An effort has been made to keep the DOG Aviation
Blog postings strictly for documenting assembly of the RV-12. However, today’s
post will be stretching that a bit, but hopefully in a good way. Frequent
readers of the DOG Aviation Blog may have noted there have not been any
postings this last week. This is due to having been out of town attending Rotax
912 engine training in Virginia.
The DOG Aviation research department discovered
two Rotax engine training courses were going to be held at the Blue Ridge Community College
in Weyers Cave, Virginia. The first two day class was the
Rotax 912 Service Course; the second two day class was the Rotax Aircraft
Maintenance Course. Both classes were instructed by Dean Vogel, a VERY knowledgeable
representative from Lockwood Aviation in Sebring Florida. As a general rule, these classes
are typically offered in Florida
… seeing that the classes were within a manageable driving distance, decided
to jump on the opportunity to attend the classes in Virginia.
The Blue Ridge Community College has a lovely
campus in a rural Shenandoah Valley setting … with up to par classroom aids such
as computer driven projection screens, variable room lighting, individual
computers at every student’s desk with large displays and Wi-Fi access for
mobile device users. Blue Ridge Community College also has a large hangar a couple of
miles away located at the well maintained Shenandoah Valley Regional
Airport where it offers hands
on career training in aviation maintenance technology.
The first class was the Rotax 912 Service Course
which was split between one day of classroom instruction and one day of at
airport, hands on training working on an airplane with a running Rotax 912
engine to reinforce the classroom instruction. I would whole heartily suggest
RV-12 builders seriously consider taking this class prior to the initial engine
run. It covers those items most important to builders such as best type of
coolant to use for this engine and the procedure for purging air from the cooling
system. Very in depth discussions of the nuts and bolts of the oil system and
the PROPER steps to follow for initial purging of the oil system, along with
the necessary precautions and steps to take for oil tank removal and disassembly
for cleaning and reassembly … not to mention techniques for performing oil and
filter changes that minimize chances for air to get into the system. Also included is trouble shooting techniques
for the old and new ignition modules, ignition trigger coils, etc. Another topic that was discussed in great
detail and demonstrated was setting up the carburetor linkage and synchronization
of the two Bing carburetors using vacuum gauges. A lot more was covered, but that
is the general idea of the big ticket issues covered.
Think you will be driving around the countryside
in the evenings after class just taking in the sights? Think again … there is a
25 question open book test given to you which will take up pretty much the
entire evening sifting through the 912ULS Instillation Manual, 912ULS Line Maintenance
Manual, 912ULS Illustrated Parts Catalog, 912ULS Heavy Maintenance Manual and
of course Service Bulletins. Plus in addition, you will also need to download and
sift through all the above manuals pertaining to the new 912iS Sport engine as
well to correctly answer questions specific to the 912iS Sport. I won’t go into the test
but will say it was much like an FCC test ... in that quite a few questions had one
answer that is totally wrong, one answer that is somewhat plausible, one
answer is for the most part correct, and one answer is more correct. The biggest
hindrance, I believe, had to do with the fact the wording of the questions and answers along
with all the manuals were translated from Austrian … need I say more? At times
it made deciding upon the correct answer interesting. Bottom line … the main point
of the test is getting the student accustomed
to finding where pertinent information is LITERALLY scattered amongst all these
manuals.
The second class was the Rotax Aircraft
Maintenance Course. This class is aimed at getting into the internals of the
engine and gear reduction unit. This class also has a test associated with it
as well and it went easier because of knowing where things are hidden amongst
the manuals. This class was held entirely in the classroom where we
disassembled a 912 engine down to the case and put it back together again using
an array of (expensive) Rotax specialty tools designed to make the job easier
and safe for the engine. Because the crankshaft and connecting rods are one
piece units, Rotax has a policy of authorizing just a few maintenance centers to
carry out work which requires the splitting of the cases and performing bottom
end checks or repairs. As such, the Aircraft Maintenance Course only covers
from the crankcase up …. valves, rocker arms, valve pushrods, cylinder heads,
cylinders, pistons, rings, piston pins, water pump, oil pump, generator along with the
gear reduction unit for the propeller. Also covered was complete disassembly and
inspection of the Bing carburetor and all its internal goodies.
In all honesty, unless you are a mechanic or
have a working knowledge of gas engines, this class is not for the average Joe.
However, for the average Joe who wants to perform the mandatory 200 hour
teardown inspection of the Bing carburetors and learn know to decipher normal
wear from a potential big problem and then successfully reassemble the carburetors
…. the cost of this course will practically pay for itself at the first 200
hour inspection. One thing was quite apparent, when looking at carburetor parts
taken off engines that were running out of sync for long periods of time … the
parts wear in the carburetors was dramatic. During the first class we took the carburetors out
of sync to see the difference in the vacuum gauge readings …. have to say, with
the carburetors out of sync, the entire engine shakes like a wet dog.
In summary:
Have nothing but praise regarding my experience with the Blue Ridge
Community College in Weyers Cave Virginia
and Dean Vogel from Lockwood Aviation ... it was a nice location to conduct this training (although lunch choices
in the vicinity are extremely limited) and Dean has a plethora of Rotax 912 experience and information. For the average RV-12 builder, setting
up the carburetors correctly is paramount to long term trouble free Rotax 912 operation ... as is learning the nuances of the Rotax 912 oil system. This engine DOES
NOT tolerate a loss of engine oil, the internal tolerances are just way too
close to run more than a few seconds without damage. So between learning to correctly
purge the oil system of air and synchronization of the carburetors for a smooth
running engine … highly recommend RV-12 builders seriously consider taking the Rotax
912 Service Course. The cost of the course is a good insurance policy
considering the huge expense for the high tech little engine.
Attending the Rotax Aircraft Maintenance Course
is a judgment call. RV-12 builders who will not be working on their Rotax 912 engine or not
performing the 200 hour teardown inspections of the two Bing carburetors will
gain little value from this course … unless you just want to know about the
inner workings of the engine for general knowledge.
On a personal note: Friday afternoon after the
last class was over, I drove down to Williamsburg, VA to visit with RV-12
builders John and Dick who are frequent visitors to the DOG Aviation Blog. John
and Dick are hangar mates and together they decided to partner up and build an
RV-12. Knowing I was going to be in Virginia, John invited me to come down to visit
them and have a look at their RV-12 project … so decided to make the two hour
drive to Williamsburg and pay them a visit. Glad I did, both John and Dick were a
pleasure to meet and we had a great time discussing all things RV-12.
Amazingly, they have only been at it since March and have, for the most part,
caught up to the stage of construction the DOG Aviation RV-12 is at now. They have
been spending some long days at it and it shows with all the good progress.
Thanks for all the southern hospitality guys. Hopefully the next visit will be
by air and not car.
