Air Traffic Control Commercial Utility Review
VoxATC - Now You're Really Talkin'
Contributed Review by Zane Gard

Product Guide
Program Author:
Tegwyn West
VoxATC is an ATC add-on for FS2004 with integrated voice recognition. You talk to the controllers using standard ATC phraseology and what you say will be heard. Requests must be properly constructed and instructions complied with and read back correctly.
D/L Size:
D/L or CD
Reviewed by: Zane Gard, Guest Reviewer
Commercial Review Rating Policy: As this is a contributed review the product is unrated.


The VoxATC Development Story

There are voice control programs and then there are true voice recognition programs. For many years now we have had voice control programs that will allow various keystrokes to be handled by voice. These are best used to emulate a co-pilot that obediently follows your voice command with the appropriate action. Many diehard simmers have tried to use these programs to create an interaction with air traffic control that is more realistic than pushing the upper row of numbers on the keyboard. The problem that confronts us though is the order in which Microsoft's Flight Simulator provides for selections in the ATC window varies too much for a single voice entry to always mean the same thing. Some really creative users have programmed different ways of saying the same thing to activate different numbers. While this does allow full voice control of ATC in the sim it is not a good habit for real life radio communications and let's face it, if you were actually flying and needed to make a request or respond to a radio communication you wouldn't have the time to be thinking which nearly identical phrase to use. The most usable option I found was using a readily available voice command program and saying the number corresponding to the screen selection desired.

It was a surprise for me that while Microsoft included speech generating and recognition software with its word processing programs it did not even make an attempt to integrate it into the last two versions of its flight simulator. There is evidence in the configuration files used in FlyII that the late Richard Harvey was trying to program the possibility of speech recognition into his now discontinued sim. There just was no more time and the technology, at least for a mass marketed sim, just hadn't caught up yet.

That is about to change and thanks to a nearly five year effort on the part of Tegwyn West, a software engineer in the UK. During Mr. West's training for his pilot's license he found that one of the hardest parts was getting the radio procedures down. He had tapes and training programs but found that while he could complete those courses at home everything was different when you combined talking on the radio with operating the aircraft. What he needed was a way to combine the cockpit workload with radio communications training.

In 2000 he started working on a program that would use voice recognition and work within Microsoft's Flight Simulator. By the spring of 2001 he had completed the first beta for FS2000 which covered a small area of the mid-western US and allowed for VFR flight. Because this program was designed from the start to use voice recognition, intelligent agents were programmed in as pilots and controllers so it would accurately model a virtual airspace. All of the various agents and software infrastructure were developed to allow for a conversational interface which would lend itself well to using voice recognition.

A FS2002 version was developed the next spring which also made IFR flights possible and by fall of 2002 VoxATC would handle any flight you could make in FS2002. There was a brief flurry of press releases on the simulation sites in 2002 and some talk in the forums but the program remained underground in perpetual beta, so to speak.

By the summer of 2004 an alpha version was developed that would work with FS2004. The numerous changes in the way airports and navaids are handled between FS2002 and FS2004 meant the old program wouldn't just transfer over. Beta testing continued through the fall, and January 2005 marks the month that flight simulation enthusiasts truly have something to talk about.

About reviewer Zane Gard

I am a Chiropractor in Beaverton, Oregon and have been a licensed pilot since 1986. My earliest memories are of flying with my father as early as 1965 (I was two!). Built my own homebuilt aircraft (an American Aircraft Falcon XP) was featured in Sport Pilot in 1987 and 1993. I have logged time in everything from my little homebuilt to a Lockheed C-130 (long story). I have been involved in flight simulation since 1986 and have owned almost every sim produced—I still enjoy using FlyII in addition to FS2004.

My home simulator uses two monitors (as discussed in the article) CH USB Yoke, pedals, throttle quadrant and an Aerosoft ACP Compact (which I may cover in a future review). I believe that a good home simulator can help keep a pilot proficient as long as you remember the shortcomings and really try not to learn bad habits that you have to unlearn when really flying.

My involvement with VoxATC has been as a beta tester during the final month of development. I helped point out areas that needed improvement in ATC and tested the program on numerous payware aircraft to find any incompatibilities (which have, for the most part, already been fixed). I am most excited about this particular program because it addresses an area that I found myself lacking when I went for my last BFR... radio communications. I had not been flying for a few years and my frequent use of the simulator had made me quite lazy when it came to keying up and talking, something that this program will certainly prevent.

Installation and Setup

Enough about the history and development… what about the program? When you first enter the VoxATC site you will find a description of the program, the entire manual is also there for you to read with excerpts of the kind of phrasing you will encounter in the program as well as a FAQ section. You are allowed to download a demo of the program but you will have to register for this. Actually this is the installation program, it's just not fully activated yet. The demo will function for 30 days and allows for flights between three US airports, KMCI, KOMA and KMSP and includes three situations to start you out on flights with flightplans between these airports. If you are still using dial-up take note, this is a 51.2 megabyte file so you might want to opt for purchasing the CD available through the RC Simulations site.

After installing the VoxATC program it will automatically run an indexing program that will look through your scenery and aircraft files to customize it to your particular installation. If you add or modify any aircraft or add additional scenery you will have to run this indexing program again so that VoxATC will recognize the changes that you made.

This program uses Microsoft's SAPI 5 speech engine, the current version being 5.1 which is included in the VoxATC installation file. This was also included in Windows Office XP but with only one voice so VoxATC will add the other voices. In the VoxATC manual you will find instructions on the settings you should use for best results with the voice recognition. You will also need to have Pete Dowson's latest version of FSUIPC installed for the program to work.

Next you should go to the flight plan trainer. Go through the General Training first. Then you can browse for each of the three example flights and make sure you have them trained for your voice as well. It is also a good idea to run this trainer through a created flight if it includes flying to an airport with a peculiar name such as Coeur d'Alene. The readback sounds funny and if you haven't trained for your pronunciation it usually won't be recognized. You will also notice in this dialogue box that you can enter a call sign. For airliners you can enter an airline name and a flight number (numbers only). For general aviation use you have to enter a "N" followed by four digits and then an alphabetical character. At present the program will only accept general aviation call signs in this fashion. There are plans to allow for more variation in call signs in the future; for now if you attempt to enter an "illegal" call sign the dialogue box will not accept it and a red message will appear with help to correct your mistake.

If you are using a joystick or yoke with buttons you can assign two of these buttons to work with VoxATC. You should have this set up before starting your flight. The menu selection can be found in the same drop down menu you just used for flightplan training. There are keyboard keys that can handle these same functions but having them on your joystick/yoke is much handier. The most important one will be the PTT (push to talk) that you have to press to transmit on your radio; on the keyboard this is the space bar. The second will allow you to ident your squawk code from your transponder; on the keyboard this is handled by the <i> key. In real-life flying an ident is a common request and it sends a stronger signal from your transponder so your aircraft is easier to identify on a controller's radar screen.

Flying with VoxATC

Now that we have the voice recognition trained and joystick buttons programmed, let's go ahead and try to make a flight. The three flights included in the demo have walkthroughs included in the manual as well as on the website, so we are going to make and fly a flightplan that only the full version will do. First thing to understand is that this program operates from a saved flight with attached flightplan. If you are used to creating a flight by selecting an aircraft, then loading up a flightplan to go with it you are going to have to add two additional steps. First you will have to save the flight, then you are going to have to go to the saved flights menu and select the flight you just saved, then press the "fly now" button. If the flight you are planning is going to include a SID and/or STAR you are going to have to complete those instructions before loading up your flight as well.

For our review flight let's make the return flight for the Malibu Meridian video that Flight Video Productions released last year. If you recall the video was for an IFR flight from Boeing Field Int'l (KBFI) to Bellingham (KBLI) in Washington State. First we'll create the flight in FS2004's flight planner and save the flight. Since there is a common departure used for southward flights from Bellingham we are going to also set up a standard instrument departure or SID. After the flight is saved we will use the VoxATC "Sid Star Setup" to insert the departure for Kieno 1 using the KIENO intersection as the end waypoint with a 3,000 foot crossing altitude and using the Paine transition just as published. You will note from the SID & STAR Setup window that you can also enter an arrival using a start and end waypoint, each with altitudes assigned by ATC or not. Since this is a short flight we are opting out of the arrival option and will use VoxATC's own vectoring for final.

After pressing the "OK" button in the "SID & STAR Setup" window we are back to FS2004 and can go ahead and press the "Fly Now" button. After the flight is loaded and the aircraft is started I go to the FS menu with the <alt> key and select "Options" from the drop down menu under VoxATC. A menu box will appear and from here you can enter your callsign; for this flight we will use N5279A. There are also boxes to toggle enroute holds and enroute traffic instructions if you want them included in your flight. For this flight we will toggle for traffic instructions but leave the enroute hold unchecked. You can also use the sliders to set your traffic density, speech volume and average speech rate. We select "OK" and once again hit the <alt> key to bring up the FS menu again, this time selecting "Enable VoxATC" from the drop down menu under VoxATC. At this time the VoxATC prompting box will appear letting you know the program is initializing.

On my system I use two monitors, the larger for my main flying view, the second is relegated to navigation/weather duty. I will usually display FSMeteo and Jeppesen SimView, and I'll toggle FSFlightmax over these for the enroute phases of flight. The VoxATC prompting window fits perfectly above the FSMeteo window so I can keep all this information on a separate screen. For users with a single monitor the prompting window can be brought up by hitting the <o> key. This is the same key that is assigned to toggle the strobes in FS, so if you are used to using the <o> key to activate your strobes you might want to reprogram your FS assignments to handle strobes with a different key. At present there is no way to change the default VoxATC keys.

A new experience in ATC interaction...

After listening to ATIS and setting the altimeter I contact Ground for clearance instructions. I get a clearance including the name of the departure procedure I am assigned and the name of the transition assigned—this is one of the first ATC programs to do this in FS2004 and it is how a clearance will get read to you in real life. You have to read back the clearance in the proper order and if you get stuck there's always that prompter to remind you of what to say. I then contact Ground for taxi instructions and am told which runway and which taxiways to use. It helps having an airport diagram because the default ATC's little pink dashed line is not available with VoxATC. Jeppesen's Simview has most larger airport charts but a freeware program that can come in very handy is Manuel Ambulo's "Airport's Chart Viewer" (downolad from the Avsim Library); it will work at any airport in FS2004.

Since this flight is using a published departure procedure (SID) you are expected to fly that routing. If you start a flight without a SID you will be given instructions on which headings and altitudes to fly until clear of the airport service area. After takeoff we are handed off to Departure and as we approach the Keino intersection we are cleared to a higher altitude and told to proceed to our next navaid which is given by its name "Paine Everett." On a longer flight plan where you will be staying on a victor or jet routing you might be given the name of the routing so were I flying further south I probably would be told to "fly direct Paine Everett then join Victor Two Three" instead of the direct to "Paine Everett" routing.

Center finally clears us for our cruising altitude of 11,000. All the time there is background chatter of other GA aircraft and airliners getting altitude changes and routings/speed assignments so the overall affect is of being in a cockpit and hearing chatter specific to the area you are flying, not canned chatter that after the first few flights becomes all-too-familiar sound bytes.

Upon reaching the Paine VOR we are told to contact Approach and given instructions for landing at Boeing Field. Now when first given these instructions you have the option of asking for a different runway, a visual approach or any of the published approaches available for the runway you are assigned. So if there is a NDB approach, you can ask for it. If you take the ILS runway approach you will be given vectors to final; you can request a "full ILS" to the runway and then you are given an initial vector and altitude but you are expected to fly the published routing after that. If you get too far off track the program will come in and give instructions taking you back towards the runway. While on this particular approach I was given vectors that brought me a little close to some of the surrounding foothills as you can see in the screenshot; but in a month of using the program I have never had the program vector me into a mountain or into a valley only to follow with instructions to climb to clear an obstruction. This has been purely by luck because the program does not figure in terrain elevation. If you are going to fly into an area with high terrain you would be better off using a published approach.

I have also found that the vectors to final will always bring you in to intercept the centerline at a shallow enough angle to make for a very smooth transition without having the autopilot start hunting right and left. What you will miss on short final and while on the tarmac is seeing other aircraft on the ground and in the pattern. A price for using the processor for voice recognition but I found I didn't mind the tradeoff that much. If you've got a fast enough processor you can probably turn on some AI traffic.

One thing you might find disconcerting during your approach, especially short final is the program will have a tendency to assign almost any runway to the AI voiced traffic. I have had occasion when I was on short final and an airliner was cleared to land from the opposite direction, or on an intersecting runway. The takeoff clearances for the runway you are landing on will be told to hold short and upon landing if there is traffic behind you; they will be told to go around if you linger too long on the runway. As you are touching down you will usually get an instruction to turn either right or left at the taxiway; the program will expect an acknowledgment in the form of your "N" number. Upon turning off the runway you are told to contact Ground and the frequency, then Ground will give you parking instructions. These are sometimes to a Gate, other times to the parking spaces for GA. An improvement for realism in the program would be parking assignments to an FBO and/or hangers but that would require a great deal more programming because FS2004 is not set up that way. In real life you are not told to taxi to "park seven," but you would hear "taxi to Flightcraft" for instance here in Portland, Oregon. I don't even know the names of many of the FBOs and wouldn't want to tackle writing additional files so that each airport has their particular FBOs and hangers called out by name.

Some impressions

All in all this is a huge leap forward in technology for flight simulation. The level of cockpit immersion is so different that when I go back to flying with the default ATC—and mind you I'm using Editvoicepack 3.1 with altered phrasing and MyTraffic 2.1—that it does seem like a game by comparison. I have read complaints in the simming forums about the computer generated voices that the SAPI 5 uses, this is more than made up for by the enhanced realism and I find I don't even notice the voices now. It's still easier to understand than the chatter you get from most radios and cheap headsets on rental aircraft.

My computer is an Athlon 2000XP with a GeForce4 Ti4200 128MB graphics card and 1GB DDR ram. I am running close to the minimum required computer and despite using a complex aircraft, RealityXP weather radar, FSMeteo, Jeppesen Simview, and 38DEM mesh I found the frame rates acceptable at all times. If I turn on AI traffic even to a low level the frame rates drop too drastically for my use. Those with faster processors have reported being able to bring AI traffic up to 50% although they are going to operate completely independent to what you hear over the radio.

Is this an add-on everyone should have or want? Probably not. There are many simmers that really dig investigating all over highly detailed airports, flying formation with AI traffic or just chasing them, or watching the other aircraft taxi by and then they do most of their flying in spot view with the autopilot and a FMC or FSNavigator while looking for other traffic. This program probably will not appeal to them because they will have to give up too much of what they enjoy. What this program is best suited for is real pilots and pilots in training, but it will also give wannabe sim pilots who want a better experience of what the cockpit workload is like in real life a good taste of it. Even if you don't get thrown the pipe wrenches that happen in real life. Ya just can't kill yourself in a sim!

The cost for registering the program is £30 which at the current exchange rate is pricey. There is really nothing to compare it to but pilots will frequently purchase ATC training programs. Comm 1 offers a VFR simulator for $99.95, IFR simulator for $119.95 and a Clearances simulator for $119.95. These are very intense home training programs to run on your computer and will challenge you into gaining proficiency with radio communications. None of them will give the added tension of trying to fly the aircraft as you are speaking though. That gives this program a unique advantage. Don't take that out of context, I am not putting down the Comm 1 programs, they are much more comprehensive than the speech you will use with VoxATC. VoxATC offers something that has been missing from ATC training and missing from flight simulation, by combining the two so you can do them together. I can only imagine what the future will hold for this program.


What I Like About VoxATC
  • Finally a program with true voice recognition for talking to ATC
  • Allows for IFR, VFR with flight advisories (flight following) and VFR flights
  • Ability for in-flight emergencies
  • ATC uses names for waypoints, airways and non-tower airports
  • Prompting window if you don't know what to say
  • Good radio training aid for student pilots, especially in USA
  • Easy to install and use

What I Don't Like About VoxATC
  • Needs option to select takeoff runway at non-tower airports
  • Traffic calls are not linked to MSFS' AI traffic
  • Needs a provision for alternate airport after missed approach that doesn't involve loading a new flight plan
  • Digitized voices are not as realistic as default MSFS voices
  • FAA-based terminology IS good in USA, but needs ICAO terminology for operations outside USA
  • Should automatically shut off or reload when loading a new flight


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The review above is a subjective assessment of the work of the author. The connection between the product author and the reviewer is that the reviewer served as a beta tester in the late stages of the product's development. We feel this review is unbiased and truly reflects the performance of the product in the simming environment. This disclaimer is posted here in order provide you with background information on the reviewer and connections that may exist between him/her and the contributing party.

© 2005 - Zane Gard and AVSIM Online
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