Columbia- Mechanics Course- Hartzell propellers, Garmin, STec Autopilots
posted in Columbia |Today we started with a presentation on the Hartzell propellers used on most of our airplanes. Most of
this wasn’t especially relevant to pilots, but there were a few things I learned. First of all, if its
possible that your airplane was near lightning, you need to inspect the prop for lightning damage during
the pre-flight. Look for little pits in the spinner and/or discoloration on the blade. If you see any
evidence of lightning damage, if its passes certain criteria you are allowed to fly for 10 hours to get
home after which you need to have the propeller torn-down and inspected by a prop-shop. The criteria is
mostly to check for proper operation, such as you do anyway during a run-up, but the representative
from Hartzell said that they want you to call them to talk about it before you go flying. Their 24-hour
phone number for AOG (aircraft on the ground) issues is 937-778-4376. Don’t use this for non-time-critical
issues, but if you have this lightning situation, call them on this number.
I also learned that you should find out if your prop has some balance hardware and it’s a good thing to
look for during the pre-flight if you can.
When cleaning your airplane be very careful not to spray water into the spinner. Basically you should
avoid using anything with pressure to wash the prop area at all. If water gets in there it can be very
bad. Use Stoddard Solvent if needed to remove grease or oil but mostly just use warm soap and water,
and Mothers Auto Polish on the spinner.
We also heard a bit about the future of props. Hartzell recently introduced a composite-construction
prop. These can be very efficient, much lighter weight and are much easier to repair in the case of
damage than a traditional prop. They have an anti-erosion metal edge, which also enables the use of
a hot-prop de-ice system. The only downside is that they are incredibly expensive right now (over $40,000),
but as production ramps up this will likely be the future for high performance aircraft.
A lot of the rest of the day was the representative from Garmin speaking about the G1000 system. Since
I don’t have a G1000 equipped aircraft, this wasn’t as much of a focus for me, but overall the system
seems pretty solid. Currently however there are a set of things that the Avidyne has that the Garmin
doesn’t provide yet. These include support for electronic charts, display of EGT/CHT data on the map
page as data blocks, and ability to download engine data. Those later two are really important to me
as monitoring my engine health is a big confidence booster, both in-flight and at home. The one other
drawback of the system is that if one of your displays fails, you lose ability to use the auto-pilot.
On the other hand, they have the advantage that if either display fails you get the key set of the data
projected onto the remaining one.
One interesting point- the G1000 uses Ethernet to speak between the two displays and to several other
pieces of equipment. Probably a big step up from the RS232 that most avionics have been using so far.
The other big news from the Garmin representative was on the GNS 430 WAAS certification. People have
been waiting on this for a couple of years, but pulling it off has been a bit more difficult that Garmin
expected apparently. They say they are on track for the GNS 430 hardware upgrades to be available in
Q1 2007, but most Avidyne Columbia pilots are going to have a big problem. For the system to be worth
anything, you need a display that can show the glide-slope information and Avidyne just got the data
on how to do that recently. So to be useful in our aircraft, we are going to need a PFD upgrade, and
at the moment the timetable and possible cost of that upgrade are uncertain. I’m looking forward to
getting more details on this from the Avidyne representative tomorrow.
Finally a representative from STec gave us a talk on the auto-pilot used for the non-G1000 Columbias.
The most common reported problem is often porposing which can often be either an issue with the static
system, the altitude transducer or the cable tensions. He mentioned that the cable tensions can be a
common problem and are worth checking at an annual. One debugging technique is to compare the behavior
in ALT (altitude hold) mode vs selecting VS+0 (vertical speed with no speed dialed in). The auto-pilot
operates differently in these two modes and this can help diagnose the issue.
You can also turn down the volume of the alerts. There is a small hole in the right side of the
unit hooked up to a 20 turn potentiometer. 9 full turns counter-clockwise is often just right.
It sure would be nice to not scare my passengers so much every time I turn off the auto-pilot.
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