REP: User Interface Preview

In my last post I’ve promised some screenshots of the user interface that REP provides to you to manage your aircraft.
With the Reality Expansion Pack you can manage your aircraft’s systems in the “Hangar” window.
The screenshots that I’ve attached are those of the working UI that we are already using. Keep in mind that there are still a lot of things that we want to improve (and more tabs that we will add, such the one related to the Oxygen System).
These screenshot are related to the Hangar window only. More pictures of the other windows will come in the next weeks.

So, here the images.

Engine user interface

In the “Engine” tab you can check the status of each cylinder and fix them id necessary. You can also check your oil and change it when necessary. At the bottom, you can check the starter status.
The engine management interface

Electrical/Avionics user interface

In this tab you can check the status of the battery and fix the avionics (which may be broken if it was already turned on when you started or shutted down the engine). Unchecking the little checkbox will disconnect the battery to avoid a self discharge when the plane is not flown for a while.
The electrical system user interface

Landing Gear user interface

Here you can check and fix your landing gear mechanics, the brakes status and the tires damages.
A bad landing may results in a damaged landing gear as much as a prolonged braking may overheat the brakes.
The landing gear user interface

I think that the next week I’ll be able to post something more.
Stay tuned!

PS: Some user complained that the XP user interface is ugly.
I agree with you that the default XP interface isn’t something you would call “beautiful”.
We decided, anyway, to use it mainly for two reasons:

  1. It is consistent: It works using the same flow of the sim interface
  2. It may be replaced easily with some custom graphics: we can easily update our code to replace the default X-Plane style with something else if it’s needed. If you look closely, you will see that we have already replaced the progress bars.
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REP: The electrical system

I’ve been out for a while. In the meantime the work on REP is gone further ahead.
We have been working on the electrical system (which is not really complex on a GA airplane).
The most complex components are the battery and the alternator.
A Cessna 152 battery (lower left corner)Both are rendered quite realistically in X-Plane so we didn’t have to do much work, I must say. Mainly, what we did is model the battery dynamics when the battery itself is switched off.
A battery is, in fact, “alive” even when you are not using it.
For instance, every battery suffers of self-discharge and so does the battery we have on board of our GA piston aircrafts.
A self discharge is a phenomena that takes action when the battery is not used. Also, it is more effective when the battery is connected to a circuit, even if the circuit is turned off.
REP keeps the battery state between sessions: if you discharge the battery and then reload the sim, you will get the same electrical charge you left in it in the previous session minus a little amount dued to the battery self discharge.
The amount of charge lost by self-discharge is relative to the amount of time the battery was left unused, so if you leave the sim for two days you will loose less charge than leaving the sim for two weeks.
If you plan to not use a REP powered plane for a long time (for example, for an entire season) you may want to disconnect the battery in order to keep it safe. You can do this via the “Hangar” menu of the plugin.
If you disconnect the battery it will still loose a little bit of charge but not too much.

That’s it for today!

PS: In the next days I’m planning to release some screenshot of REP’s UI and maybe a video showing part of the damages system. ;-)

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REP development: from devs to sim pilots

I want to explain a little bit how REP is developed and what we plan for the next months.
We are at something like the 50-60% of the REP development and we have written more than 12.000 lines of code.
It’s a lot of time that we started this project and so I think you should know why you have to wait so much for it to be ready.

The REP development

As I said in my other posts, REP is not only a plugin but a set of flight dynamics, sounds and, of course, C++ code.
In the past months we created a robust codebase that, if correctly configured, can simulate almost any mechanical part of any aircraft.
Basing on our personal experience as developers and real life pilots, our efforts were spent to provide a deeply modular code structure made of something like LEGO® bricks. We can now add, remove and modify parts of the system on the fly.
Also, a modular system allows us to easily test every component outside X-Plane, using a bunch of automated tests that ensure that everything is working as expected.
Our plan is to have a first version of the software that can be upgraded fast, adding more bricks in order to provide more features.

No aircraft is like another

There’s no way to get an accurate simulation of every airplane with just one software without a very precise configuration.
Let’s be clear: REP will work with one plane at a time. It means that we will release REP for, let’s say, the Cessna 172, then we will release (after few months) the PA28 and so on.
This means that REP will not automatically work with every airplane that you load in the sim because the sim itself does not provide enough information about the airplane you are using.
For example, if the airplane is powered with a turbocharged engine, wich kind of turbocharger it is? How does its wastegate work? Simply we don’t get this information in the sim so we need to configure the systems for each plane we want to fly with REP.
The need for a very deep system configuration requires a lot of attention to details thus it take a lot of time.

Reassuming:

  • We’re working very hard
  • Releasing the first aircraft will take much time
  • Releasing the other aircrafts will take much less time

    See you soon!

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    REP: Engine temperature management

    While talking to a friend about REP, he asked me about how the engine temperature and cooling would be modelled. I replied that the engine management will track the engine temperatures and simulate their impact on the engine behavior (and failures). This will make the pilot motivated to take care of his engine.
    Eventually, his point was about how the shock cooling is simulated in REP.

    There are two theories about engine cooling. Someone says that the shock cooling actually does not exists. Someone else says that it’s an important factor to keep in mind when it comes down to correct engine management.

    Let’s start with a number: 30.
    30°F/min is more or less the temperature difference at wich, in theory, a cylinder should start cracking. So, if you follow the first theory, you must be very careful when flying because that temperature ratio is not that hard to reach sometimes. But what about the engine shut down?
    When you shut down the engine at the end of each flight, for few seconds you get a much higher ratio than that but no cylinder cracks.
    So which theory is right? You can find a very interesting article about this topic on AVweb.

    In a Cessna 210 the engine temperature is a key factor

    That said, REP will work in between the two theories as I think it better fits my own real flight experience.
    You will mainly have to follow the rule that says to keep the needles in the green arc. So, for example, after starting up your engine, do not boost up your RPM if the Oil Temperature, the Oil Pressure or the CHT are under the green arc.
    With a modern Continental or Lycoming engine, if you fly with this rule in mind you will hardly encounter a problem when flying.
    If you won’t follow this rule, your flight would end up before takeoff as a failure would be very likely to occur.

    The engine temperature affects the startup behavior too. For example, a cool engine will require some priming before startup while a warm engine will be more prone to be flooded by fuel.

    That’s it! The main mission of REP, apart having fun, is learning more about our planes, right?

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    REP: Landing gear and brakes

    The Reality Expansion Pack is going to provide many features to X-Plane 10. In the other posts I’ve told you about the engine. Since REP goes a long way over the “simple” and “uncomplex” engine simulation, now I want to tell you more about some of the other systems.

    The landing gear

    The landing gear is simulated not only through its physics but also through a variety of sounds.
    When you touch down you hear wich tire touches first thanks to the provided stereo sounds.
    Also, a landing gear may affects the wind sounds. On the C210 you will hear the difference between fliying with the gear up rather than the gear down.

    A Cessna 210M retracting the landing gear

    A Cessna 210M retracting the landing gear

    Also remember that, on some planes, actuating the landing gear may affect the drag. On the C210M, for example, the gear valves open while operating the landing gear. Also, the landing gear rotates while being retracted or extended. This creates a lot of drag while the landing gear is going up or down so you have to keep a little bit of speed after takeoff before retracting the landing gear.
    The drag feeling is even more strong on a plane like the C172RG where you don’t have a powerful engine.

    The braking system

    Speaking of the landing gear, there’s also something else to say about it: usually it’s provided with a braking system.
    The brakes are modelled so the warmer they are, the less they brake. Also, you can hear them squeaking when at low speeds.
    The best way to brake on a General Aviation airplane is to press the brakes for few seconds then release them. After few seconds repeat this operation. This will allow the brakes to cool down.
    Sometimes, if you have enough runway available, you may also let the plane roll and speed down by itself.

    The latest releases of X-Plane 10 now support the spring loaded nosewheel steering. This really enhances the realism of the ground behavior of many Cessnas, such the C210, requiring to use the differential brakes to steer the plane while on ground.

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