Key Locks -- Part II

After reading the other posts about key locks, the responses brought another
question to mind.

My key ignition switch works very hard, and the key can be removed in any
position. It's hard to push it in and keep the starter engaged (it's one
of those turn-while-you-push switches), so we usually end up pushing it
several times to get the engine started.

Can that ignition switch be dismantled and repaired, or is this a
"replace-only" job?
--
Jay Honeck
Iowa City, IA
Pathfinder N56993
www.AlexisParkInn.com
"Your Aviation Destination"

Jay Honeck wrote:
: Can that ignition switch be dismantled and repaired, or is this a
: "replace-only" job?
: --

Unlikely to be repairable without some questionable dissasembly. Those
switches are usually made with little metal tabs bent to hold on the back plate
insulator. The tabs have to be be unbent to remove, and then rebent to reinstall.
There's probably some impressive spring assembly in there, as well (to take care of
the rotational spring, and the push-in spring).

-Cory

--

************************************************** ***********************
* Cory Papenfuss *
* Electrical Engineering candidate Ph.D. graduate student *
* Virginia Polytechnic Institute and State University *
************************************************** ***********************

Jay Honeck wrote:

Can that ignition switch be dismantled and repaired, or is this a
"replace-only" job?

I had a similar problem with mine (the key would actually FALL OUT)
in flight and it would appear to be in the OFF position and still
leave one MAG hot. I just replaced the blasted thing. A new bendix
switch wasn't that much. My ignition key didn't match the canopy
or baggage compartment locks anyhow.

I had a similar problem with mine (the key would actually FALL OUT)
in flight and it would appear to be in the OFF position and still
leave one MAG hot. I just replaced the blasted thing. A new bendix
switch wasn't that much. My ignition key didn't match the canopy
or baggage compartment locks anyhow.

Now, for the real question:

Do I have to get this part from Piper (for big $$$), or can I use the
(apparently identical) switch shown in the Aircraft Spruce catalog?
--
Jay Honeck
Iowa City, IA
Pathfinder N56993
www.AlexisParkInn.com
"Your Aviation Destination"

Jay,
If the part is TSO or PMA with equiv part number it is fine.....
Michelle


Jay Honeck wrote:

After reading the other posts about key locks, the responses brought another
question to mind.

My key ignition switch works very hard, and the key can be removed in any
position. It's hard to push it in and keep the starter engaged (it's one
of those turn-while-you-push switches), so we usually end up pushing it
several times to get the engine started.

Can that ignition switch be dismantled and repaired, or is this a
"replace-only" job?

You may actually have an AD that requires you to replace the mag
switch. I had to replace mine two years ago after a shop showed me an
AD that says it must be replaced if the key can be removed in flight. I
have no idea why the hell such an AD exists.
-Robert

It must have a TSO or STC. If the TSO lists your aircraft then you are
good to go. I would be surprised if this isn't the case.
-Robert

I was trying to remember just what that AD was about. I remember reading it
a couple years ago, but do not know why. Wasn't there something in the AD
about the switch malfunctioning and actually leaving one or both mags hot
when the switch was turned to off in addition to the key comeing out? Seems
like I also remember an inspection and lubrication requirement.

Maybe I was just dreaming.

Jim

"Robert M. Gary" wrote in message
ups.com...
You may actually have an AD that requires you to replace the mag
switch. I had to replace mine two years ago after a shop showed me an
AD that says it must be replaced if the key can be removed in flight. I
have no idea why the hell such an AD exists.
-Robert

There also was a part of that AD that required an operational test in
which the key is forcefully (no torque spec but plenty aggressively)
turned CCW beyond OFF to see if the engine keeps running. Some
aircraft including our 172M, would relight again.

A new switch wasn't that expensive about 5 years ago (like $100). It
came as part of a kit replacing all of the locks in the airframe. The
tumbler setup and key etc was more robust that the Cessna OEM key.

AH!! That's where I read it... when studying for my CFI ride in a 182RG.
Thanks!
Jim

"nrp" wrote in message
ps.com...
There also was a part of that AD that required an operational test in
which the key is forcefully (no torque spec but plenty aggressively)
turned CCW beyond OFF to see if the engine keeps running. Some
aircraft including our 172M, would relight again.

A new switch wasn't that expensive about 5 years ago (like $100). It
came as part of a kit replacing all of the locks in the airframe. The
tumbler setup and key etc was more robust that the Cessna OEM key.