Tuesday, December 28, 2010

I'm not lost...

What happens when a non-pilot tries their hand at navigating an aircraft?

Those of you who have been following along over the last couple of years will have noticed me mentioning my good friend Jim, who is a splendid chap and is very generous with the right seat in his aeroplane, a Vans RV-7A.

Aside from a couple of trial lessons many years ago, I have no formal flight training. However, I have been lucky enough to fly often with Jim over the last two years, and each time I fly, I learn something new. Jim has given me control of his aircraft around the patch, where I have practiced steep turns. I can hold a course and maintain a reasonable altitude. We have tried some slow flight in which I handled the aircraft with mushy-feeling controls. Jim has shown me a practise forced landing, and we have flown some of the SARL air race courses around the Taylor area. We even took a long cross country flight over to Marfa in West Texas, about 350mn each way. Naturally, Jim remains Pilot in Command, but it's great to be able to have a go at flying.

Much of the time I'll be photographing or videoing the proceedings, but there's only so many pictures you can take of the view, and I need to make the most of these flying opportunities. And I wanted to know if I could find my way about without the GPS that we normally use. Jim often asks me, "So where are we going today?" and I wave into some random direction and off we go, which is all well and good for local flying, but doesn't really stretch our navigation skills.

So when Jim invited me to fly this time, I figured I'd better have an answer for him for the question of where to go. I sat down over breakfast with the San Antonio sectional chart and plotted a triangular course. From Taylor, perhaps we could fly to Skylark, then to Cameron and back to Taylor. I drove off to the airfield and met with Jim, who looked at it and figured Skylark was a bit close to the restricted airspace around the military base Fort Hood for his liking, so why didn't we go to Salado, then fly up to Marlin, down to Cameron and back to Taylor?

You can follow our journey with the letters on the chart below…

We preflighted the aircraft, topped off the fuel tanks and were set to go. A bright blue sky punctuated with mid-to-high level clouds awaited us. It was a cold morning by Texas standards, so the RV leapt into the air in short order as we took off to the south. Jim steered us to the west and out of the circuit, and asked me where we were headed. I gave him a heading of 350 degrees and away we went. Shortly afterwards, Jim asked if I wanted to fly as well as navigate? Hell yeah! (A) Jim was on top of things, adjusting the throttle as needed, keeping a watch for potential landing spots etc, but our direction and altitude were mine to control.

Now, I should mention here that although Jim has 40 years of flying behind him, he is not a flight instructor (unless he's been hiding something from me) and I have never done navigation before in my life. I know the compass bearings and have an idea of the theory of flying a bearing and time to get somewhere, but I hadn't prepared the route in that detail. So there I am, chart in one hand and stick in the other, guiding us as best as I can towards Salado. I am studiously ignoring the GPS in front of my nose; too busy looking out of the window for landmarks.

I can see a main road with the railroad in parallel to our track on the chart, and there they are to my right on the ground. They bend away to the right, but there are some power lines that lead me in the general direction of Salado. There is a river, and there are the second set of power lines, just as expected. Here is Salado on our nose, and Jim reminds me I'd better turn right before we fly over the local airfield that is used as a parachute drop zone. I kept my eyes very peeled for parachutists but saw no activity. One steady turn to 060 degrees later, we were heading for Marlin. (B)

I am watching for the main road to cross our path; there it is. I can see the large town of Temple off to our left. Here's the second main road, followed by two rows of power lines. They are getting hard to distinguish; the haze is increasing as the day warms up. It blankets the horizon in white nothingness. We keep going. I am trying hard to maintain altitude at 3,000ft but I'm all up and down. I can usually do this better than I am doing but then I don't usually have my head in a chart. It is getting bumpy and the aircraft is kicking around a bit. Now there are very few landmarks; the land is wide and open and beige and brown, the colours of Texas in winter.

Holding my heading, I am looking for the town of Lott. Eventually it appears off our left wing. We are a bit further to the southeast than we should have been, but at least I know where we are. That was a nice thought while it lasted! (C)

A slight turn to the left, and then to the right. (D) I'm really not sure why I didn't look at the compass, but I turned way too much to the right. I'm flying along, looking for the town of Marlin and not seeing it. But surely by now, we should be on top of it? Then my eye happened to catch sight of that darn GPS and it showed the aircraft pointed in a decidedly east direction, when we should have been pointing much more North. I said to Jim, "Erm, we appear to be heading East!" (E)

Lesson 1: Look at the compass! Even if it suffers from compass lag, it helps to actually look at the thing in the first place!

Lesson 2: If the roads and rivers are where they are meant to be, but their angles intersecting your path don't look like they do on the chart, then you're going the wrong way.

I should also mention that this particular RV-7A is a lightweight, slippery example of the breed and we are doing about 200 knots. This means mistakes happen pretty quickly at around three miles per minute. So we continue further East while Jim and I discuss the situation. We agree that our position is a bit north of Bremond. I suggest that Hearne is nice this time of year and perhaps we should head for there? I begin a turn to the south (F). Jim then suggests we should head back towards Taylor, so I swing the aircraft around to a southwest heading. (G)

We maintain a steady course, and I am really keeping an eye on my altitude now as I've annoyed myself by not doing so well enough thus far. We have descended to 2,500ft and I challenge myself to remain within 100 feet of this, which I achieve for most of the way home, even though the air remains bumpy. On turning towards the sun, the haze has whitewashed the horizon even more now, and there are not many obvious features with which to cross check my position, but I keep us flying straight and we pass the town of Cameron off to the right; I can see the airfield on the edge of town. (H)

Now here is where it gets embarrassing. Jim pointed out the lake ahead, saying, "There's the power plant over towards Taylor". For whatever reason, I got it into my head that the lake was Granger Lake. No matter that I have read plenty about get-you-home-itis, and about becoming convinced that things in front of you are what you think they are, not what they actually are. No matter that I didn't think we had flown far enough to be that close to Taylor, nor had we crossed the roads and river marked on the chart between Cameron and Taylor. No matter that there wasn't a power plant on the edge of Granger Lake the last time I flew over it a couple of months ago, and they don't build them that fast. There was a lake, whose shape I was twisting around in my head, trying to match it to the chart.

At some point around the letter (I), I must have mentioned this, at which time Jim put me out of my misery and suggested that I follow the large, handy road back to Taylor…

Lesson 3: Things on the ground are what they are, not what you want them to be!

We made a right turn before reaching the town (J) and headed over the real, actual Granger Lake (K), which is a whole lot bigger than the smaller one we'd just seen, and completely devoid of power plants. We made a wide approach to Taylor to avoid traffic (L). I started the descent and Jim took over control, landing us back down onto Taylor's tarmac.

I learnt one heck of a lot on this flight. Even though Jim was doing the throttle, lookout, radios and being pilot in command, I am pretty proud of the fact that I flew an airplane around a course, and while it was far from perfect navigation, I was able to pick up from my mistakes for the most part. Maybe one day I can learn this in a formal training situation and put it together properly. Those kinks in the route? I wasn't lost…. just temporarily uncertain of my position ;-)