The SR22 began life as a wonderfully advanced aircraft, in general aviation terms. It
had mostly composite construction, the latest avionics, and great ergonomics. Since
then, we have enjoyed several generations of the SR22, each with some level of
advancement to the extent that economics and the FAA have allowed. The latest
iteration is the G7, which has some impressive upgrades as well as some more routine
upgrades. It has been my life experience that every solution (improvement) comes with
its own new set of problems. The cool new G7 starter switch is a good example.
Sometimes upgrades are a lot about style and not so much about substance. Cirrus
changed to a new ignition/starter switch arrangement that looks very nice but
operationally and technically, it isn’t a big change. The basic ignition switch is still there
but is just hidden behind some extra complication and a modern new knob. The start
switch, however, is actually a completely different part and is the component that is
giving some trouble.
The problem presents when the start button is pushed and absolutely nothing happens.
Two or three pushes later the starter engages and the prop turns. With some
experience the first push and a little wiggle will get it to engage on first try. Not a safety
of flight issue, but certainly not what one wants on a new airplane. Cirrus’ solution is to
install a new switch under warranty. Easy enough to say, although much more involved
to accomplish.
The new push-button switch
Access to this switch for replacement requires significant disassembly of the instrument
panel. It begins with disconnecting the ship’s new EarthX battery which is mounted
forward of and below the MFD. This is a change from the earlier SR22 models with the
much larger battery mounted on the forward side of the firewall. The right underside
kick panel must be removed so the battery can be disconnected during replacement of
the starter switch.
Next is the removal of the PFD and the whole left side instrument panel. This isn’t
terribly difficult but requires nerves of steel as the technician must avoid making any
marks on the beautiful new instrument panel and related interior. Now that half of the
panel is out and sitting on a work bench, the simple task of replacing the actual switch
can begin.
The left side panel fully removed
The removed section of the panel with the switch assembly
I haven’t mentioned that a special tool must be fabricated to remove the nut that holds
the switch into its mount. It isn’t high tech and only has to be fabricated once for use on
all subsequent switch replacements.
The special tool
There are only four wires attached to the switch. Each wire is cut from the old switch
and soldered to the new switch one at a time. After all are soldered in place and the
retaining nut installed with the fancy new tool, the assembly should be tested. I’m a
serious advocate for testing such work as it goes along to not be surprised at the end to
find the new switch is bad. Reassembly is basically the reverse of the disassembly with
all the same care to avoid damage to the upholstery or instrument panel.
A wooden block with a custom fit hole made to hold the housing during the nut removal
Finally, the nut removed and the switch liberated from the housing
The above process is what is called out in the service manual for switch replacement.
After performing this the first time by the book, some easy work arounds were found.
The work arounds reduce the labor time, which is nice for the shop, and more
importantly less disassembly is required. Less disassembly means less opportunity to
make a mistake. The next time around we’ll know how to bring the old switch out of its
mount without removing the entire left side instrument panel structure. Experience says
that sometimes you must live it to learn it.
To those of you that have a new G7, watch for the intermittent start switch. If it goes
bad, it won’t cause the plane to fall out of the sky, but it might be a frustration until you
can get it to your shop for replacement. Until then, just try a little push and wiggle until
the prop turns and hold on till the engine starts.
© Paul New 2024
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