Silicon Visualization

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One of the

This material originally appeared in Pipers and Cessna Owners Magazines, and is reproduced here with the permission of Aircraft Owners Group.

Airmanship

I'm planning a flight from my home base in Modesto, Calif., to Seattle, Wash., -- and back -- on business. The appointment I need to keep is on a Tuesday -- giving me all day Monday to get there -- in early summer.

The tools I've used to plan the trip are mostly traditional: the necessary IFR enroute chart and sectionals, route planning and forecasts from DUATS, and I'm using the Weather Channel to look at trends. While the weather at this time of year is relatively dry, it's hardly cloud-free, so an IFR route looks like a good idea -- and I used the route planner in DUATS as a starting point for this. It came up with a route over Sacramento, Calif., Medford, Oreg., Eugene, Oreg., and finally Seattle-Tacoma International airport into my destination: Boeing Field.

This route has 10,000 foot Minimum Enroute Altitudes (MEAs) on two segments. My airplane can go higher, but not by all that much. An alternative route along the coast would let me stay lower most of the way but still requires 8000 feet and would add an extra hour's flying time. Looking at both routes on the sectional charts gives a better feel for the terrain -- but at this point, I can also apply some silicon to the problem: Using Microsoft's Flight Simulator 2002 (FS2002), I can actually see what both routes look like, from the pilot's point of view.

Flight Simulator Flight Planning

Flight Planner Here's how to do it (if you don't have a PC flight sim, skip down below to Now Watch the World Go By!). The specific menu items and buttons I'm about to mention are specific to FS2002, but if you have an earlier version or a competing PC flight simulator, you should be able to do something similar. Start FS2002, and you'll see the Create a Flight dialog. Start by selecting an airplane that's generally similar in performance to what you'll be flying. I want one with a full panel, so I'm using FS2002's Cessna 172SP Skyhawk -- selecting the variant with an IFR panel.

Now press the Flight Planner button. Enter the airport you plan to depart from and your intended destination. You have basically the same choices for routes that you'd have using DUATS or any other flight-planning software (I'm using the Low-Altitude Airways option), and press the Find Route button. The route it generates is identical to what DUATS generated for me earlier. Press OK.

Now add weather: Click the Change tab below the Current Weather box on the left side of the display. This will take you to the Weather dialog. If you have an Internet connection, simply click the Real World Weather button, and FS2002 will download a summary report of current weather. Once it's complete, you'll have (mostly) realistic clouds, visibility, and precipitation. If you don't have an Internet connection, you can still approximate the weather conditions you'll face manually using the controls on this display. Press OK when you're finished.

Now click the Fly Now tab at the bottom of the Create a Flight display. This will take you to the cockpit of your selected airplane at your departure airport. The engine(s) will already be started, and you'll be placed at the departure end of the active runway.

Preflight

C172 IFR Panel

Inspect the panel carefully and you should find a row of four icons that look like a check-mark, headphones, a compass rose and a satellite dish (on the IFR Skyhawk panel, they're located below the ADF readout, just to the left of the fuel selector). Press the icon that looks like a satellite dish and a GPS moving-map will pop up. I like to resize it to fit over the NAV-COMs. Note the bearing to the first waypoint and set that in the #1 CDI (the indicator that's normally used by NAV-1) using the OBS knob (move the mouse pointer over the knob and click to "turn" the knob).

Now look for a toggle switch labled "NAV-GPS" (on the IFR Skyhawk, it's just to the left of the Outside Air Temperature indicator, below the magnetic compass). Click on this to move it to the GPS position. This will allow the autopilot to guide off the GPS receiver and automatically track the course we laid in while planning the flight.

Which just leaves us to set the autopilot -- on the IFR Skyhawk, it's at the bottom of the radio stack (you may have to click the satellite dish icon to dismiss the GPS moving-map in order to see it). Set the altitude to your planned cruise altitude (for me, 10,000'). FS2002 will default to a vertical speed of 700 feet per minute, which is fine. Finally, set the heading bug on the DG to line up with the runway heading.

Virtual Flight

Ready for Departure We're now ready to depart. To make it easier to stay lined up with the runway, press the "W" key on your keyboard -- this will give you a wide view (equivalent to looking up over the glareshield). Advance your throttle to maximum, and press the "." (period) key to release the parking brake. You'll see the scenery begin to move past. Once the airspeed's into the green arc, smoothly rotate using your joystick or yoke (it can be done with the keyboard, but I really don't recommend it).

Once you're established in climb, press the "W" key twice more to return to the full instrument panel view. Click the AP button on the autopilot to engage it, then the HDG button, and finally the ALT button. You can now let go of your joystick or yoke (it may take a few seconds to settle). When you're at a reasonable altitude, press the NAV button on the autopilot -- and the airplane will turn as necessary to intercept your flight-planned course.

Now Watch the World Go By!

At this point, you can just sit back and watch the outside view (press "W" again); but it's also possible to take advantage of the fact that we're in a simulator rather than the real airplane: Find the digital clock on the panel (located below the DG on the IFR Skyhawk). The top number on it will simply show 1.0. Move the mouse pointer over that number and just to the right until the pointer shows a plus sign "+" superimposed. Then click. The number will change to a 2 -- indicating a time compression of 2:1. Every second in the simulator will be equivalent to 2 seconds real time. Additional clicks will speed this up to a maximum (with the autopilot running) of 16:1, which cuts a 6 hour cross-country down to size nicely!

I find that turning the time compression back down to something like 4:1 or less is helpful when the autopilot levels off at the cruise altitude and when it makes turns at waypoints, but once settled back on a straight-and-level course, speed it back up.

As the virtual airplane moves along the simulated route, the outside view shows both the terrain and the weather. FS2002 gets its weather information from the same automated reporting stations as DUATS, which can produce abrupt changes -- you may find yourself flying through completely clear skies and suddenly pass a boundary and find a lot of clouds. Of course, in the real world the change would likely be gradual -- but it gives a pretty good idea of what the weather will look like, in general.

Medford Arrival

I've done this every couple of days for the last week -- focusing on times when the weather wasn't clear. My trip to Seattle looks flyable; I can expect to be over the tops at 10,000 feet (or at worst, with another 2000 foot climb). I may have an IFR let-down to get into Seattle (or my fuel stop at Medford), but most likely the cloud bases will be high, with pretty good conditions underneath -- well above IFR minimums.

FS2002's presentation of weather isn't by any means perfect -- among other things, it consistently overstates surface visibility, and while I've compared the cloud tops in FS2002 with those in the DUATS area forecast and PIREPs, I know that it's only an approximation, at best. As a double-check, I've talked to two pilots with experience on this route -- and they've described conditions very similar to those I've visualized with FS2002.

Could I have visualized this route without FS2002? Certainly -- pilots have been doing this kind of thing since long before desktop PCs were invented. I've done it myself on other trips -- but given that the tool is available, why not use it? As I write, I've spent something like five hours simulating both the primary and alternate routes, under a variety of conditions. When I get in the airplane tommorow and fly it for real, I'll have a much better idea of what to expect. I'm sure it won't be exactly the same -- and that's OK. If everything went according to plan, flying would be an awfully boring business!