North&Wing&S,LSA&Maintenance&Manual&
Model:&Sport&X2&582&
Issue 3.2
Printed: July 16 2017
Page 94
the failure of only one switch will allow the engine to continue running on that ignition
system, and without special tools, it is not obvious which switch has failed. The table below
shows the results of different combinations of switch positions and conditions.
For Pilot Switches Only:
Pilot Switches
Results
Ign. A
Ign. B
On
On
Engine runs on both ignition systems
On
Off
Engine runs on Ignition system A only
Off
On
Engine runs on ignition system B only
Off
Off
Engine will not run
Fails Open
Off
Engine runs on ignition system A only
Off
Fails open Engine runs on ignition system B only
In this case the only way to shut the engine down with a failed switch is to either choke it or, if
possible, starve it by pinching the fuel line until the engine stops. Fuel shut offs are not
provided on North Wing aircraft because of the high probability of someone forgetting to open
it but still having enough fuel in the carburetor to get off the ground.
With Instructor Switches Installed:
Pilot Switches
Instructor Switches
Results
Ign. A
Ign. B
Ign. A
Ign. B
On
On
On
On
Engine runs on both ignition
systems
On
Off
Off
Off
Engine will not run
Off
Off
On
On
Engine will not run
On
Off
On
Off
Engine runs on ignition system A
only
Fails
Open
Off
On
On
Engine runs on ignition system A
only
Off
Fails Open
On
On
Engine runs on ignition system B only
Off
Fails Open
On
Off
Engine will not run
Note that with the instructor switches installed, the ignition system with the failed switch can
still be turned off unless the failure is in the leads coming from the engine to the Hot Box. A
properly functioning “OFF” position overrides the ON position because it is able to ground out
the ignition coil, thereby making that ignition coil inoperable.
Once the engine is stopped, trace the ground and yellow coil wiring to the mag switches using
an Ohm meter or continuity meter to assure they are indeed grounded when the mag switch is
in the OFF position. Locate and repair the break in the ground circuit.