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Mission Statement 

The purpose of FLAPS-2-APPROACH is two-fold:  To document the construction of a Boeing 737 flight simulator, and to act as a platform to share aviation-related articles pertaining to the Boeing 737; thereby, providing a source of inspiration and reference to like-minded individuals.

I am not a professional journalist.  Writing for a cross section of readers from differing cultures and languages with varying degrees of technical ability, can at times be challenging. I hope there are not too many spelling and grammatical mistakes.


Note:   I have NO affiliation with ANY manufacturer or reseller.  All reviews and content are 'frank and fearless' - I tell it as I see it.  Do not complain if you do not like what you read.

I use the words 'modules & panels' and 'CDU & FMC' interchangeably.  The definition of the acronym 'OEM' is Original Equipment Manufacturer (aka real aicraft part).


All funds are used to offset the cost of server and website hosting (Thank You...)

No advertising on this website - EVER!


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If you see any errors or omissions, please contact me to correct the information. 

Journal Archive (Newest First)

Entries in Sim-A (3)


Primary Flight Display (PFD) - Differences Between Sim Avionics and ProSim737 Avionics Suites

As I work on a slightly more technical post, I thought I would post some images of the Primary Flight Display (PFD) belonging to two of the most popular avionics suites - ProSim737 and Sim Avionics.  I am not going to compare avionics suites in this post as both have their pros and cons and specific features.  What is important, is that the reliability and graphic output of either suite is second to none and exceeds that of many competing avionics suites.

Sim Avionics is owned by Flight Deck Solutions (FDS) in Canada and simulates both the B737 NG and the B777.  ProSim737, developed in the Netherlands, is dedicated solely to the B737 NG.

In the interests of disclosure, I own both suites, however, use ProSim737. 

A post located on the ProSim737 forum discusses the various PFD differences.  The post can be read here: 'Comparing the ProSim PFD' (thanks Jacob for sending this to me).

BELOW:  First image is a screengrab of the PFD from ProSim737.  Second image is a screengrab from Sim Avionics, while the third image is a photograph of a real B737-800 PFD.




Avionics Software - Selection and the Future

Southwest Airlines is the largest low cost airline in the United States, and has maintained its success on a simple business model - its decision to fly only one type of aircraft, the Boeing 737.  By streamlining their fleet to only one aircraft type, savings can be made in maintenance, logistics and support.

Southwest only need to employ maintenance personnel knowledgeable on one aircraft type, pilots do not need to be cross trained, and more importantly flight and support crews can be airlifted anywhere to begin work immediately should a problem arise.  There is no time delay waiting for a type pilot or engineer to be found.  In the airline business, lost flight time means a loss in revenue.

So what has this got to do with flight simulator or avionics software suites?

Avionics Software Suite – What’s this?

Before proceeding, the avionics suite is the software that controls the aircraft’s avionics systems within the simulator.  The avionics suite controls nearly everything associated with the simulator that is automated and includes among others: the integration of the Main Instrument Panel (MIP) and Main Control Panel (MCP) and the projection of this data to the Navigation Display (ND) and Pilots Flight Display (PFD).  The software does not replace the main flight simulator platform (FSX or whatever), but acts as a separate platform.

It’s important to realize that this software is VERY important.  It is the backbone of any simulation and directly controls whatever flight model you are using.  Any software used must be accurate, robust, replicate real aircraft systems, be reliable, and be able to replicate its outputs on a consistent basis.
There are two broad types of suites – those that can be used in a full flight deck simulation and those that are more suitable to a desktop set-up.

State of Play - Software Contenders

Historically, Project Magenta (PM) was only one contender if you wished to tackle the task of building a B737 simulation.   At the time, the software was complicated and required the user to network several computers.  The software developed by Project Magenta initially led the way, laying the building blocks for others to follow (bravo to PM).

In 2012, contenders are several: Project Magenta, Sim Avionics (Sim-A), Orion, Aerosoft Australia, Flight Deck Software, ProSim 737, Precision Manuals Development Team (PMDG), i-Fly and several lesser known companies produce software that emanates the avionics of the B737.  Other software suites “pop up” on the horizon from time to time as talented software engineers attempt to enter the marketplace.

Which Avionics Software Suite Should I Use?

This is a personal decision and I’m not going to publish a “tit for tat” discussion to which suite from which company is better or worse.  I will say that each company’s software brings different aspects of the flight deck to realisation – some with greater accuracy, detail and finesse than others.  Before you purchase a suite, it’s vital to investigate exactly what that suite can and cannot do in relation to the hardware you have installed in your simulator.

Software suites offered by rival companies are NOT identical to each other.  Some developers have added functions and displays to their software in an attempt to make them more user friendly, or to be used for multiple aircraft types.  Other developers try to maintain as much accuracy with the genuine B737 suite as possible.

Before purchase, you should identify what aspects are important to you, will work your simulator, and represent the functionality you expect.  Flight deck building and simulation is often very much about compromise.

Just because software is expensive or inexpensive, doesn't imply it's well tested and stable; try and see beneath the marketing veil.  Some of the smaller lesser known software suites are very good and provide excellent value for money.  For example, Aerosoft Australia has released a very competitively priced avionics suite which is more than enough for the average simmer who does not want to use an overhead panel.

Reliability, Repeatability, Accuracy, Expectations and Support

The most important facet of any software is reliability and repeatability; both mutually support each other.  Unfortunately, not all suites are reliable or have the ability to repeat defined outcomes.  Some high end and expensive software suites are plagued with teething problems, which for the most part, are left to customers to solve or report to the developer, in the hope that an update will rectify the issue.

As discussed earlier, software suites are not identical in functionality or appearance, even though in theory should mimic a real B737.  Although some of these variables are aesthetic, such as font type, size and colour; attributes that many virtual pilots deem important.  Other issues are not aesthetic and may relate to the available functionality of a particular system – such as the Flight Management Computer (FMC).  Depending upon the developer, upgrades to a software suite maybe frequent or only once every six months.

I have reviewed Sim Avionics in an earlier post.  ProSim 737 will be reviewed shortly.


It’s important to understand that replicating all the systems of a fully functional B737 is a continual challenge.  Real simulators can cost upwards of 15 million dollars and expecting the same level of performance, reliability and repeatability from a software suite, for less than $1500.00, is not reasonable.  Add to this the vast array of different computer designs and installed hardware and you can easily see why minor problems can occur.

EVERY software suite has teething and minor issues.  This said; please don't go away with the notion that every piece of software is a nest of problems - this would be incorrect.  What is important, is to go away with the notion of "reasonable expectation".

Some developers, in an attempt to work around complicated issues have chosen not to implement certain systems or parts thereof.  These same systems in another suite may work perfectly or not at all.  For the most part, problems stem in the accurate development and execution of Vertical Navigation and the integration of a “fully functional” Flight Management Computer (FMC).

Support from the development team of the suite you have chosen is paramount.  Many issues can and are easily solved.  But a prompt and efficient support base, regularly visited and updated by the software developers is essential.  It also should be noted, that many developers work closely with users to rectify teething issues within their software.   

Connectivity with Micro$soft Flight Simulator and Prepar3D

Most virtual pilots use FSX or the earlier FS9 as their baseline program.  These programs are no longer being developed or supported by Micro$oft and are quite ancient with regard to much of their software architecture.  Other than X-Plane and a few other “no shows” the only program being developed as a baseline program for flight simulator is the Lockheed Martin Prepar3D.  I am not using Prepar3D, however, I envisage I probably will be within two years.  It’s important to ensure compatible with what well may replace FSX.

The Future

What does the future hold?  As computers became faster and software advances continue, almost exponentially, I envisage that avionics software will become more sophisticated and refined in how fluid they interact with, and parallel real aircraft systems.  If the recent release of PMDG’s B737NGX is anything to go by, it’s only a matter of time.

Two Camps

Presently, there are two camps; desktop users and those using partially or fully developed flight decks.  This is not including turn-key type full LEVEL D simulators.

PMDG, closely followed by i-Fly have taken the limelight in the production and release of the NGX which is a truly monumental aircraft simulation more suitable for desktops than a flight deck.  I-Fly has been further developed with functionality to cater to flight deck builders.

Technology doesn't remain static and improvements will drive more companies to produce dedicated software; the days of one or two companies reigning is quickly paling.

Market Share

Historically, Project Magenta was the suite of choice for those wishing to develop a fully functional flight deck, however PM is no longer the “strawberry fox” and is now showing its age, being surpassed by new “high end’ contenders such as Sim Avionics and ProSim 737.  Put simply, these new contenders produce software that is more reliable and sturdier, easier to understand, install, and configure, and can operate on a minimal number of networked computers.

Project Magenta in an attempt to regain market share has also extended its reach to support different jet aircraft including general aircraft. Sim Avionics has followed suit; in addition to the 737-800NG, they also produce avionics suites for the B747, B767, B777 and the A320.

Southwest's Business Model

Other than i-Fly with its duel platform approach, and a few lesser known manufacturers, the only “high end” company dedicated ONLY to the development of the B737 for use in a full flight deck is ProSim 737.  Like Southwest Airlines, ProSim see benefit in producing only one avionics suite, doing it to the best of their ability and providing continued development until, if you excuse the phase “it’s as good as it gets”.

Leaders and Followers

The future is blurred, but in relation to a fully functioning B737 flight deck simulation, I believe that ProSim 737 and Sim Avionics will run “neck and neck”.  Presently, ProSim is more advanced in some aspects than Sim Avionics; but Sim Avionics comes under the mantle of Flight Deck Solutions which is a forward-moving company with a history of aggressive and progressive development.  I don't expect Sim Avionics will sit idle and wither on the vine...

Leadership in desktop simulation will probably be left to the current two major players PMDG and i-Fly; both which will “heckle” for the leadership, with i-Fly probably keeping feet in both camps.  

The other "lesser" contenders will always be there, and this is a good thing.  Competition drives development and improvement, which translates to increased functionality, greater simplicity and more stable software.  This can only benefit the consumer - YOU.



  • Please note that these are my opinions (albeit shared by other virtual pilots I am in contact with).
  • If you wish to comment, please you the comment form below.

Sim Avionics Flight Software - Review

I've heard it said that a "simulated flight deck is as good as the software behind the scenes" and I agree with this comment: a flight deck with poor software is a hive for frustration, disappointment and time wastage.

It's easy to write about the features and functionality of Sim-A as they are plentiful; but, I don't want to become too bogged down in minute detail, otherwise I’d be writing a manual.  This review will not address in detail everything that Sim Avionics (Sim-A) software can or cannot do; if your interested in a full functionality list, it’s best to check their website, as functions are altered and improved upon on a regular basis. 

Before continuing, it should be noted that there are several flight avionics suites currently available on the market.  They all replicate the basic avionics functionality of the B737.  However, not everything is operational with each suite and some functions behave differently between suites.  Therefore, it’s a good idea to research what works and what doesn’t before your purchase. 

Sim Avionics is a complete avionics solution providing the avionics software needed to build a fully functioning home cockpit; no other software is required.  It has been designed to run on multiple PC's in various configurations interfacing with FS2004 (FS9) or FSX via FSUIPC and Wide Client.

Relative Newcomer

Although a newcomer to Sim-A and still learning some of the more advanced features of the software, I thought it pertinent that I make an "introductory review".


Reliability is the most important aspect of any software.  To date, Sim-A has performed as one would expect from any high-end payware software. Overall, the software is reliable, performs well, and appears to be a robust and stable platform with consistent responses.

Certainly, it seems much more stable than some of the competitors on the market (if comments on flight simulation forums are anything to go by) and is far easier to use than some other well known brands.  But, it must be remembered that the software is only as good as the information inputted; therefore, if you try and do things that the aircraft & software is not designed to do, expect problems.

Further, you must bear in mind that no one computer (PC) is the same as another.  Different drivers, software, flight models and hardware configuration can cause any software to behave erratically from time to time.

This said, Sim-A can on occasion produce spurious results.  This is mainly associated with the more advanced auto pilot functionality and user operator errors!  

I’ve documented the issues and fixes, including some user operator errors, that troubled my installation below.

Issue 1 - Trim Tab Dancing

Now and again the trim tab will become unstable as the auto pilot continually recalculates the required pitch for the aircraft at the current speed.   The trim tab will “dance” causing the aircraft to pitch up and down. The trim dance (as I call it) occurs only on flights that have weather depicted, and it doesn’t occur on every flight.

FSUPIC to the Rescue

Although a little disconcerting, I believe the cause is not so much Sim-A, but the way the weather, especially aloft winds, are generated causing the elevator to continually move to counter weather differences.  There is a tab within FSUPIC that stops the elevator trim from operating when the aircraft is in auto pilot mode.  Since checking this FSUPIC setting (placing a tick in the box), the trim dance I was observing has decreased markedly and is now nonexistent.

Information for the auto pilot is located within the aircraft's configuration file.  If auto pilot trim issues persist then some minor tweaking of the numbers maybe required.  If this happens to you, then be rest assured that FDS and Sim-A staff will assist you with any minor tweaking to get you flying.

I’ve discovered that if the auto pilot does not provide consistent outputs (such as trim dancing), an easy method to often solve the issue is to switch the auto pilot command button off and then back on. 

Issue 2 - V-Nav Inconsistency

Replicating the more advanced B737 auto pilot functions requires complicated algorithms.  This is especially so with vertical navigation (V-Nav).  

Sim-A handles V-Nav reasonably well, although you have to keep an eye on what V-Nav is doing, espeially when transitioning from level flight to descent and approach.  On some flights, V-Nav honours the speed and altitude restrictions and transitioning the STAR to approach is accurate.  However, at other times restrictions are not followed and the aircraft will overshoot the height and speed restriction.

V-Nav always operates correctly on take-off utilizing a Standard Instrument Departure (SID).

There is no particular reason for this - it just happens from time to time.

Understanding V-Nav and what its doing can be challenging

The challenge, I have discovered when using V-Nav is two-fold.  First and foremost, you must use it within the designed capabilities of the program, and second, you must learn how and when to operate V-Nav.  If you enter data that the FMS cannot assimilate, such as an altitude that is too high or too low, for the time required to reach the waypoint, then expect an overfly of the entered restrictions.  This is not the fault of Sim-A.  It's user error

Sim-A, in my opinion is not alone with minor V-Nav issues; Project Magenta, Pro Sim 737 and others also have difficulties replicating this complicated algorithm. Indeed, real pilots are often confused understanding how V Nav operates and why it's doing whatever it's doing! 

This is one reason why V-Nav should only be used as a guide and not as an absolute.  If V-Nav, for whatever reason does not function in a method you believe to be correct, then turn it off and use the more reliable L-Nav, Level Change or Vertical Speed functions.

Issue 3 - Display Lag and Staggering

There is minimal display lag running Sim-A and FSX (using two computers). 

The gauge movement of the displays is fluid and there is no pausing as information is shuttled to and from the computer and Sim-A.  However, if “all waypoints” is selected to be displayed on the ND, then staggering becomes obvious on the Main Flight Display’s altitude tape, as the aircraft ascends or descends in altitude. 

I’ve been told by long-term Sim-A users that this is normal as the information required to display and update the “all waypoints” is very comprehensive and can easily generate an “information bottleneck”.  The solution is easy – turn off “all waypoints” when climbing, descending, or on approach.  Honestly, I rarely have "all waypoints" selected and only use this function if I am searching for the nearest waypoint to make an alteration to the flight plan.

I have not experienced any display lag or staggering issues with other EFIS functions. 

Issue 4 - Software Server.exe Lock-up

When you read this title, I can image the thoughts going through your mind.  But, this is one of those negative aspects that has a very positive twist. 

Although the software has never crashed to desktop, it has on occasion “locked up” requiring a reboot of the Sim-A server.exe.  The lock up usually occurs when I have been repeatedly doing something incorrectly, such as keying into the CDU  incorrect information, therefore; the lock-up caused by user error

If this issue should occur (for whatever reason), it's only a matter of closing the server.exe using the shutdown command tab and then reopening the server.exe window.  You do not need to close down Sim-A or FSX. 

This brings me to the positive twist I mentioned in the earlier paragraph.

Outstanding Sim-A Feature

Of the many features Sim-A has, the ability to historically re-set the software without loosing your flight details or actual flight (in real time) is probably one of the more beneficial. 

If a problem should transpire during a flight causing the server.exe display to freeze or something to stop working, you can re-set the software by closing the server.exe display and reopening it.  The interruption to your flight will be seamless, providing you depress the tab “last state” within ten seconds of reopening the server.exe display window.

This is but one of several "smart" features that are often overlooked.

Functionality Controlled by Control Panel

Sim-A’s central access point is the control window (server.exe) which is always visible on your “flight configuration” monitor. 

The server.exe display window is the core of the program and shows the current “avionics” status of your aircraft (EFIS settings, weather, terrain, TCAS settings, aircraft details, engine, hardware settings, etc).  The display also provides a handy central area in which you can tweak the aircraft’s .cfg file, FSUPIC settings, offsets and so forth.   For more detail on this comprehensive display I direct you to the Sim-A website.

LEFT:  This is screenshot of the main Sim-A interface (server.exe / control window).  From this screen you can control all of the Sim Avionics variables.  It does look complicated and there is a lot of information on the screen; however, it took me less than 30 minutes to get a rough idea what was happening and get into the air.  Menu tabs open up further screens and all settings are automatically saved on a regular basis. 


Sim Avionics Features

At the minimum Sim-A will supply you with:

  • Captain and First Officer Pilot Flight Display (PFD) and Navigation Display (ND)
  • EICAS Display (upper & lower) with fully integrated EICAS messaging
  • Virtual Main Control Panel (MCP)
  • Virtual EFIS Display (two)
  • Virtual overhead panel
  • Virtual CDU Display
  • Multiple CDU Support
  • Support for Hardware MCP & EFIS
  • Complex Auto Pilot Functionality (SINGLE CH, LAND 3)
  • Sound module
  • EGPWS and TCAS
  • B737 system logic
  • Radar (weather) & Terrain overlay displays
  • Virtual stand-by instruments (vast selection)
  • Fuel & scenario loading platform (dispatcher console)

Other functionality, such as instructor station, and observer CDU is available depending upon which license type you purchase.

To see screen grabs of the display functionality of Sim-A (PFD, ND, radar, etc), navigate to the PFD page on the Sim-A website

Of course, if you are operating a full flight deck with the appropriately supported hardware you will not require the virtual MCP, EFIS, CDU and overhead displays.

Support for Add On Hardware, Flight Models & Software Cloning

Speaking of hardware, SIM-A supports many of the popular hardwired instruments available on the market.  For instance, the CP Flight MCP and EFIS units are, with some minor .cfg  file alterations plug & fly.  Similarly, GoFlight and Flight Illusion products are easily configured for Sim-A use.

Currently SIM-A supports the B737 and the B777.  Several B737 and B777 aircraft configuration files (FS9 & FSX versions) are available within the software: default model, PMDG, Posky, Wilco, XPlane and Meljet.

Another feature of Sim-A is the ability to run certain aspects of the software from different computers.  For example, you can clone the sound module to run on different computers, thereby, playing aircraft sounds through one set of speakers, and ATC commands through another set of speakers (or headset).

CDU - Background Software

No review of Sim Avionics would be complete without a short segment on the CDU.

Sim-A is the controlling software that provides the intelligence behind the CDU.  It's amazing what this software can do, and do so with reliability and consistent behaviour. 

Most pages associated with a commercial CDU are modeled and updates continue to add new features and improve on existing functions.  Some of the basic features that are modeled by the software are:

  • Indent page on start-up (weights, fuel, cost index, etc)
  • Approach reference page with VREF selection
  • Route, LEGS, Arrival, Departures & Holding pages (user controlled including approaches, STARS & transitions)
  • Progress pages (fuel, distance to go, ETA, wind, crosswind component, cross track error, fuel prediction etc)
  • Cabin calls
  • METAR (real time)
  • V-Nav & L-Nav compliant (climb, cruise and descent)
  • GPWS overrides
  • NAV radio page (ADF, VOR & ILS data)
  • Captain EFIS control
  • SIM control page (separate commands to control SIM instead of using keyboard)

To see screen grabs showing the various features available, navigate to the CDU page on the Sim-A website

Further Functionality

I/O Interfacing and FSUPIC is fully supported as are FSUPIC offsets, and if your using an FDS MIP, a program called InterfaceIT provides an interface for connection of switches, lights and other modules to Sim-A. 


A manual is supplied with the software and there are several documents (within the documentation section of the main Sim Avionics folder) that assist in the correct set up procedure. It is VITAL that you read all the documentation BEFORE installation. 

To read the Sim-A installation & operations manual, navigate to the Training Section.

For a more in-depth look at how the autopilot functions, see this document in the Training Section Autopilot Functional Examples - Sim Avionics.  This document provides an excellent review of MCP procedures in relation to take off, descent and landing (ILS & LAND 3).

Software Installation

Installation is uncomplicated.  However, there are a number of changes you need to make to several files to ensure correct operation.   Additionally, if you’re using two computers then basic networking knowledge is required, as are the programs Wide Client FS and a registered copy of FSUPIC.

Determining the correct location for the various avionics displays on the computer monitors (within the MIP) is straightforward, although fine-tuning the location on the monitor can take a little time.  Basically, you alter the length and width of the various displays within the config files.  Once you know how this is done, it's just a matter of altering the line numbers until your satisfied with the result.

When Sim-A is set-up correctly, everything is relatively painless and obvious - more or less “following your nose”.

Running a flight deck isn’t pressing a button and “presto” there it is… 

For the avionics suite to operate correctly, several programs or clones of the program must be loaded.  At the minimum this is: Captain's PFD and ND, First Officer's PFD and ND, CDU, EICAS, Server.exe, Tcp Client, InterfaceIT, Wide FS and Sound.  Depending upon your requirements and set-up, the MCP, Overhead, First Officer's CDU and the Dispatcher console may also need loading.  The window displays are opened by clicking the .exe shortcut files that the program installed to your desktop.

To minimise the time in loading and to be user friendly, a handy program has been included with Sim-A, hidden within the documentation folder; it is a start-up batch file. This program allows to you start all the functions and displays with the click of one button.

I've compiled a short video showing how the program automatically opens and loads the software using the batch file.  In my set-up, Sim-A is installed and operates from my second computer (client). 

Double click to open and close full screen viewing.

Video showing operation of batch file.

Video showing the various functionality available via the main display server.exe window.

Ownership and Support

Sim Avionics is the preferred avionics suite of Flight Deck Solutions.  If you purchase an integrated MIP from FDS, Sim-A is the flight software that will be supplied. 

Support for Sim-A is provided by the software’s main engineer and FDS staff.  Help can be obtained either via the active support forum (on the FDS website) or via e-mail.

Continual Development & Financial Investment

Sim Avionics is not an inexpensive investment, however, it’s pleasing to see continued development of the software; updates that add or improve on existing functionality are released on a regular basis.  Furthermore, the software designer is open to suggestions from users on how to enhance the software.

At the time of writing, if you purchase Sim Avionics through Flight Deck Solutions then the price of the software includes full support and updates for an unlimited time period. 

Recommendation & Overall Score

Sim Avionics is a stable, well tested and tried software platform that provides most of the real-world avionics of a B737 jet-liner.  The software is easy to install and use, however, advanced knowledge is required to use some of the advanced features such as FSUPIC offsets and the like.  All avionics software has issues from time to time, and Sim-A is no different, but the ongoing development of this software and a solid support structure can only be seen as positive.

To investigate Sim Avionics more closely, visit their website - Sim Avionics Website.

My Rating is 8.9/10

Please note that this review is my opinion only and is not endorsed.