Thursday, July 23, 2015

The Flight Review

Every couple of years (give or take a few days), I have to take a ride with a certified flight instructor (CFI) in what id called a Biennial Flight Review (BFR), the purpose of which is somewhat murky to me. It would make sense to say to a lapsed pilot that you have to take some level of refresher training, but for someone that has been flying regularly and has managed to stay alive, well, it seems like more of a formality, especially when you consider that it isn't a check ride - there is no pass or fail.

That said, a CFI can refuse to sign off the BFR as complete if you're completely inept, but nothing stops a person truly dedicated to flying himself into an early grave from simply finding a more pliable CFI.

Loath to waste the dollars paid to the CFI to just bore holes in the sky for an hour, I usually pick something to practice and/or learn. This time around I thought it would be a good opportunity to see if the Dynon SkyView and autopilot were capable (as opposed to 'legal') of flying a GPS instrument approach. I chose MadCo, primarily because its very close to home base. The forecast winds were showing runway 27 as the preferred runway choice, so I downloaded the RNAV (GPS) RWY 27 approach plate from the internet. I actually have these approach plates built into the SkyView, but I wanted a chance to get a good look at it before flying it. It has been a very long time since I was instrument current; so long, in fact, that I have never seen or flown a RNAV (GPS) approach.

Here is the approach plate:

The unmolested plate doesn't have the bright red line on it - I drew that on so you could see the course we would be flying.  I'm lazy, so the intersections aren't rounded as they were when the route was depicted on the SkyView.

Note that the SkyView is not approved for this type of usage. That said, while I can't see myself ever screwing up badly enough to ever need to do this for real, it doesn't hurt to be prepared. There are plenty of other stupid things that I've done despite believing that I would never be stupid enough to do them, so.... better safe than sorry, and whether I would ever fly an IFR approach in my plane isn't really the point - just spending time flying with the Foggles is worth the effort.  

Even if I never stray into a big cloud, I may still find myself in a situation where I need to be able to control the plane by reference to the instruments. Have you ever driven into a setting sun on a hazy day?  Yeah, that.

Because the SkyView isn't approved for instrument approaches, it doesn't have the niceties that make the routine use of approaches easy. For example, I could simply load the approach, which would automatically load the waypoints into a flight plan. Instead, I had to manually create a flight plan for the UHAGY → AKPUC → FOFWI → JADMU progression. Even that was more difficult than usual because Dynon seemingly suppresses the automatic completion of a waypoint entry for these types of fixes - I had to enter all five letters. That was easy while sitting on the ground, but would have been much trickier in the air in even moderately bumpy conditions.

I decided to fly the first attempt more or less by hand, and see how well the autopilot could do it after I had my chance at it. I say 'more or less' by hand because I did use the flight director.

"That what??!?"

The flight director is related to the autopilot system. It displays a guide on the artificial horizon, which shows the attitude of the airplane, but does nothing to control the plane. The guide represents a reference of an airplane attitude that will follow the parameters set for the autopilot. The pilot can manually fly the plane directly where the flight director indicates, and by doing so the plane will follow the parameters set for the autopilot.

It looks something like this:

The two purple trapezoidal bars (positioned horizontally in the picture) are the flight director indicators. The yellow bars nestled up underneath them are the indicators for the current bank and pitch angles being flown. When the purple and yellow bars are tightly nestled like that, the plane is oriented exactly the way the autopilot would have done it.

What this would look like to be as I was hand-flying the approach would be, assuming I need to make a left turn to stay on course (or intercept a new course) would be the purple bars rolling into a bank to the left while the yellow bars stayed behind. I would move the control stick to the left which would roll the actual airplane into a left turn. This would cause the yellow bars to roll to the left also, with their angle being commensurate with the bank angle of the airplane. If I were to 'fly' the yellow bars such that they stayed matched up with the purple bars, the airplane would follow the precise path determined by the flight plan.

Letting the autopilot do it would be the easiest way, but if for some reason I wanted to hand fly (too bumpy, or whatever), using the flight director would be the 2nd best choice.

It went well, but the RV-12 is a light plane and the weather wasn't super smooth, so there ended up being a lot more lag between the purple bars telling me what to do and me doing it.

The autopilot logic did a very good job of giving me plenty of notice for upcoming turns. The very tight hairpin turn to the right at UHAGY was the one that I thought might be a bit of a challenge, but in the event it was no steeper or any more difficult than a normal turn, albeit a bit steeper than a standard rate turn. I looked into making a setting in the autopilot configuration screen, but there is no such option. This seems odd as it would be easy for the Dynon to make the required calculations and adjustments to make standard rate turns.

After a not-so-great landing, we went around again and let the autopilot fly the entire approach. I took the Foggles off for that - I wanted to keep an eye on what it was doing. It did a great job. All I had to do was manage the step-downs in altitude, and even that was simply a matter of turning a knob. The landing was no better than the first one, though.

We went on to do a couple of pro forma slow flight maneuvers and such, then it was back to base. I let the CFI make a couple of landings, thinking that his would surely be worse than mine, but it wasn't to be.

Oh well.

It was worth doing, I suppose. I learned a little bit more about the capabilities of the autopilot and the practice time with the Foggles was definitely worth doing, so I have that going for me for the next two years plus a few days.

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