Adding "New" Aircraft to Tower

So, you'd like to add your favorite aircraft/airline to your copy of Tower.  It isn't hard, but, as you'll see, there are some limitations.

1. First, you have to "create" the visual model for your aircraft.  Unfortunately, Tower uses its own proprietary graphics modeling, so you can't create an aircraft using Flight Shop or even a Flight Simulator 4.0 utility.  Instead, you have to decide which existing model is close enough visually to substitute for your desired aircraft.  My ORD mix of aircraft includes the Airbus 300 and the Boeing 777, both using the Boeing 767 model.

Example:  Virgin Atlantic's new Airbus 340s are getting pretty common, and you're probably likely to spot one at ORD, so let's add one.  My nominee for closest model is the Boeing 707; sure its 50 feet shorter, but its 4-engined wing is pretty distinctive.

2. Make a copy the existing 3D model and rename it exactly as you want it to appear in the flight strip.  The 3D model files (*.DBT) are located in C:/Tower/Graphics/Models.  Then, add the model to the MODELS.INI file using NOTEPAD (or some other text editor):  Add 1 to the "Count=" for each aircraft you are adding.  Go to the bottom of the aircraft section and add ACType##=<name of aircraft file>.DBT with the total number of aircraft models substituting for ##.  Save the MODELS.INI file and exit NOTEPAD.  The aircraft is now ready for use at any of the three airports.

Example:  Copy the B707.DBT in the C:/Tower/Graphics/Models directory.  Rename the resulting "Copy of B707.DBT" file "A340.DBT".  (Or go to a DOS window and "copy b707.dbt a340.dbt".)  Now, open MODELS.INI with NOTEPAD.  Add 1 to the "Count="  and add the the line "ACType##=A340.DBT".  (Don't forget to use the number of aircraft models for ##.)  Save and exit.

3. The new aircraft needs to be added to a number of files for any airport at which you wish it to appear.  Again, you need to copy the information relevant to the original model for each file.

A) Open the *.INF file, copy the series of coordinates for the original aircraft you copied above and paste them back into the file.  Then change the "Type ####" line to reflect the new aircraft.  Save and exit.

B) Open the *.PRF file, copy the performance information for the original aircraft, and, again, paste it into the file.  (You'll have to use WORDPAD because of the file's size.)  This file has specific sections for types of aircraft (Single, Twin, Airline, Heavy, etc.) so make sure you insert the new aircraft in the proper section.  (This will correspond to the section you place the aircraft's callsign in the *.CPL file.)  Change the Type name to reflect the new aircraft, save, and exit.  (You can change some of the parameters, but most have little or no effect on the aircraft's behavior.)

C) Open the *.TYP file and do essentially the same thing as in "B" including making sure the new aircraft is placed in the correct section.  (This file doesn't seem to really be used by Tower, but it complains if the aircraft does not appear in the file.)

A) Open the ORD.INF file, mark the series of coordinates for the B707, COPY them, and then PASTE them into the file just below the B707.  Change the "Type B707" line in the pasted portion to "Type A340".  Save and exit.

B) Open the ORD.PRF file, mark the performance information for the B707, COPY, and, again, PASTE it into the file -- but this time, move down to the section marked "[Heavy]".  PASTE the copied portion below the Heavy section divider.  Change the "Type: B707" name to "Type: A340", save, and exit.

C) Open the ORD.TYP file and do essentially the same thing as in "B" including making sure the new aircraft is placed in the [Heavy] section.  Save and exit ORD.TYP.

Example: Well, your A340 is ready to go, but whose going to fly it?  Let's pretend that United purchased some Airbus' to compliment their fleet of Boeing 777s on their long range flights out of their Chicago hub.  Open ORD.CPL and go to the [Heavy] section.  Replace the "DC10" for flight "UAL116" (#169) with "A340".

From:  "UAL116 DC10 169 " Into: "UAL116 A340 169"

New Airlines and Callsigns

But what if you want to assign a new aircraft like the A340 to a airline that doesn't exist in Tower.  No problem.  You can easily change the airline designators and flight numbers int he *.CPL file for each aircraft to reflect some new airlines.  For example, you might change some UAL flights to SWA or ASA for Southwest or Alaska Airlines respectively.  In our continuing example, you'd want to change "UAL116" to "VIG116" for Virgin Atlantic Airlines.  The flight will now dutifully appear as such, but will still say "United One Sixteen" when it appears.  You might be able to live with that, still using the flight number, but mentally ignoring the "United" part.

Using this method, you can add as many new airlines as you wish, changing the callsigns for individual flights.  You don't need to change any other files, because although many of them contain information about the specific airlines, Tower doesn't seem to use any of that information.  (More features that never made it into the release version of Tower.)

But what if you wanted to hear the correct airline callsigns?  Well, if you're ready for more work, you certainly can do so.

Changing Callsign Voices

The voices for each callsign are located in callsign.voc which is a Sound Blast Voice Files -- [Sample rate 8000, mono, 8-bit, PCM, unsigned], and are in the order listed in *.cpl.  For example, United 116 appears as the 169th voice phrase in the file.  Although they are indexed by number, Tower relies on the length of each phrase to determine which phrase to use for each flight, so any replacement you make must be exactly the same length as the original being replaced.  (Again, always make backups of files you are planning to modify so when you screw them up, you always have the originals to go back to.  In fact, you might consider making an entirely different copy of Tower on your hard drive to experiment with.)

Example: Let's change "United 116" to "Virgin 116".  Open callsign.voc with a good sound file editor (I use Cool Edit).  Find the phrase for UAL116 -- its toward the end of the file.  Use the mouse to mark/highlight the section of the phrase that says "United."  Your editor should be able to tell you exactly how long the file is in fractions of second.  Whatever you replace that sound with must be exactly the same length in time.

Now, you'll need a replacement sound.  Using your sound editor/recorder (in another window if possible), record the phrase "Virgin".  You might use your own voice, or, if you are adventurous, you might use a UHF receiver to listen and record actual pilot voices at your local airport.  Once you've recorded the sound, mark that portion you wish to use.  If it is the wrong length, you have to find a means of making it the same length as the section you want to replace.  If it isn't long enough, you might include a little bit of blank space, or cut out any blank space if it is too long.  Or you can use your sound editor to lengthen/shorten (strech/shirnk) the portion, hopefully being able to maintain the sound's original pitch.  Once the portion to copy is the right length, COPY the new section and PASTE it over the original sound.

In our example, highlight "United" in one sound editor window, then highlight "Virgin" in another.  Once you've made sure their the same length, COPY "Virgin" and PASTE it over the "United" in the other window.  Save the VOC file (as "raw data" if asked).  Now highlight the entire phrase, play, and you should hear "Virgin 116".

To be even more realistic, if you are using a UHF scanner/receiver and record the pilot of a Virgin flight say his entire callsign, you could use that phrase to replace the whole "United 116".  Then make the change in the *.CPL file to reflect the new callsign (e.g. "Virgin 278" sound and "VIG278" for the *.cpl file.)

Congratulations, you've added a new aircraft, new flight, and new callsign to Tower!  Now, whole new fleets of aircraft await!

Tower is copyrighted 1995 by BAO Publishing and is distributed by Apollo.  Flight Simulator is copyrighted by Microsoft.  All trademarks and rights are reserved by these entities.
 

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