## Saturday, October 16, 2010

### Simplifying the equation

Here's the equation that's been bothering me:

X + Y = ???,

where X = Will This Airplane Fly and Y = Can I Fly This Airplane?

Granted, it's a year away at least, but it will have to happen eventually. There will inevitably come a day when I have to fly this thing, and it's apparently never to early to start worrying about it. I wouldn't call it butterflies in the stomach at this distant point, but pupae in the belly wouldn't be too far off the mark.

I simplified the equation today. There will still be worries over the fundamental airworthiness of the completed airplane, but at least I will know for a fact that I can fly it. Today I flew a little more than an hour in the left seat of an RV-12 and made a total of three takeoffs and landings. As a bonus, I also made a fourth landing approach and a go-around. For practice, like. Or so I would have you believe.

In what has to me one of the most masterfully created win-win deals of the young century, I offered to assist a sort-of local RV-12 owner with an introduction to the operation of his Garmin 496 GPS in exchange for a little more time riding around and getting familiar with the flying qualities of the -12. He flew up from Lancaster to pick me up at Bolton and while we were chatting on the ramp in front of the tower, he shifted over to the right side and offered me the Captain's position. Yowza!

Before we started the engine, he gave me a quick tour of the Dynon D-180 so I'd know where to look for interesting tidbits of trivia such as our altitude above the ground and our velocity through the cool fall air. Good stuff to know, those things. The increased level of complexity and sophistication over the more pedestrian mechanical equipment in my RV-6 was in stark contrast to the amazing simplicity of engine management. Time to start the engine? Fine, show me the mixture knob. What do you mean, "there isn't one?" How can that be? Okay, fine. Turn the key? Piece of cake. Whoa! I was expecting to click through left mag, right mag, both mags, and then into 'start'. The last thing I expected was to turn the key straight into 'start'. And wow, it sure does start easy, doesn't it?

Taxiing was a little odd too. Rather than the steerable tailwheel I'm used to, there's just a castering wheel out front. Pressing the rudder pedals has no effect whatsoever on steering. No problem, though. I adjusted right quickly to getting turns started with a little jab at the brakes and stopped with a little jab at the other brake. At the end of the runway, I received a briefing on how to perform the takeoff with the least amount of stress on the nose wheel. The idea was to hold the stick back as I fed power in, and not be surprised when the nose lifted almost right away. Once it did, I was to lessen the nose-up stick and let the nose kind of find its own level. The plane would fly away on its own when it was ready. It sounded a little complicated, but in the event it was quite simple. It was a good thing that I had been forewarned that it would feel like I was going to bounce the tail on the runway with the extreme feeling nose up attitude or I would have panicked and plopped the wheel right back down onto the runway.

I fed the throttle in slowly, but even still it was only a matter of a few hundred feet before we were climbing away from the runway. I have no numbers regarding climb performance to share, unfortunately. I sure that data was available on the display somewhere, but as with the rest of the performance data I found it much more difficult to deduce values from a simply glance like I can with my old clock face gauges. I can tell you this: it was slower than in the RV-6. I knew that would be the case going in, though. It was not a surprise.

I was ready for the light aileron forces, having experienced them in my previous ride, but this time around I realized that the -12 is actually lighter in aileron than the -6. It's actually what I would describe as nimble. As we were climbing away from Bolton, I spent a few minutes explaining how to enter a destination into the GPS. With MadCo firmly locked in, I also took the liberty of reconfiguring the GPS screen to what I consider to be a more useful page setup. I like to split the screen between the moving map and the HSI direction indicator. I think it's a more natural way to look at it for old school pilots.

As we approached MadCo, I became increasingly aware of one thing about the RV-12 that I don't like. More specifically, it's something about the Rotax engine. For some reason that I'm sure would make perfect sense to somebody like a trial lawyer, there is a very strong spring on the throttle that is perpetually trying to pull the throttle knob to the full throttle position. That's all well and good for those times when you want to blast around at full bore, but for the rest of the time it's a right bugger. You see, to keep the throttle from working its way forward, you have to lock the friction control on the throttle down as tight as it will go. That makes power changes somewhat of a struggle. Not knowing any better, I loosened the friction and pulled back the throttle for our descent into the landing pattern. Imagine my surprise when I noticed a couple of minutes later that we not only weren't descending, but weren't slowing down either. The throttle had returned to the higher power position of its own volition. I was to be mildly irked by this behavior for the rest of the flight.

We entered a left downwind to runway 27 and were confronted by the challenge of my first landing with a wind that was blowing directly from.... the west. Right down the runway. What could be easier! As I dropped the flaps (accomplished quite quickly in the -12 by virtue of a flap lever rather than the glacially slow electric flaps of my -6) I hardly noticed any nose down movement at all. Lowering the flaps in the -6 has a far more pronounced influence on the trim. In subsequent landings I would notice that there is a pitch trim change required when lowering the flaps in the -12, but it's minimal. What's far more noticeable is how much heavier the ailerons get when the flaps are down. I don't know if that's by design or just a lucky fluke, but it adds a nice feeling of stability in the landing pattern.

I came down final at 65 - 70 knots and entered the flare at 65 knots. I deliberately flew a much shallower glide path than I do in the -6, correctly thinking that the -12 probably wouldn't be able to lose altitude as quick and easily as I can in the -6. I found out later that while it doesn't come down quite as rapidly as the -6, it is still pretty capable of coming down when you need it to. As I flared over the runway, I was pleasantly surprised at how much more feel I had than in the -6. With the -12, I could move the stick quite a bit in pitch with minimal yet predictable changes in the landing attitude of the plane. The -6 is, in comparison, very twitchy in the flare. The least little movement has a tremendous affect on the attitude of the plane, and in consequence can cause all kinds of embarrassing bounces and oscillations. At the end of the day, it came down to this: I greased all three of my landings, at least on the Richter scale that I use for grading landings in the -6.

I mentioned a go-around earlier. After MadCo we headed over to Circleville to try a crosswind landing. Without the wind coming right down the runway to abate our ground speed, I ended up high and fast on short final. I punched in a bootful of right rudder and held the wings level with left aileron and we dropped down like a brick, but I still felt that an awful lot of runway was sliding behind us and the plane wasn't perceptibly slowing. Discretion being the better part of valor (and me not wanting to abuse the generosity of my host), I poured on the coal and took us around for another try. Better attuned to the weather conditions and the performance of the plane, I squeaked on the second attempt. Two for two, if you don't count the go-around. Call that one a mulligan.

By the time we got back to Bolton, I was completely comfortable in the airplane. While it will take time to adjust to a 110 knot cruise speed, I will quickly learn to love the 5 gallon per hour fuel flow. The benign flight qualities will please, but the bouncing around that comes with the light wing loading will take some adjustment. I was again surprised at how quiet and smooth the engine is and how comfortable the seats are. And the improvement over the already exemplary visibility of the RV-6 is amazing.

All in all, I can say in all honesty that the RV grin that I wore for the rest of the afternoon was well earned by that wonderful little airplane.

#### 1 comment:

1. I found the equation in your page for Sat Oct 16, 2010

X + Y = ??? (plus the following line).

Love it, will use it with your permission and your name attached.

Gail of Rick's bro-in-law fame