Ignition switch settings

Right magneto is "hot" (ungrounded). The "OFF" position grounds
both
mags.


I know from personal experience that a lot of pilots continue to have
serious misconceptions about such things, but it still bothers me. This
is
the sort of thing that is part of every run-up, and therefore should
have
been part of the aircraft systems knowledge requirement to get the
license--not necessarily the grounding issue, but which magneto actually
fires its set of plugs.



I don't get the connection. Why would the licenced pilot need to know
which
mag and which set of plugs is firing on Left or Right key position? Know
why
the mag check is important and what to watch for during the mag check,
yes.


No, but he should know that that the Right mag is hot (firing plugs) and the
Left mag is cold (not firing) when the switch is in the "R" position, and
that the Right mag is cold (not firing) and the Left mag is hot (firing
plugs) when the switch is in the "L" position. That much systems knowledge
would seem usefull for a safe and reasonable Go/NoGo decision prior to
take-off, and also to explain a problem to an efficient manner.

Knowledge of the specifics of how the ignition system works could be very
usefull in the case of "stealing your oun airplane" because you lost the key
at a remote hunting/fishing spot; but I can not imagine that being part of
an accredited licensing test.

Peter

"Peter Dohm" wrote in message ...
:
: No, but he should know that that the Right mag is hot (firing plugs) and the
: Left mag is cold (not firing) when the switch is in the "R" position, and
: that the Right mag is cold (not firing) and the Left mag is hot (firing
: plugs) when the switch is in the "L" position. That much systems knowledge
: would seem usefull for a safe and reasonable Go/NoGo decision prior to
: take-off, and also to explain a problem to an efficient manner.
:
: Knowledge of the specifics of how the ignition system works could be very
: usefull in the case of "stealing your oun airplane" because you lost the key
: at a remote hunting/fishing spot; but I can not imagine that being part of
: an accredited licensing test.
:
: Peter
:
:

But they sure as heck should know that turning off the master switch will not turn off their engine.

There are some old engines that did use battery power for
the ignition and in those, the battery master must be on.
But, in general aircraft built in the post WWII period have
two independent magnetos and the battery is used for lights,
starting and radios, etc. Some aircraft had one magneto and
one coil/distributor [like a car], so the AFM/POH should be
read. Also ignition operation should be checked on the
ground as part of the pre or post-flight checklists.



"Blueskies" wrote in message
t...
|
| "Peter Dohm" wrote in message
...
| :
| : No, but he should know that that the Right mag is hot
(firing plugs) and the
| : Left mag is cold (not firing) when the switch is in the
"R" position, and
| : that the Right mag is cold (not firing) and the Left mag
is hot (firing
| : plugs) when the switch is in the "L" position. That
much systems knowledge
| : would seem usefull for a safe and reasonable Go/NoGo
decision prior to
| : take-off, and also to explain a problem to an efficient
manner.
| :
| : Knowledge of the specifics of how the ignition system
works could be very
| : usefull in the case of "stealing your oun airplane"
because you lost the key
| : at a remote hunting/fishing spot; but I can not imagine
that being part of
| : an accredited licensing test.
| :
| : Peter
| :
| :
|
| But they sure as heck should know that turning off the
master switch will not turn off their engine.
|
|

"Jim Macklin" wrote in message ...
: There are some old engines that did use battery power for
: the ignition and in those, the battery master must be on.
: But, in general aircraft built in the post WWII period have
: two independent magnetos and the battery is used for lights,
: starting and radios, etc. Some aircraft had one magneto and
: one coil/distributor [like a car], so the AFM/POH should be
: read. Also ignition operation should be checked on the
: ground as part of the pre or post-flight checklists.
:
:
:

How old are you talking, Jim? Any specifics? Engine, airframe?