Columbia- Mechanics Course day 3
posted in Columbia |Day 3 was the day at the factory rather than the class-room, which was fun, but in some ways
there were less things for me to report on here. We started with a tour of the aircraft featuring
aerodynamic features, followed by a tour of the factory assembly line and the factory maintenance
center for some demonstrations of fuel set-up and other procedures. I’d had a tour of the assembly
line before but this one was a bit more detailed. They are really focused on moving the line forward
by one step each day to get to their target of delivering 250 airplanes a year. The biggest barrier
to that appears to be that due to the nature of how the composite pieces are created, sometimes things
don’t fit together right initially. Obviously they fix these issues, but the fixes can be time
consuming and can either hold up the line or require that airplane to be moved out to the side.
We saw a number of the special edition Columbia 400s moving down the assembly line. These have a
unique silver and red paint job (including silver paint on the top surfaces), and the full option
package plus a longer warranty and some matched luggage for about $50,000 more than the normal
top-of-the-line price. Seems like a bit much to me, but they do look very cool. Overall the assembly
line was 100% Garmin equipped aircraft at the moment, with mostly 400s but a couple of 350s on the line.
The class on composite repair was pretty interesting. When most pilots think about a composite
aircraft with a huge hole in the end of the wing you assume that will require a complete replacement
of the wing. It turns out that damage to most parts of the aircraft except for the main spars (the
two in the wings and the two down the fuselage) are all repairable. Unlike aluminum where a repaired
part is unlikely to have the same strength as the original, composite repairs are able to build things
back to 100% of the strength it started with.
After that we covered the general electrical system. I learned a couple of interesting things. For
one, I’ve every now and then left cross-tie on and wondered if that was a bad thing. In general there
is no damage you can cause to the system by leaving cross-tie on. There are only two reasons why you
shouldn’t leave it on all the time- first of all, you won’t necessarily be alerted to certain failures
of one bus or the other. Second, some failures (voltage spikes) could in theory damage more of your
aircraft systems if cross-tie is on. So leave it off except for when you test it in pre-flight, but
if you find it on by accident, no big deal. Also, when using ground-power, don’t forget to turn on
cross-tie. The ground-plug only attaches to the left bus, and if you don’t cross-tie, you will wear
down your right battery while charging the left one.
The next presentation was on parts and warranty. For us owners the most interesting point was that
many of the component warranties are different from the Columbia airframe warranty. Apparently they
make this more clear during deliveries now, but when I picked up my airplane I don’t think I realized
that many of my aircraft components were only covered for 1 or 2 years. Since I’m coming up on the two
year point its pretty interesting to discover that my Avidyne and O2 systems are only covered for the
next month.
Finally the Precise Flight folks arrived to speak about the O2 and speed-brake system. Lots of issues
with the speed-brakes happen because they both engage and if each brake doesn’t detect the other one as
fully deployed within 4 seconds, they will retract. If they need lubrication, or your bus voltage is low,
or its very cold out (less than -20C for the 14V systems, less than -30C for the 28V ones), or there is
moisture in the brake-well, it can slow down the deployment and they will pop back. Apparently the
speed-brakes have a drain underneath them and its really important to check that drain and make sure
its dry and not blocked. Otherwise it will accumulate water which will probably freeze at altitude.
Finally if you get slightly asymmetric deployment (they don’t come out at exactly the same time) this
can often be addressed by property lubricating the speed brakes.
One last important note on the speed brakes. Its not in the POH, but they recommended exercising them a
few times on the ground before take-off. This gets the clutches into the right shape for more reliable
deployment in-flight.
I managed to pick up a few interesting tips about the O2 system after the session. First of all they are
coming out with a new flow-meter, the A5. The A5 doesn’t have any real advantages for people who already
have the A4, but it should reduce costs for new purchases. The Precise Flight guys like to run the O2
pressure higher than Mountain High. The Columbia outlet pressure is 25psi and in fact the new system
they designed for the Cirrus is up around 50-60psi. Their conserver system delivers a higher pressure
pulse of Oxygen as you go higher rather than just a longer pulse which they feel provides a more reliable
safe level at higher altitudes.
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