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.

Get Control

You need to be able to see the screen you want, when you want it. There are a number of keyboard commands to control it - but in fact you can get by with just three (which ideally you assign to buttons on your joystick).

These are ‘Handheld next screen’ (default Key M), and ‘Handheld Zoom In’ (default Key PgUp) and ‘Handheld Zoom out’ (default Key PgDn).

By using the ‘Handheld next screen' button on your joystick you can always cycle to the one you want pretty quickly, without fumbling on your keyboard.

So what are the screens?

There are 5 different screens that you can access any time that are helpful in different situations.

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 4 - Thermal view

Yes it’s out of sequence but it’s an easy one to get out of the way.

Selecting this screen will show a ‘breadcrumb trail’ along your glider’s track. It will show descent (in blue) and climb (in red), the intensity of the colour depending on strength of either.

When thermalling you are trying to achieve a consistent dark red circle - this is consistent with a ‘constant excited vario’ sound. If you are not centred accurately the view of this circle will show you where the best lift is, helping you to centre. And if it’s half red and half blue you really need to tighten up or move the circle, or both. All this will be obvious to experienced pilots/soaring app users, but if you are just learning soaring this is really handy to know. Thermalling needs practice, practice, practice.

Your average climb rate is shown as a number on this page. The default setting is an average over 20s, but you can adjust this time in 'Options'.

This screen also is really handy if you are in ridge lift in a mountainous area, beating back and forth to climb. Displaying it will let you easily see where the best lift areas are. But now you need to look out for terrain as well as other traffic, don’t get stuck looking inside!

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 2 - Navigation

This screen is useful for telling you your longitudinal progress on the current leg, i.e. to the next waypoint.

There’s a semi circle at the top, with a black dot. This dot shows you the direction of the waypoint - relative to your current heading. If it’s right of centre you need to to turn right until it’s at the top - then you are pointing directly at it.

Underneath you have speed information.

Let’s consider wind first. If you are flying straight at the waypoint at 100kts indicated, into a headwind if 40kts, the VMG will be 60kts.

If flying in that direction at the same airspeed with a 40kt tailwind your VMG is 140kts.

It’s simple enough when you get this part.

The other part of VMG is angular. If you are pointing straight at the waypoint then your VMG is your groundspeed. If however you are flying at 90 degrees to the correct heading then your VMG will be zero, even if your speed is 100kts. Naturally enough, as you turn towards the waypoint your VMG increases.

The PDA is constantly updating for both wind and ‘angle’ of flight.

Now that the PDA knows what your VMG is, it calculates how long it will take to reach the next waypoint given your current speed. This is the time shown next to TTG - the ‘time to go’. Finally it adds TTG to the current time and calculates an ETA - your predicted arrival time.

Bear in mind that when you manoeuvre, your speed and heading will change. The PDA constantly recalculates all these numbers.

The time estimates will of course be significantly delayed if you stop to climb - which you may well need to.

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.

The red dot

The red dot on this screen does two things. It provides lateral guidance towards the next waypoint - as per the black dot above.

It also gives you a graphical view of DDH, i.e. you can quickly see if you are going to arrive high or low. If the red dot is above the cross, you don't have enough height to reach the selected waypoint (DDH is negative).

In the final glide to your task’s finish, this screen is really useful. If you have excess height you can push up the speed and burn some of it usefully, knowing you still have enough height to finish.

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.

MacCready Magic

So, to complete the story, we need to go back to BF1, the MacCready setting.

We know that gliders can glide a long way - according to their 'glide ratio'. Published figures are for ‘best glide’, which is at a relatively low speed.

What MacCready does is look at efficiency in your flight based on the quality of lift available.

In super simple terms it says that if the lift is good, you should fly faster, and if it’s bad, slower.

Before you launch, look at the sky. Are the thermals going to be good? How good? What average climb might you expect? Let’s say you think it might be 5 kts. You can launch, and go test the thermals before you start the task, and modify your prediction based on what you actually find.

Now you have your best prediction you can go tell your PDA. The MacCready setting ranges from 0.0 to 9.7 kts, or 0.0 to 5.0 m/s depending on your setup. 0.0 is the default setting as we saw earlier.

Adjust the MacCready number using MC + key (default key 'Home') and MC - key (default key 'End'). It moves 0.2 kts (0.1 m/s) at a time, and you hear a click each time. After a lot of clicking you can set your value for today, let’s say it’s 5.0 kts, a pretty good day in the UK.

What happens now is that BF2, your white diamond, is set to a new baseline, and it will demand you fly a lot faster. It will still demand speed changes as before with lift and sink, but these are based on that new baseline.

There’s quite a bit to understanding MacCready fully, but to try summarise it - the penalty of having a higher descent rate due to higher speed is more than offset by the fact you get to your next (strong) climb quicker, and top up energy more quickly again, and so on.

If you do this on a good lift day you will easily beat someone who who leaves MacCready at zero. It’s BF1, enabled by BF2!

As conditions change through the day you may find you need to adjust your MC setting. Typically as lift gets weaker later in the day you may want to reduce it. Remember it’s based on your prediction of the lift you expect to find next.

The best explanation I have found for speeds to fly and why MacCready works is here:

Have a look when you have time.

A slightly different mode

The last thing you may wish to know about the Vario is that you can change its mode.

If you press the 'Right CTRL' key, two things happen.

One - the Vario sound changes from ‘beep beep’ to a constant tone. It actually is BF2 talking to you. The tone is equivalent to the red / blue bars extending from the white diamond. Putting the speed right will silence the tone and put the white diamond back in the middle. I think the designers deliberately made the tones annoying to make you silence them!

This mode is useful when you are in the glide between thermals but you don’t want to be staring at the vario. Your eyes should be outside as much as possible in any case.

Two - the number in the centre of the vario is now changed to be a ‘Netto’ vario. Instead of what you are doing (remember you are in a glider you will always be going down relative to the air), this number now shows you what the air is doing, be it rising (+) or sinking (-). This is very useful to know - i.e. if your planned route near terrain is actually producing the lifting air that you expected.

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