on the ramp at about 1000RPMs: Rt Mag fine-75RPM drop/ On Lt Mag No Spark at all??? / Key Back to Both to not stall the engine.
Repeated the above a few times with the same result.
Avionics Off / Master Off then On (I know it has no relationship to the Mags) cycled through carb heat, etc. etc.
Repeated the Mag Check: Now everything is totally fine! 75RPM drop on each mag, smooth running at 600/1200/2200 RPMs on each mag and on both mags.
Taxi over to an open part of the ramp: Shutdown for 5 mins and restarted. Ran bout 10 runups and mag checks various RPMs-no problems. Wiggled the key around in the ignition switch in each position to see if the switch itself was an issue.
Decided to fly home: VFR day, plenty of airports enroute if we had to land. One more runup and mag check at the hold line. Uneventful flight, and an in-flight mag check was also fine.
Next day, out to the plane on the home ramp. Started up and another 15 or so mag checks, etc. No issues at all....
The ignition switch was serviced to meet the AD that was out in 1993. The mags also fall under an SB from Unison SB3-08 regarding carbon brush wear, but no evidence of that was found at last annual in December.
Looked for evidence of chafing and any loose connections on the leads, none found.
Any thoughts?
Slick Mags New in 2005 now with 300hrs
Flew last week:
Cold AM start/runup/mag check fine-2 hour flight-shutdown for about 2 hrs.
Restart to leave:
Statup fine (3 blades) Running a bit rough: Decided to do a Mag Check on the ramp at about 1000RPMs: Rt Mag fine-75RPM drop/ On Lt Mag No Spark at all??? / Key Back to Both to not stall the engine.
Repeated the above a few times with the same result.
Avionics Off / Master Off then On (I know it has no relationship to the Mags) cycled through carb heat, etc. etc.
Repeated the Mag Check: Now everything is totally fine! 75RPM drop on each mag, smooth running at 600/1200/2200 RPMs on each mag and on both mags.
Taxi over to an open part of the ramp: Shutdown for 5 mins and restarted. Ran bout 10 runups and mag checks various RPMs-no problems. Wiggled the key around in the ignition switch in each position to see if the switch itself was an issue.
Decided to fly home: VFR day, plenty of airports enroute if we had to land. One more runup and mag check at the hold line. Uneventful flight, and an in-flight mag check was also fine.
Next day, out to the plane on the home ramp. Started up and another 15 or so mag checks, etc. No issues at all....
The ignition switch was serviced to meet the AD that was out in 1993. The mags also fall under an SB from Unison SB3-08 regarding carbon brush wear, but no evidence of that was found at last annual in December.
Looked for evidence of chafing and any loose connections on the leads, none found.
Any thoughts?