The Condor PDA

So there’s this thing in my glider and I don’t have a clue how to use it..! Don’t worry, help is at hand..

The PDA in Condor is actually a really really useful piece of (virtual) kit. Spending a little bit of time getting to know it will really pay dividends.

This is actually a fabulous opportunity to learn a lot of stuff that is totally useful in real life gliding also.

Let’s have a look.

PDA Screen 1 - Map view

This shows your glider (in white) at the centre of the screen, and a portion of the world around you, depending on your zoom level. The orientation is always North up. Other gliders in an online session show in this view (in blue) if they are in range.

If you have an active task, you will see this also. The track lines between waypoints are shown in blue.

Waypoints are centred at a specific, defined point, but can have different shapes and sizes based on that point. Start and finish gates are typically 180 degree sectors with a 1-3km radius. Intermediate waypoints can be 90, 180, 270 or 360 degree sectors of variable radius, it all depends on what the task designer has specified. The current ‘To’ waypoint shows up in Red; others are in green. To ‘turn’ a waypoint you just need to fly into the sector - which is easy to see in the map view. Zooming in as you approach the sector can help.

Some waypoints have a minimum or maximum altitude, in which case you can only successfully pass the waypoint if you are above or below that. If specified, these heights will be shown on the map in an abbreviated form.

Some map views also enable you to see the terrain relief - this is extremely useful for route planning in mountainous areas where ridge lift is present.

Usually waypoints have large sectors. But the task designer may define a specific ‘Window’ that you must fly though. Windows have a very specific position, centre elevation, width and height.

Both the reference position of the waypoint and any ‘Window’ will become visible if you use ‘task helpers’ (default key J). Windows can be very difficult to fly through if you don’t use this. It’s another key you may want to map to a joystick button.

This map screen is useful to have up most of the time.

PDA Screen 4a - Wind

This screen displays a wind arrow i.e. where the wind is coming from and it’s strength. Check this periodically because it can change. If you are in a valley pay a lot of attention to this. Not only can the valley influence the wind, but the lifty/sinky side of the valley may change. Use this wind info and the map screen (your relative heading and proximity to terrain) to stay in the lift.

PDA Screen 3 - Vertical information

This is the real hidden nugget of gold in the PDA, you just need to know what it’s showing you.

We’ll come back to the red dot at the top.

We need to talk about DH. What’s that?

Well it’s actually pretty simple - it’s how high you are now, compared with the elevation of the waypoint you are flying to.

So if you are at 2000’ (QNH) and your ‘To’ waypoint is NHL (at 900’) you are 1100’ feet above it. That’s your height information now. Your DH.

The tricky bit is DDH - what’s that?

Well, we already learned the PDA can do speed predictions. If you take that concept and flip it on it’s side - it will give you vertical predictions too.

The PDA knows the polar curve of your glider. It therefore knows that on average, if you fly a given speed, for a given distance you will descend by 'X’.

The PDA knows the wind - so it can shift the polar curve as required for head or tailwind components.

So, if you fly that given speed, and conditions around you don’t change, the PDA can take 'X’ off your height now (the DH), and calculate the DDH - your predicted arrival height over that waypoint.

If the number is negative you will either need to climb, or dig a tunnel to arrive underground. Climbing is usually easier.

And now for the final really clever bit.

Remember the PDA 'zoom in' and 'zoom out' buttons you conveniently put on your joystick? Well you can use them to zoom in and out the map view as you fly, but also you can use them to select a different waypoint on this vertical screen.

Pressing ‘zoom in’ once will advance one waypoint and a big ‘+1’ will appear at the top.

Now the DH and DDH will give you data about that next waypoint, and you can see if you will need to climb to reach it.

Keep pressing ‘zoom in’ and you will display the last waypoint in the task, i.e. the finish.

Now you can see if you are high enough to finish the task... Kinda useful!

Even before you start, you can use this function to understand exactly how much climbing you will need to do to get all the way round the task at your selected speed.

Note that if the task has a minimum specified height at a waypoint (usually the finish), the PDA will provide information corrected for this requirement.

A few words about speed

What’s my selected speed and how do I fly it?

Well, it varies! But again help us at hand..

On all but the most basic gliders in Condor, the Vertical speed indicator - VSI - more commonly called the variometer or just vario, is a very clever instrument. There’s a conventional mechanical (nearly instantaneous) vario, and, in the centre of the screen, it displays your average climb / sink rate (exactly the same number as that you saw in PDA screen 4).

Below that is a number, which is probably stuck on “0.0”. This is the MacCready setting. And it’s your new best friend. You just need to get to know him. We’ll come back to BF1.

In fact it’s gonna get crowded here because you have to make room for yet another best friend. On the right side of the instrument is a white diamond.

At least it’s white some of the time. And you want it to stay that way. White means that according the PDA, the VSI and your MacCready setting, you are flying the correct speed. Correct meaning ‘most efficient’.

If we refer to polar curve theory this is the speed at the tangent to the curve. In still air this is the tangent to the origin.

When you fly into sink, the polar curve needs to be shifted a bit, this gives you a higher required speed to remain ‘efficient’.

The diamond, your new BF2, now automatically asks you to increase your speed - by a blue marker extending downwards from the centre. Pitch forward to increase your speed until this blue goes away, and you just have the white diamond again. Now you are flying the correct speed to be most efficient at this given moment.

Suddenly the sink stops and you fly into lift. Polar theory says we need to slow down to remain efficient. The PDA recalculates the required speed and the diamond this time extends upwards - in red. React in the opposite sense - pitch up to decrease speed, until you see only the white diamond again. Once again you are now flying the most efficient speed.

It’s a constant process. Air is always changing; both headwind/tailwind and lift/sink. So it follows that you need to constantly adjust your speed to keep that diamond white.

If you do, you will be efficient, and competitive!

In practice what this means is that if you fly next to someone in exactly the same glider and at the same MacCready setting, if they are indisciplined with their speed control and you follow the diamond and are efficient, you will arrive at the next waypoint with more energy (i.e. higher) then them. Which is - most likely - what you want.

Have a look when you have time.