ACRONYM ANOMALIES by Sam Longo AME A&P
Have you ever stopped to notice how often you use acronyms on a daily basis? “Yesterday I dropped into HMV to pick up a few CD’s and DVD’s. Driving home in my SUV, I decided to get some KFC, got lost while checking my GPS and side-swiped a truck from UPS!”
Although acronyms are really starting to go mainstream in our everyday vocabulary, they have always been a mainstay in the language of aviation. Though it is not common knowledge, even the word acronym is in fact an acronym. It stands for, ABREVIATED, CONFUSING, RARELY, OBVIOUS, NAMES, YOU, MAKE, simply because you are to lazy to write the whole thing. The lists of aviation acronyms for parts, products and systems can be overwhelming and often confusing. We strive to learn them all but the list just continues to grow. The industry barely gets a new name out and it is immediately acronomized. The new Honda Jet is a good example. The very light jet has already become a VLJ!
When I was a teenager (many years ago) my first sports car was, a well used, 1962 MG Midget. When I purchased the car I remember that my father was horrified. “You could have gotten a nice dependable American car!” he said. In his opinion, MG simply stood for ”miles of grief.” Sure enough, keeping the little car going was a full time job. The first time it wouldn’t start posed a bit of a problem. I couldn’t figure out how to open the damn hood. I finally realized that the little knob under the dash with the “B” on it stood for bonnet and so my education into acronyms and British sports car nomclementure began. Soon I was, popping the bonnet, opening the boot, and fetching my spanners to replace brushes in the dynamo. Ah yes the dynamo…obviously the “Prince of Darkness” Mr. Lucas himself, didn’t have the nerve or the confidence to actually call it a generator! Hence the motto of all British car and motorcycles enthusiasts world wide, “Get home before dark!” After all the lights were controlled by the even more famous, three- position, Lucas toggle switch…dim, flicker, and off!
Speaking of generators and getting back to the topic of aviation, the modern flying machine is an acronomic nightmare. The generator is now a CSD (constant speed drive) or an IDG (integral drive generator). The engines have FADEC (full authority digital engine control), to command the FCU (fuel control unit) and VIGV’s (variable inlet guide vanes). You need not worry if your EGT (exhaust gas temperature) is too high or your EPR (engine pressure ratio) is too low. Simply do an HSI (hot section inspection) to check out the engines condition. If you find a crack, no problem, we can check it out with NDT (non destructive testing). If the part turns out to be NFG (no freaking good) we can order a new one AOG (aircraft on ground) and have you flying ASAP (as soon as possible). As you can see this acronym thing is OOC (out of control)!
Recently in the engine overhaul shop at Centennial College, a student asked a question while doing a bulk inspection of a Lycoming engine. It concerned the inside diameter of the shaft bearings of the crankshaft. The table of limits stated: “diameter must be concentric with main bearing within .003 inch TIR”. “What is TIR?” they asked. Fortunately it was coffee break (saved by the bell) so my fellow instructor and I looked it up on his computer. In aviation acronyms alone we found over thirty possibilities. Luckily we quickly narrowed it down to the only logical choice (total indicated runout). Never the less it was a real eye opener!
Another interesting acronym misadventure, was trying to determine the meaning of the RSA fuel injection system. This system has been around for a while and is still used on many piston engine aircraft today. I finally found the answer in an old RCAF (Royal Canadian Air Force) training manual. This system uses a stem assembly and poppet valve to control fuel flow. The stem is connected to an air diaphragm and a fuel diaphragm, each regulated by two air pressures and two fuel pressures respectively, hence the name RSA (regulated stem assembly).
Fortunately for me, those early days with the MG Midget were not so complicated. It was a relatively simple car to work on and was a great way to learn the secrets of basic maintenance. I sealed the leaky petrol tank with PRC (Product Research Company), topped up the SU carburetors (Skinners Union) with ATF (automatic transmission fluid) and lubricated the linkages and cables with WD40 (water dispersant, formula #40). I re-sealed the rocker cover with RTV (room temperature vulcanized) and filled up the crankcase with oil and STP (scientifically treated petroleum). Afterward, that little MG Midget ran like a clock. MG? We all know that one stands for Morris Garages. However, as stated earlier, acronyms can often have many different definitions. As a nineteen year old, high school kid, MG had only one meaning that mattered… more girls. In my rusty recollection, a very accurate acronym, indeed!