Sunday, June 7, 2015

Week In Review – Rotax 912 Training

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.