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Aviation Safety


Dave Fry, WVFC CFI and Aviation Safety Counselor


Rust and Full-down Autorotations


For most of us rust is something we don’t want. Whether it’s in the form of Fe2O3or the kind that appears on the leaves of your favorite rose, it’s not good.  Depending upon what the rust appears on and the depth of the rust, it can be even worse – it can affect the strength or even the life of the “host”.


When flying accumulates rust, it’s Not Good. It can result in sloppy performance, poor muscle memory, questionable judgment, and a reduced ability even to see the differences between what you want and what you have, to say nothing of the ability to perform at your previous level.


Having not flown a helicopter for about four years, I decided that a systematic way to remove that thick layer of rust was to start working on Helicopter CFI.  Some might call the decision itself a demonstration of questionable judgment. And, from time to time, I’m not all that sure I could argue with them.


That aside, what do you suppose is the thing upon which the most rust accumulates?  As an exercise aimed at understanding the rust removal process, I got to thinking about that before diving in.  Since skill (learning), among other things is a function of exercise (how often you’ve done something), and recency (how long it’s been since you’ve done it), I figured the things that helicopter flight won’t let you practice solo might be high on the list.


I was partly right.  I figured that autorotation, which is the helicopter equivalent of the airplane’s power off glide (if you were to perform it in a grand piano or a safe) would be at the top of the list, and I was partially right. I was right in the sense that the autorotation is the culmination of so many of the foundational skills of helicopter flight, and to my knowledge, no flight school will let pilots practice autorotations without an instructor aboard.  There is a long and gruesome list of ways an autorotation can go wrong. What I forgot (and it’s kind of foolish, since I gave it all away in the previous sentence) is that if the fundamental skills are rusty, the autorotation procedure is going to be RUSTY.


My instructor, perhaps having some experience with rusty helicopter pilots, was wise enough not even to suggest autorotations on the first rust-removal flight.  His decision was justified as I began the flight with an attempt to hover that was only slightly less ham-fisted than an orangutan.  By the end of the flight, I was just sloppy.  The name Foucault came to mind several times during the attempt to hover.


SEVERAL lessons later, with a vast quantity of rust on the floor of the helicopter, we did an entire lesson of full down autorotations (in which the autorotation is performed all the way to a landing – non-trivial, to say the least), which I had never done before.  Believe it or not, it’s not required at either the Private Pilot or Commercial Pilot level.  It IS required for CFI-H.


Going into this exercise, I had the impression that a full-down autorotation was procedurally like combining a normal autorotation to a hover with a hover power-failure induced autorotation.  Not so.  In a hover auto, the helicopter is mostly level, stationary, and stable, from which the power is cut (relatively slowly if you’re wise, quickly if not), and the collective is lifted at a rate that allows a (mostly) smooth touchdown. In the full-down hover auto, the helicopter never reaches the stationary stage, the pilot simply takes it straight from whatever configuration falls out of the autorotation, pitches to level, and waits FAR longer than anyone would feel comfortable, then lifts the collective to put the helo on the centerline and on target.


So, what does this have to do with West Valley and our planes?  First of all, there are parallels as often happen in aviation.  In airplanes, our maneuvers are built on more fundamental skills, techniques, and knowledge, and rust can accumulate on any (or all) of those things.  There’s a reason, for example, that there is a “memory items” test at every recurrent training session that I’ve been to over the last, well let’s say 20 as a number, of years.  Another point is that rust starts accumulating as soon as you stop doing something – you don’t have to wait four years as I did.  That minutely reduced shine on your flying skills that comes after not flying a particular type of plane, a particular maneuver, or even at a particular airport is not a patina, it’s rust.


You can get your rust removed by trying something new that uses the same skills, by practicing the things that it’s been a while since you’ve used them, or by a formal recurrent training program.


My favorite is by doing something new.


There is still a long way to go to get to the CFI-H level, but I’m getting the basics back and building up.


And remember, sometimes rust is useful.  If it weren’t for rust, we wouldn’t have thermite.