Introduction of what?
TCAS what or is it ACAS?
Oops, that starts already with a confusing sentence. These systems are referred to as TCAS II (Traffic Alert and Collision Avoidance System) in the United states and ACAS II (Airborne Collision Avoidance System) internationally.
Where could we get our information from since the worldwide TCAS sources are so conflicting? We could look at the JAA (Joint Aviation Authorities) or the FAA (Federal Aviation Administration) or even NASA, but finally I found an article at the ALLSTAR Network (Aeronautics Learning Laboratory for Science, Technology and Research), written by Robert Ricker. Probably this could offer us some information when it comes to TCAS and its evolution so let’s see what they say about TCAS:
Building on this and other work, the FAA launched the TCAS program in 1981. TCAS is a relatively simple system to understand. Basically, the system identifies the location and tracks the progress of aircraft equipped with beacon transponders. Currently, there are three versions of the TCAS system in use or in some stage of development; TCAS I, II, and III.
TCAS I, the simplest of the systems, is less expensive but also less capable than the others. It was designed primarily for general aviation use. The TCAS I transmitter sends signals and interrogates Mode-C transponders. The TCAS I receiver and display indicates approximate bearing and relative altitude of all aircraft within the selected range, usually about forty miles. Further, the system uses color coded dots to indicate which aircraft in the area pose a potential threat. This is referred to as a Traffic Advisory (TA). When a pilot receives a TA, it is up to him/her to visually identify the intruder and is allowed to deviate up to + 300 feet. Lateral deviation is not authorized. In instrument conditions, the pilot is required to notify air traffic control for assistance in resolving the conflict.
TCAS II on the other hand is a more comprehensive system than TCAS I. This system was required to be installed on all commercial air carriers operating in the United States by December 31, 1993. It offers all of the same benefits but it will also issue a Resolution Advisory (RA) to the pilot. In other words, the intruder target is plotted and the system is able to tell whether the aircraft if climbing, diving, or in straight and level flight. Once this is determined, the system will advise the pilot to execute an evasive maneuver that will deconflict the aircraft from the intruder.
There are two types of RAs, preventive and positive. Preventive RAs instruct the pilot not to change altitude or heading to avoid a potential conflict. Positive RAs instruct the pilot to climb or descend at a predetermined rate of 2500 feet per minute to avoid a conflict. TCAS II is capable of interrogating Mode-C and Mode-S. In the case of both aircraft having Mode-S interrogation capability, the TCAS II systems communicate with one another and issue deconflicted RAs. Since this system costs up to $200,000 per aircraft, manufacturers have built in an upgrade capability to the next generation TCAS III.
Without going too much in detail, the current TACS II/ACAS II is version 7.1. It has a lot of improvements over the previous version 78.0 but because of the complexity we leave this item open. Whenever you’re interested, follow this link to the EUROCONTROL website for detailed TCAS II 7.1 information.
TCAS III will be virtually the same as TCAS II but will allow pilots who receive RAs to execute lateral deviations to evade intruders. This will be possible because the directional antenna on TCAS III will be more accurate and will have a smaller bearing error. There are also hopes that the new antenna will cut down on false alarms since it can more accurately determine an intruder’s location. Another upgrade that is proposed has to do with the Mode-S data link. Through this link, a system will be capable of transmitting the aircraft’s GPS position and velocity vector to other TCAS-equipped aircraft thus providing much more accurate information however, this version is not yet implemented and under development. There are even thoughts skipping version III and moving on to TCAS IV.
Is this all? No, there’s much more to tell you about this system, and together with the many FCOM’s (Flight Crew Operations Manual) and AMM’s (Aircraft Maintenance Manuals) I own, I could write a review of over 10.000 words only about the real TCAS system with all its ins and outs. However I don’t think that’s the idea.
The idea is to check whether the DBS Studio add-on software is worth buying and thus if it’s doing what they promise. With the software in one hand (main program and two updates) and the manuals in the other (two Acrobat files) I should be able to see, test, and convince myself of this add-on instrument.
As usual ….. the installation and documentation section
The main installer is, as I know from DBS, straightforward and after the installation is finished, you need either to activate the software online or offline. I’ve chosen for the online activation and after 6 hours I got the necessary data/email, which should be inserted within FSX via the Add-ons – DBS TCAS menu. Don’t forget before continuing to have a look on the DBS website for the two available updates. I can tell you that these are absolutely needed. They’re not big – just 130Kb and 145Kb for respectively FS9/FSX update I and II - thus before you know you’ve downloaded them and have them installed.
As usual find via the Start menu button a DBS Studio – TCAS folder with the two Acrobat files. That’s all. No uninstaller or link to the website. When you don’t want to access these Acrobat files via that way, then just look on the desktop and find there two shortcuts from the same files. Before we move on to the Documentation part, let’s have a quick look at the actual DBS TCAS instrument. Find below a few screenshots of the DBS TCAS instrument.
It comes with two documents; how to activate the product and a user guide. When you’re new to DBS products, then a procedure manual of how to activate your product is welcome. It’s not difficult but for newcomers, it’s useful.
The user guide should help you in how to install a DBS TCAS indicator in your cockpit and according to the text this should fit in every FS2004 and FSX airplane. I haven’t tested the DBS product with FS2004 but for FSX I can tell you that it doesn’t automatically install in every FSX airplane and then in particular the add-on airplanes. More about this later. Furthermore it would be an idea if DBS had added this into this manual a short description of what TCAS is and some history.
the manual is just one page and that’s it. A valuable
part is how to add the DBS instrument into your cockpit however,
with certain add-on aircraft it doesn’t work at all and manual
input is needed by editing the relevant pane.cfg. Unfortunately,
this is not a normal way for those who haven’t any experience
with editing cfg files. More about all of that later on when it’s
time to test the DBS TCAS integration.
Let’s see if I can add TCAS!
For FSX related aircraft the answer is unfortunately YES and NO. Oops, I do make it complicated. Why? I’m sorry for that but it seems it isn’t always possible to connect the DBS TCAS indicator to the aircraft of your need.
Anyway, connecting a DBS TCAS indicator is done as follows:
I don’t think I’ve forgotten anything in relation to this Cessna 172SP. After you’ve added it, reloaded FSX (or FS9 which is in this case the same) it’s integrated into the 2D and VC instrument panels. You’re even able by clicking on the TCAS instrument, to get a floating instrument. There’s no range option available but further on the instrument works, although I haven’t checked the TA and RA functions, but that’s for later.
Let’s move on to our next default FSX victim, the Mooney Bravo with the old fashioned instruments. The same here; after you’ve added the DBS TCAS instrument, reloaded the aircraft as described previously or you go to Aircraft -> Select Aircraft -> and reselected the Mooney, the default round VC indicator is replaced with the squared DBS TCAS indicator, which is applicable for both the 2D and VC cockpits. This time the instrument does have the range buttons on the RH side and the indicator is again clickable for a floating version.
It seems the integration works fine but what happens when you’ve selected the Mooney Bravo with the G1000 Glass Cockpit equipment? Let’s try it and see if the result is stunning or not ……! Don’t forget that you need to load the DBS TCAS instrument into this cockpit or shall I say this panel.cfg file. I know, you don’t need to add this instrument manually in the panel.cfg file, but you need to keep in mind that this is a different panel.cfg file than the previous discussed old fashioned cockpit file.
Ok, I loaded or added it into the Mooney Bravo G1000 version, did an aircraft reload and oops, there’s no FCAS instrument installed which is when thinking of it, normal since the instrument panel offers – apart from three instruments on the right – only two MFD units however, via menu Views -> Instrument Panel, there’s a new option added, the DBS TCAS. When selecting this, you’ve got your floating TCAS instrument. Does it work and alert the pilots, that’s discussed in detail later on.
Up next, the default FSX airplane, the Bombardier CRJ700. When I tried loading the DBS TCAS instrument, it seems I did this already before because a pop-up window tells me that TCAS is already installed in this panel (read aircraft) and do I want to remove it? No way, but this is a good example of what happens when you try to load it while it’s already loaded or written into the panel.cfg file, a message warns you of your action. I leave it like it is which also means that there should be a DBS TCAS option available via the menu Views – Instrument Panel and yes, there it is. When I write “there it is”, it was in my case added as a floating instrument in the 2D cockpit. When you switch to the VC there’s nothing thus you need to reselect it via Views – Instrument Panel. Anyway, the moment the VC panel is loaded, you’ve got a floating TCAS within the VC.
In between conclusion; altogether no problems at all with default instrument panels, but what about with add-on airplanes? Our first add-on will be the Captain Sim 757.
Adding the DBS TCAS instrument into the Captain Sim 757 is done in the same way as described before. I’ll refresh the steps to follow after you’ve loaded the CS airplane, so first select from the menu Add-ons -> DBS TCAS – Add to Panel. Unfortunately this gives a failure “TCAS installation to panel failed” message. This means that the CS 757 panel.cfg file isn’t modified and thus no TCAS instrument is added. This is confirmed after a reload without having a DBS TCAS option in the Instrument Panel menu section. For beginners there’s no other option however, it’s possible to add this TCAS instrument manually in the respective panel.cfg file, although this is not a normal procedure to follow when you’ve got no clue of how and where to install it. Therefore, I leave this possibility open for the moment.
We take another add-on aircraft model. This time we try it with the Flight1 Level-D 767. Let’s cross our fingers if it works with this one. Adding via the FSX menu the DBS TCAs instrument seems without problems and after a reload, there’s of course no instrument added into, for example, the 2D panel. The standard VS indicator is still in its place and covered with a DBS version but via the Views – Instrument Panel menu, we’ve got the option to select the DBS TCAS instrument as a floating version in either the 2D or VC cockpit. It seems it works great and by the way, the instrument has got a TEST button fitted in the LH upper corner. It seems my in-between conclusion will be positive in relation to this add-on airplane.
Just follow the steps and you’ve got a floating TCAS instrument, if the add-on airplane is already equipped with a TCAS by its own. Remember, the DBS TCAS instrument is especially for those planes which don’t have it at all or it’s not simulated. Honestly, I’m not that familiar with the Flight1 Level-D 767 and therefore it’s difficult to say if the standard installed TCAS offers the same functionally as the DBS version. Anyway, that’s what’s important; adding the DBS TCAS into the panel.cfg is easy and straightforward.
Next victim, the Wilco Publishing Airbus Volume 2. To start with, I’ll take the first available model in the FSX list, the Airbus A330-200 with GE engines. Adding the DBS TCAS instrument as explained earlier works and after an Airbus reload, there’s of course no TCAS indicator on the main panel but there’s a floating version available when selected via the Views – Instrument Panel menu.
In other words, the DBS TCAS instrument can be inserted in the Wilco models, which is for all the models the same. You can only ask yourself if there’s a need to add the instrument in this type of aircraft. As far as I can see, the Wilco model is standard equipped with a functional TCAS system, which is, when active, shown on the PFD and ND. That means when the built in TCAS works, there’s not really a need to add the DBS here. Anyway, the Wilco Volume 2 model panel.cfg files are straightforward and modified by DBS.
One last model from Wilco/feelThere, the Embraer Regional Jets. I’ve chosen for the ERJ 135, but one of the others could do as well. Trying to add the DBS TCAS to this model doesn’t work. The same as we saw before; a failure “TCAS installation to panel failed” message is given which means the panel.cfg file is not changed and thus no TCAS is added. Is this a problem for this aircraft type? Not at all since the whole Wilco/feelThere Embraer series are standard equipped with a TCAS II installation thus there’s no need to add this DBS indicator. It was worth trying it!
I didn’t cover all the add-on models because that’s too much but after testing several add-on models I think I can conclude that in some cases DBS can modify the relevant panel.cfg and in some conditions it can’t. As said before, if you wish you can change the panel.cfg file by yourself with the result that a DBS TCAS floating indicator can be called-up. For the floating indicator and the necessary panel.cfg modification, I’ll give you an example but remember, the used “Window=x” number depends on the other available ones.
here an example of adding (bold) it into the Embraer
Regional Jet CRJ 135.
we manually added windows title “Window16”, we
also need to add the settings for it. Therefore either at the end
of the panel.cfg file or after the Window15 section, we add the
When you’ve done this, save the panel.cfg file and restart FSX and load the Wilco/feelThere model. Remember, there’s no need to add this instrument via the Add-ons -> DBS TCAS – Add to Panel since during our previous attempt we got a failure message and we’ve just added it manually. Ok, FSX is running and we’re sitting in the Embraer Regional CRJ 135 cockpit.
A quick look in the Views – Instrument Panel shows that there’s an additional option available, our DBS TCAS. Selecting it gives us a floating DBS TCAS instrument although the need to visualize this in a cockpit having standard TCAS II installed/integrated, is useless. Ok, the idea is to show you and in particular flight simmers who do not have much experience in manually adding items in the panel.cfg file. One last note regarding the above; remember that under section [Window Titles] your number is always the last number plus 1. Therefore the default number in this panel.cfg file is 15 and thus 15+1 is number 16. This is the same for the [Window16] section. The number between the brackets should be the same as the number in the Window Tiles section. That’s all and before you know, you’ve got a floating instrument option.
Time to see what the outcome is of the instrument and what you see and hear.
This is what I can show you
Although the DBS TCAS instruments are slightly different from each other depending in which airplane they are fitted or should I say which gauge file is requested, the general idea of this add-on software is to warn you about other traffic and if needed, helping you with what to do. With that said, it’s time to jump into the default Beechcraft Baron 58 and fly in an area with lots of other traffic to see if it’s working. That it works, that’s something I believe but makes sense when you or others approach each other and conflicting situations appear.
I’ve placed my plane somewhere in the San Francisco area (KSFO) and I must admit that it works great but what does great mean? Ok, the implemented DBS TCAS shows other airplanes in the surrounding area, depending on the RANGE selector. Too close to other aircraft results in a changed color difference of the other. There’s also a RA advisory to climb or descent.
This is not only visible within the TCAS indicator but an aural warning helps you understanding what you should do. Although pictures don’t say enough, with the help of explanatory notes you should get a good idea of what happens, so please join me on my dangerous VFR flight over the San Francisco Bay.
The moment you’re coming too close, either a pre-warning tells the pilot that TRAFFIC is ahead and thus not only visible on the TCAS indicator but a message as well. Other aural messages that could pop up are for example “CLEAR OF TRAFFIC, MAINTAIN VERTICAL SPEED, INCREASE CLIMB, TRAFFIC” (like an initial alert) etc. Some are very clear like CLEAR OF TRAFFIC, which means no more than the dangerous flight situation is gone while for example MAINTAIN VERTICAL SPEED means no more danger when you maintain this vertical speed, the critical situation or air collision will be solved by itself.
The only thing that isn’t explained is what all the symbol colors and shapes mean, so it’s time to dig on the Internet and find for you some additional information since DSBS Studios doesn’t offer this vital important information.
Find below the symbols used in the DBS TCAS indicator, with courtesy from Honeywell’s TCAS II/ACAS II User’s Manual:
- An open white diamond indicates that an intruder’s relative altitude is greater than plus or minus 1200 feet vertically or its distance is beyond 6 nm range. It is not yet considered a threat. For example; next of the open white diamond there’s indicated -17?. This means the other aircraft is 1700 feet below your own altitude, climbing at 500 feet per minute or greater
- A filled white diamond indicates that the intruding aircraft is within plus or minus 1200 feet vertically and within 6 nm range, but is still not considered a threat. For example; indicating -10? means that this intruder is now 1000 feet below your aircraft and climbing.
- A symbol change to a filled yellow circle indicates that the intruding aircraft is considered to be potentially hazardous. Depending on your altitude TCAS II will display a TA when the time to CPA is between 20 and 48 seconds. For example; indicating -9? means that the intruder is 900 feet below your aircraft, climbing at 500 feet per minute or greater. A voice announcement is heard in the cockpit. Under normal conditions a TA will precede an RA by 10 to 15 seconds. The crew should attempt to gain visual contact with the intruder and be prepared to maneuver should an RA be sounded 10 to 15 seconds later. The crew should take no evasive actions based solely on the TCAS II display.
- A solid red square indicates that the intruding aircraft is projected to be a collision threat. TCAS II calculates that the intruder has reached the point where a Resolution Advisory is necessary. The time to closest approach with the intruder is now between 15 and 35 seconds depending on your altitude. The symbol appears together with an appropriate audio warning and a vertical maneuver indication on the RA/VSI. Voice announcements are listed later in this section. For example; indicating -6? means that this aircraft (intruder) is now 600 feet below your altitude and still climbing. A synthesized voice announces a vertical maneuver command. The pilot should smoothly but firmly initiate any required vertical maneuver within 5 seconds from the time the RA is posted, using pitch cues or the Vertical Speed Indicator as appropriate. An intruder must be reporting altitude in order to generate an RA. Therefore, the RA symbol will always have an altitude tag.
Is there anything more about this? Not really since it works for every aircraft in the same way. Ok, depending on the aircraft where it’s fitted into, the instrument offers no RANGE selection, or it does and with some there’s even an indicator TEST button simulated, but like I said before, the principle is all the same. If you fly with a Cessna 172, a Learjet or a Boeing 747 etc., all produce the same indications and aural warnings.
Summary / Closing Remarks
Is this then the end? Yes, I’m afraid it is. Looking at this add-on software I must say, when you’re flying mainly with default FS9/FSX airplanes, it’s worth buying it. It doesn’t cost much more than $14.95 (€9.50) and it offers real TCAS information in those default airplanes. I’ve you’re flying online at IVAO; I believe the IVAP client offers a built-in TCAS but I’m not sure what and how it looks. Anyway, for this small amount of money it’s worth the price. However, when you only fly add-on planes that are equipped with an integrated TCAS functionality, then there’s no reason for buying this add-on in my opinion.
After you’ve installed the main program as well as the two updates, the DBS TCAS instrument is working perfectly and is well integrated in the cockpit panels, if applicable. In some configurations there’s nothing integrated or replacing the default Vertical Speed indicator, but instead you can select a floating TCAS instrument.
I’ve tried to compare the DBS TCAS instrument functionality (TA/RA) with built-in add-on versions, and apart of the possible different colors, it seems to do the same and thus I assume that it’s working as it’s supposed to. The DBS TCAS instrument is directly available and operative and doesn’t need to be switched ON apart of – with GA airplanes – the AVIONICS switch. Compared to, for example, the Embraer CRJ 135, it works straightaway while the Embraer TCAS function need specific settings before showing some information on the MFD (Multi Function Display).
Overall impression: not bad at all and keeping the price in mind and what it’s intended for, I think it’s a useful add-on package. But again, when you’re flying only modern add-on packages which include TCAS II functionality, then there’s no reason to buy it unless you want to save the world!
For those who would like to know a little more than what I’ve reported in this review regarding TCAS in general, please find some links to several institutes who offer TCAS/ACAS information.
- EUROCONTROL Airborne Collision Avoidance System
What I Like About TCAS
What I Don't Like About TCAS
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