E-mail Subscription

Enter your email address:

Delivered by FeedBurner

Syndicate RSS

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!


Find more about Weather in Hobart, AU
Click for weather forecast






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

Journal Archive (Newest First)

Entries in Flight Simulation (21)


Integrated Approach Navigation (IAN) - Review and Procedures

Increased navigational accuracy obtained from software and hardware improvements have led to several enhanced approach types being developed for the Boeing 737.  These augmented approach types provide a constant rate of descent, following an approximate 3 degree glide path, and eliminate the traditional step-down style of approach.  The benefits being a  stabilized and safer approach, greater passenger comfort, less engine wear, tear and fuel usage, and a lower workload for the flight crew.

LEFT:  Nippon Airways (ANA), one of Japan’s premier airlines uses Integrated Approach Navigation (IAN) on many of its routes.  Utilizing IAN can produce considerable savings to an airline by minimizing engine wear, fuel costs, and standardizing flight training.  Click image to enlarge.

In this post, I will discuss the concept of Integrated Approach Navigation (IAN) and explain the procedures recommended by Boeing to successfully implement IAN. 

I have attempted to cover all the detail concerning IAN in one article, however, when a lot of detail is discussed it can, on occasion, lead to confusion.  Therefore, I recommend you read the Boeing Flight Crew Training Manual for more in-depth information.

The Navigation Performance Scales (NPS) which augment IAN will not be discussed.  NPS will form part of a future topic.


Integrated Approach Navigation (IAN) provides a display similar to the Instrument Landing System (ILS) and allows the flight crew to fly any published approach that exhibits a glide path within the navigational database of the Flight Management System (FMS).  Flight path guidance is derived from the Central Control Unit (CDU), navigational radios (NAV1/2 & ADF 1/2), or combination of both.  For IAN to engage correctly, an appropriate approach (an approach with glide path) must be selected from the CDU database.

IAN is an airline option, and not every airline carrier will have IAN as part of their avionics suite.  However, the technology is becoming more popular as the safety and economic benefits of IAN are understood by airline carriers.

Geometric Path

The geometric path used by IAN approximates a 3 degree glide path; nevertheless, this glide path may not comply with the CDU designated altitude constraints prior to the Final Approach Fix (FAF).  This said, the generated glide path will always be at or above the altitude constraints between the FAF and the Missed Approach Point (MAP) published in the CDU approach procedure.

Critically, IAN is a Category I Non Precision Approach (NPA) and is not to be confused with an ILS precision approach.  Therefore, NPA procedures must be adhered to when initiating an approach using IAN.  

Although the automation provided by IAN will guide an aircraft (in most cases) to the threshold of the runway, IAN has not been designed to do this.  Rather, IAN has been designed to guide the aircraft to the Missed Approach Point (MAP) published on the approach chart.  The flight crew will then disengage IAN by disengaging the autopilot and autothrottle and fly the remainder of the approach manually as per NPA protocols.

In some instances, the final approach course (FAC) is offset from the runway centreline and manoeuvring the aircraft for direct alignment will be necessary, whilst following the glide path (G/P) angle.

Although the final approach is very similar to an ILS approach, IAN does not support autoland; therefore, if the aircraft is not in a stable configuration and the crew not visual with the runway at or beyond the MDA, a missed approach procedure will need to be executed

Ground Proximity Warning System (GWPS) Aural Warnings and Displays

GWPS warnings will annunciate if at any time the aircraft deviates below the glide path, and failure of a crew to disengage IAN at the appropriate altitude will trigger an GPWS aural warning alert ‘autopilot autopilot’ at 100 feet radio altitude.  This is in addition to the words ‘autopilot’ being flashed on the Primary Flight Display (PFD).

Benefits of Using IAN

There are multiple benefits to an airline using IAN, the foremost being flight safety. Unstable approaches contribute to many aircraft accidents, and flight crews strive to always establish a stabilised approach profile for all instrument and visual approaches.  

The Global Position System has enabled stabilized approaches at many airports and advanced features such as IAN take advantage of this technology to provide consistent, intuitive displays that support stabilized approaches. 

18 Approaches Types to 1

Through the use of IAN, the number of approach types has been reduced from 18 to 1, greatly simplifying the approach procedure and minimizing the amount of time an airline needs to train pilots in numerous approach types.  Time is money and utilizing advanced technology such as IAN can increase airline productivity.

Additional Data - Increased Awareness

The distance to runway threshold, approach guidance information, and vertical and lateral deviation markers are displayed when IAN is in range of a designated runway.  Whether IAN is used or not, this information provides additional guidance when executing an approach. 

For example, when executing a VOR approach, this information has been displayed on the Navigation Display (ND) as the distance to the actual NAVAID (VOR) - which may or may not be aligned with the threshold of the runway.  IAN will by default, display the lateral and vertical deviation, and distance to the runway threshold, allowing for greater precision during a non-automated approach.

These are but a few of the advantages to using the Integrated Approach Navigation system.

Using IAN - General

The following information provides guidance in the general use of IAN.

IAN can be used for the following approach types: RNAV, VOR approach, GPS, NDB approach, LOC, LOC-BC or similar style approaches. If using IAN to execute a Back Course Localizer approach (B/C LOC), the inbound front course must be set in the MCP course window (either Captain/First Officer side, or both depending on CDU set-up).

LEFT: IAN approach to VOR/DME RWY 24.  FAC is engaged while G/P is armed. The lateral and vertical deviation pointers are displayed and will, change colour to solid magenta when the G/P engages.  A benefit if using IAN is that it provides an accurate distance from the threshold to the aircraft - in this case 9.7 miles. (ProSim737 avionics suite).

Although the use of IAN is recommended only for straight-in approaches, field use suggests that flight crews routinely engage IAN when no more than 45 degrees from the runway approach course.  During the approach the crew must monitor raw data and cross check against other navigational cues.  

IAN does not need to be specifically ‘turned on’ for it to function; the functionality, if installed in the aircraft is always functional.  When the aircraft is within range of the designated approach, the runway data will annunciate on the PFD. At any time after this point has been reached, IAN can be armed/engaged by pressing the APP button on the MCP.

LEFT: An example (not related to PFD image) showing a typical CDU generated approach which is IAN compliant.  The altitude (3000 feet) positioned above the entry GP3.00 is the altitude set to the MCP altitude window.  An approach may have several glide path entries; always select the first entry.  CDU is manufactured by Flight Deck Solutions (FDS).  Click image to enlarge.

Navigation Radios

An IAN approach can be executed without the guidance from navigation radios; however, this is not recommended as correct tuning of the radios can provide increased visual awareness and redundancy should a failure occur with the CDU, or the dataset becomes corrupted. 

LEFT: Montage of four PFDs showing various annunciations and displays for the IAN system.  Sequence is top left to right and bottom left to right. Click image to enlarge (ProSim737 avionics suite).

Boeing strongly advise to tune the radios to the correct frequency for the approach, to eliminate the possibility of the radio picking another approach from a nearby airport and providing erroneous data to the crew.  If using IAN for an ILS approach (glide slope inoperative) the radio must not be tuned to the ILS frequency.

Minimum Descent Altitude (MDA)

As discussed earlier, an IAN approach is a NPA and when authorized by the Regulatory Authority, non-ILS approaches can be flown to a published VNAV Decision Altitude/Height (DA/H) or to a published MDA (the MDA is used as a decision altitude).  If not authorized to use the MDA as a decision altitude, crews must use the MDA specified for the approach flown.

To comply with the MDA protocols during a constant angle approach where a level off is not planned at the MDA, it is necessary to add +50 feet to the published MDA.  If a go-around is required, this allows an adequate buffer to prevent incursion below the MDA.

Using IAN - Understanding IAN Displays

IAN generates several visual displays which inform the flight crew of the status of the system.  These displays, which are triggered at various operational phases, are visible on the attitude display of the PFD and on the Flight Mode Annunciator (FMA).

Approach Guidance: The PFD will display the method of initial approach guidance in white whenever IAN is active.  The display will differ and is dependent on the approach type selected.  For example, LNAV/VNAV, FMC, LOC or ILS, depending on the source of the navigation guidance used for the approach (navigation, radio or CDU approach data).  An IAN approach will display FMC.

Approach guidance is activated when a crew selects TO/GA during the take-off roll, or when the aircraft is within range for the system to be armed/engaged.

Runway Data:  Whenever IAN is within range of a selected approach, the PFD will display the runway data (type and name of approach, runway designator and distance to threshold).  The display of the runway data is the crew’s first ‘notification’ that the IAN functionality is able to be used.

Final Approach Course (FAC):  FAC is displayed on the center FMA when the APP button on the MCP is pressed, and IAN is in range of the approach selected.

Glide Path (G/P):  G/P is displayed in the right FMA to indicate that the aircraft has a associated glide path to follow.

Two FMA colours are used.  White indicates that FAC or G/P is armed.  Once the aircraft is closer to the Final Approach Point, the FAC annunciation will change colour from white to green.  Green indicates that the final approach course is active.  Likewise, when G/P changes colour to green, it indicates that the aircraft has a dedicated glide path to follow.

It stands to reason, that FAC is usually annunciated prior to G/P, but depending upon the position of the aircraft when APP in pressed on the MCP, both annunciations may annunciate singly or together, in white or in green.

Lateral and Vertical Guidance Deviation Markers:  These are the magenta coloured diamonds, familiar to ILS approaches.  The diamonds provide the lateral position of the aircraft relative to the designated runway course and the vertical position relative to the glide path.  The diamonds are initially displayed in outlined magenta followed by solid magenta when the aircraft captures the glide path.

SINGLE CH:  SINGLE CH will be displayed in green, when the aircraft captures the glide path. At this time, the deviation markers will change from outline to solid magenta.  FAC and G/P on the FMA will also change from white to green.  At this point the aircraft will be guided automatically along the glide path.

Using IAN - Proceedure

  • IAN is engaged only after clearance for final approach has been received from Air Traffic Control (ATC).  By this time, the aircraft is probably on a straight in approach.  IAN is not designed to navigate to the airport.
  • IAN cannot be used for STARS and is not designed to be engaged when the aircraft is miles from the designated runway.  Flight crews transition to an IAN approach from any of several roll modes (VNAV/LNAV, Level Change, V/S or manual-controlled flight).
  • To arm/engage IAN, the flight crew press the APP button on the Mode Control Panel (MCP) similar to performing an ILS approach.

The APP mode is only to be selected when:

  • The guidance to be used for the final approach is tuned and identified on the navigation radio;
  • An appropriate approach has been selected from the CDU database which has a glide path attached to it;
  • The appropriate runway heading is set on the MCP course window;
  • The aircraft is on an inbound intercept heading;
  • ATC clearance for the approach has been received; and,
  • Both lateral and vertical deviation pointers are visible on the attitude display in the PFD.

IMPORTANT NOTE:  It is possible to select APP prior to the display of the deviation pointers, however IAN will be in armed mode.  IAN will only engage following aircraft capture of either the lateral or vertical flight path (FAC & G/P).  IAN can be armed whenever the aircraft is in range of the airport - in other words whenever the runway data is displayed on the PFD.

Many flight crews engage IAN only after the deviation pointers are visible (this follows the similar ILS approach method).

Using IAN - Set-Up

  • Select the appropriate approach to use from the CDU database.  Ensure that the selected approach has a glide path.  Do not alter any of the approach constraints.  Set the glide path altitude to the MCP altitude window.
  • Fly the aircraft in whatever roll mode to the Initial Approach Fix (IAF).  Remember straight-in approaches are recommended – a 45 degree offset to the approach course is also suitable (varies).  Do not engage IAN until the aircraft is in the correct position relative to the approach course.  IAN will usually become active – the approach guidance will be displayed on the PFD – at around 20 miles from the runway threshold.
  • Configure the navigation radios to the correct frequency for the designated approach.  Do not use an ILS frequency.
  • Set the barometric minimums to the altitude published on the approach chart.  Add 50 feet to avoid breaking NPA protocols.
  • Set the correct runway approach course to the MCP course window.
  • When the runway data is displayed on the PFD, IAN is in range.  At this point, the APP button on the MCP is pressed to arm IAN (this action can be delayed if not on straight-in approach heading).  The FMA will annunciate FAC and G/P in white to indicate the IAN system is armed.
  • When the aircraft is alligned with the lateral and vertical profile, the colour of the FAC and G/P annunciations will change from white (armed) to green (engaged).  The lateral and vertical deviation markers will also annunciate with a magenta outline.
  • As the aircraft closes on the runway threshold, and when the glide path has been reached, the deviation markers will become solid magenta and SINGLE CH will annunciate on the PFD.  The FAC and G/P annuniations on the FMA display will now be green.  The aircraft will begin to descend along the glide path.
  • Once the aircraft has descended, at least 300 feet below the altitude previously set in the MCP altitude window; the missed approach altitude (MAA) can be set on the MCP.  This figure is published on the approach chart.  Failure to wait until the aircraft descends 300 feet will cause the ALT HOLD annunciation to display and the aircraft levelling off.

Using IAN - Pilot Procedures

The procedures used for an IAN approach are derived from current ILS procedures and are consistent for all approach types.  This is the procedure after IAN has engaged.

  • When 2 miles from the Final Approach Fix (FAF) - GEAR DOWN, FLAPS 15, SPEED CHECK.
  • At glide path capture – FLAPS 25/30 (landing flaps), SPEED CHECK.
  • At 300 Feet below glide path capture, reset the MCP altitude window to the missed approach altitude.
  • At minima – Disengage autopilot and autothrottle, manually align aircraft and follow vertical deviation markers and Flight Director (FD) cues to runway threshold.  Maintain the glide path to the flare and do not descend below the visual glide path.  Although glide path guidance can be used as a reference once the aircraft descends below the MDA, the primary means of approach guidance is visual.  If not visual at MDA, execute a go-around.  Remember using IAN is a Non Precision Approach (NPA).

IMPORTANT NOTE:  The transition from roll mode to IAN approach can be quite sudden and a flight crew must be vigilant and anticipate actions and events before they occur.  If the aircraft is travelling too fast, slowing down after IAN has engaged can be difficult. 

Likewise, if the aircraft is too high and IAN engages, the vertical descent can be steep as the aircraft attemptes to follow the IAN generated glide path.

Therefore, maintaining the correct approach speed and altitude is paramount to a successful IAN approach.  If using VNAV, it often is good idea to engage SPD INTV to manually control MCP speed.

Flight crews often transition to IAN from whatever automation mode they are using at the Initial Approach Fix (IAF), or they manually follow the deviation pointers generated by IAN until confident that the aircraft will not behave erratically when IAN is engaged by pressing the APP button on the MCP.

FIGURE 1:  Visual representation of an IAN approach and transition from roll mode.  Copyright Boeing FCTM, 2014.

On another note, when an IAN approach mode is selected, the APP mode in the EFIS can be selected to display the approach (as in an ILS approach in the Navigation Display).

Using IAN - Situations To Be Mindful Of

Automation can have its pitfalls, and IAN is no different.  However, once potential shortcomings are known, it is straightforward to bypass them.  The most common mistake, especially with virtual pilots, is not following the correct procedure.

Possible 'surprises' associated with IAN are:

1:  Failing to configure the aircraft prior to IAN engaging in FAC and G/P mode.

Unlike an ILS approach, where configuration for landing is initiated when the glide slope comes alive (solid magenta deviation markers), during an IAN approach, configuration for landing is initiated approximately 2 miles from the Final Approach Fix (FAF).  

The reason for this, as discussed in the overview section, is that IAN creates a glide path from the designated runway threshold to the position of the aircraft.

If the crew wait until the IAN glide path becomes alive (solid magenta deviation pointers), there may be insufficient time for the crew to complete recommended actions and checklists before intercepting the glide path. 

2:  Forgetting to set the Missed Approach Altitude (MAA) in the MCP.

Failing to wait until the aircraft has descended 300 feet below the glide path capture altitude to reset the MCP altitude to the MAA.  Failure will cause the aircraft to revert to ALT HOLD.

3:  Approaching the runway not on the correct intercept course

IAN operates flawlessly with straight-in approaches and to a certain extent with approaches roughly 45 degrees from the main approach course.  IAN will not engage if you approach the assigned runway at 90 degrees.  Nor will IAN engage if you are attempting to fly a STAR.

4:  Transition from roll mode to the IAN approach can be abrupt with loss of some visual data

The PFD will display differing annunciations depending on the type of approach configured from the CDU database, and the roll mode being flown prior to IAN engaging. When IAN is in range, some of this displayed data will be replaced with data from the IAN system.

For example, if the primary navigation is using VOR/LOC, and when IAN comes into range, the approach guidance, runway data and deviation markers will be displayed in the PFD.  However, simultaneously, the Navigation Display (ND) will display EFIS MODE/NAV FREQ DISAGREE.  If executing a VOR approach, and not wanting to use IAN, loosing the VOR directional marker in the ND, if unexpected, can be disconcerting. 

Note that this will occur whenever IAN is in range of the designated runway (IAN does not necessarily have to be armed or engaged)  But, be assured that the VOR/LOC is still being followed, despite the VOR directional marker not being able to be viewed in the ND.  The FMA will indicate what the aircraft is doing - in this case the FMA will display VOR/LOC (always y look at the FMA to determine what level of automation the aircraft is using). 

5:  Forgetting to set the altitude in the MCP (from the CDU glide path)

A common mistake is to not set the altitude in the MCP altitude window to the altitude that is associated with the glide path for the desired approach.

ProSim737 and IAN

Integrated Approach Navigation has only recently been introduced to the ProSim 737 avionics suite (late December 2014).  As such, there are ‘teething issues’ associated with its use.  With time, it is envisaged that the developers of ProSim737 will rectify shortfalls to ensure accurate and trouble free operation.

Five known shortfalls at the time of writing are:

(i)     ProSim737 does not display the IAN runway data immediately following the engagement of TO/GA during the take-off roll.  This is incorrect.  In the real aircraft, this information is displayed immediately following the engagement of TO/GA during the take-off roll while the aircraft is on the ground.

(ii)     The colour of the approach guidance display (LNAV/VNAV) after TO/GA is engaged is currently white.  This is incorrect.  The colour should be green (further research required, F2A).

(iii)     The runway data and approach guidance displays are not identical to the real aircraft – they are the incorrect font size.  This is a minor issue.

(iv)     Interestingly, ProSim737 allows an IAN approach to dunction with any CDU generated approach procedure (with or without glide path).  This is incorrect.  An IAN approach can only be generated with an approach that displays a glide path.  Although the reason for this is uncertain, I am lead to understand that it is associated with the navigational database, which is beyond the scope of ProSim737 (course is an outside source).

(v)     Once IAN is armed/engaged and an approach selected from the FMC database via the CDU, the ability to fly a standard VOR approach ceases.  The message EFIS MODE NAV FREQ DISAGREE will be displayed on the Navigation Display when VOR is selected on the EFIS.  The only way to fly a VOR approach is to not select a VOR approach from the FMC database.  This is not correct.  IAN should not take control of a VOR approach.

ProSim737 users should also note, that for IAN to function within the avionics suite, it must be activated in the cockpit set-up page of the instructor station (IOS).

Final Call

Aircraft fitted with IAN, are capable of using the APP button located on the MCP, to execute an instrument ILS-style approach based on flight path guidance from the CDU.  This makes Non Precision Approaches easier to execute with increased safety.  It also enables a constant descent angle, less engine spooling, wear and tear, and improved passenger comfort.  Furthermore, IAN utilises a standardised procedure and as such, when installed, is usually used in place of LNAV and VNAV due to its straightforward method of use.

Nevertheless, a flight crew must be vigilant when using any automation, especially during the critical approach phase where there is little margin for error.  First and foremost is the innate ability to fly the airliner manually, and although automation such as IAN can enhance safety, it does so at the detriment of manual flying skills.


Several sources were used to obtain the information documented in this post, including: personal communication with a B737-800 pilot, the Boeing Flight Crew Training Manual, 2014 and the Boeing 737 Technical Guide by Chris Brady.

If any discrepancies are noted in this article, please contact me so they can be rectified.

Acronyms and Glossary

APP – Approach button located on MCP
CDU – Control display Unit (aka Flight Management Computer – FMC - I use CDU and FMC interchangeably)
FAC – Final Approach Course
FAF – Final Approach Fix
FMA – Flight Mode Annunciators
FMS – Flight Management System
G/P – Glide Path (non precision approach)
G/S – Glide Slope (precision approach)
IAF – Initial Approach Fix
IAN – Integrated Approach Navigation
ILS – Instrument Landing System
MAP – Missed Approach Point
MCP – Mode Control Panel
MDA - Minimum Descent Altitude
PFD – Primary Flight Display
STAR - Standard Terminal Arrival Route

  • Reviewed and updated 25 August 2017.

SISMO Soluciones - Avionics Review: My Negative Experience 

 I initially wasn't going to document my negative experience with Sismo Soluciones as many simmers use SISMO products and are fiercely loyal to this company.  This post has sat unpublished for close to 10 months until a friend convinced me otherwise, saying that bad reviews can be beneficial, especially to new simmers who are undecided on what and whom to purchase from.

This is the first negative review I have written and in doing so realize that I will no doubt annoy some people, especially loyal SISMO customers.  My aim is not to annoy, intimidate or create malicious rumours.  Rather, it is to share with others my experience with this company. Due to the negative nature of this review, it WILL NOT be posted to any forum.

I purchased the following units from SISMO:

  • ADF radios (2)
  • Transponder / ATC radio
  • Audio Control Panel 
  • rudder trim module

At the time, I was using Sim Avionics as my avionics suite.

I had issues with: aesthetics, quality assurance and the SC Pascal script usage.  

When you initially look at the modules offered by SISMO, they do look attractive; however, it's often the small things that count and SISMO, in many respects, lacks quality and attention to detail.

  • This post is a little different.  I've made a basic review of the modules, then discussed the issues I had with the panels/modules and the company.

Overall Module Construction and Appearance

The modules are constructed from acrylic and painted in Boeing grey.  CNC machining produces a crisp finish resulting in lettering cut-outs that are well defined allowing back lighting to illuminate the lettering.  Buttons and switches are machine injection moulded and secured to rotary stems via two small grub screws. The electronics are not sealed within the unit (such as in CP Flight) but are visible.  DZUS fasteners are not included although holes have been drilled in the appropriate position (although these holes are too small to fit genuine DZUS fasteners).  The backing plate is made from plastic.

Paint Work

The paint work used by SISMO is not of a high quality.  The paint wears thin on the panel beneath the knobs and switches after minimal use.  The paint also chips very easily and is not evenly applied to include the side of the unit.  Although I don’t know how many layers of paint have been used, I’d suggest it’s minimal.  Minimal paint saves time and expense and does not lend itself to high quality and longevity.

Integrated Back-Lighting (IBL)

SISMO does not utilise real aircraft bulbs for backlighting.  Rather they use a number of strategically placed LED lights.

LEFT:  SISMO ADF unit & FDS NAV1 unit.  Note the difference in backlighting and module colour between the two units.  FDS use real aircraft bulbs. 

There are several arguments for and against the use of bulbs and LEDs.  The former provide a realistic throw of light at the correct colour temperature, while LED’s are usually more pin point, require less power to run and usually appear colder in colour temperature.

The Backlighting on the SISMO modules is reasonable; however there is not an even throw of light across the rear of the modules to allow complete illumination of all cut out lettering, nor does a light skirt inhibit stray light from illuminating the outer edge of the modules  The backlighting is powered by 12 volts.  The colour of the LEDS is amber yellow or warm orange.

I had an issue with two LED lights; The LED lights stopped working.  SISMO informed me I would have to repair this myself.  Shortly thereafter, a third LED light failed. This suggests that SISMO may have a quality issue in relation to LEDS (at least in the batch I received).


The upper panel of the module is attached to the electronic circuitry within the lower section by a backing plate.  This backing plate is made from plastic.  It should be constructed from metal to aid in strength.  The electronics “appears” substantial and to be well built.  

System and I/O Cards

The modules are not stand-alone devices.  Depending upon your requirements, the modules require connection to various system and sim cards for complete operation.  As an example, to operate the ADF units and rudder trim module requires three GIC connection cards, an Ethernet motherboard card, and three servo-daughter cards – seven cards in total!  

Although there is nothing wrong with this method of operation, it does pose a challenge to find a suitable location to mount the cards.  The cards appear to be constructed to a high standard and are very solid; they do not feel or look like cheap Chinese cards.

The main Ethernet mother board requires a 5 volt power supply.

I’ve included, for interest, a schematic wiring and card diagram of the module set-up for the Captain-side ADF radio. (click the image to enlarge the picture). 


SISMO provides you the opportunity to either use their prefabricated flat wiring or to wire everything yourself.  I choose the former and this saved a lot of time and frustration wiring and soldering.  The flat wiring packs are each fitted with heavy duty plastic clips for attachment to the cards.  Connection is straightforward and SISMO provide large A3 colour wiring sheets so you know exactly what wire plugs into what card.

When you do utilise the flat wiring, it’s necessary to include in your system a number of additional cards that act as joiners between the different system cards and modules. These cards are called Generic Interface Cards (GIC), and are little larger than a credit card in size. 

Too Many Cards

The amount of wiring and number of cards needed to use SISMO products is ridiculous!  With four modules connected, the interior of the center pedestal is a mass of wires leading to and from various interface cards.  There are far better and easier alternatives available from other manufactures.  

LEFT:  SISMO modules, power and flat cabling.  There is a lot of cabling and several required interface cards that are required.

The Power of Ethernet

SISMO’s product range utilises Ethernet technology rather than USB.  According to SISMO literature, USB was not designed to carry the volume of information necessary for flight simulation.  Although USB is practicable and does work very well, it can on occasion malfunction (drop out) or slow the operation of the intended device by creating a bottleneck for information flow.  Ethernet, on the other hand, has been designed at the onset to allow for high information flows ensuring fast and consistent transfer of information.

Another benefit of Ethernet is that it doesn’t matter if the computer that your modules are connected to is not a high-end machine, as the speed of Ethernet flow far outweighs the need for a high-end machine as a client PC. 

An Ethernet cable is required to link the main Ethernet mother board, either directly to the computer or to a switch if using two or more networked computers.

Although the theory is sound, speed wise I don’t believe there is a great difference between using Ethernet or USB for the transmitted information loads (at least for the center pedestal).

Real B737 Center Pedestal - Not Drop & Fly

An important point to note is that the ADF and ATC radios will not drop directly onto the DZUS rails fitted within a real B737 center pedestal. 

SISMO modules have been designed so that the electronic boards, mounted directly beneath the panel, are flush to the edge of the module.  What this means is that the unit cannot be placed directly onto a rail, as the electronics board abuts the edge of the rails. 

LEFT:  The two tabs overlap the DZUS rails.  You must cut the DZUS rails to allow the module to fit the pedestal.

To allow correct placement in a genuine center pedestal requires that the DZUS rails be cut in the appropriate position.

All the other SISMO modules, other than the ATC and ADF modules drop onto the rails without an issue.

Misleading Information

During my initial research, I asked SISMO if their modules fitted a genuine center pedestal.  Juan Ma stated they were compliant and did fir genuine DZUS fasteners; however, when they didn't fit the rails, Juan Ma claimed he had misunderstood my question due to his poor understanding of the English language!

To utilise genuine DZUS fasteners, you will need to enlarge the attachment holes in each of the modules to allow the fastener to fit the hole.  A word of caution here – SISMO use plastic backing boards which will crack easily if you are overzealous with a power drill. 

This is why I mentioned earlier that modules that incorporate metal plates in their construction are a better investment.

Communication and Support

Support for SISMO is either directly via e-mail or by their dedicated forum.  All e-mails are answered quickly (in English or Spanish).  

All my e-mail communication with JuanMa and Cristina has been on a very professional level.  They are courteous, exceptionally patient and very helpful; both strive to help you as much as they can.  

SISMO Modules - a closer inspection

ADF Radio Module

Initially, you’re impressed when you look at the ADF modules.  The seven segment displays, illuminated in either amber yellow or warm orange are easy to read, well lit and look similar to the displays you would see on a real aircraft. 

As you turn the rotary knobs to change the frequencies there is no catching as the knobs are turned and the push-to-activate buttons do not stick in the down position when depressed. 


One small issue I immediately noticed was that the tinted window plate which sits over the frequency display is not secured; as opposed to other manufacturer’s modules that incorporate the plate into the actual construction of the module.  If you invert the modules the cover plate will fall out of the recess.  I decided this wasn’t a problem as how often are simulators inverted, and securing the plate is an easy exercise; a small piece of double-side tape is all that is needed.

My problems began after roughly four hours of use.  The frequency push-to-activate button was temperamental and would not allow the stand-by and active frequency to be changed with one push; several pushes were required.   The problem is intermittent, but it suggests an issue with clicking mechanism or the button itself.

The next issue to develop was with the rotary knob; turning the knob caused the frequencies to jump digits.  As with the push-to-activate button, the problem was intermittent but, was rectified when you closed and reopened the SC Pascal script.  Perhaps the script needed tweaking.

Knobs and Switches - Poor Quality

I was disappointed with the switch knobs used by SISMO.  The two ADF-ANT switches are hand injected low quality “plastic” (?) and have several small injection holes within each of the knobs.   For the minor cost involved, it would have been nice to use high quality machine-injected knobs.  

Each of the ADF-ANT switches slides onto and over the plastic circular shaft of the rotary mechanism.  The knob is then secured to the shaft by two grub screws each side of the knob.  It doesn’t take too long for the grub screws to become loose resulting in the knob slipping. 

Other companies have solved this potential problem by using D-shaped shafts or higher quality rotary switches incorporating metal shafts instead of plastic.

My rating 4/10

Audio Control Panel (ACP)

The Audio Control Panel (ACP) replicates the audio system of the B737 (navigation radios, etc).  The ACP occupies a large piece of real estate in the center pedestal and the ability to turn on and off navigation audio sounds should not be dismissed.

LEFT:  SISMO ACP unit does not look realistic with inexpensive poorly moulded buttons and very stark backlighting.  Note that some of the rectangular buttons are not in alignment.  This unit has been constructed with very poor attention to detail.  Note black knob is not a SISMO knob.

The main ACP switch is of similar construction to the ADF-ANT switches on the ADF module; it is poor quality with injection holes readily observed.  The clear push buttons used to turn on and off the various audio sounds are of low quality.  The buttons are fashioned from clear acrylic and lack detail and definition.  

I was disappointed that when the ACP unit was fitted onto the pedestal, light from the rear LEDS seeped through along the edge of the module (to stop this I applied masking tape to the side of the panel to create a light skirt.  I have also noted that some of the buttons are not accurately aligned with one another. 

Often it’s the small things that count and push a product to the next level. 

I was not impressed with the quality and attention to detail on the SISMO ACP unit; therefore, have decided to convert two real B737-500 ACPS to simulator use.

My rating 2-10

Rudder Trim Module

The rudder module incorporates a large knob that is center-spring loaded.  The knob allows the rudder to be deflected in either direction and be recorded in degrees of offset on the scale.  The movement of the defection needle is made possible with the use of small servo motor fitted beneath the module and powered by 12 volts.

The rudder trim knob is poorly moulded and shows hollow holes left over from the injection process.  For those searching for aesthetics, replacement using a real B737 knob is very easy (if you can find a real knob).

LEFT:  SISMO rudder trim module.  Note the very poor moulding on the knob and colour shift with lighting.

The trim needle, at least on my module, is a little lop-sided.  As with the ACP module, stray light from the LED back lighting is readily seen around the edge of the module.  Like other SISMO modules, there is no inclusion of a light skirt to stop straying light.

The remainder of the module is aesthetically pleasing.

The rudder trim is one of the modules that is necessary to complete a center pedestal, but unless one is regularly flying with one engine, the module is seldom used.  Therefore; this module from SISMO, even with the irregularities, is a reasonably priced alterative to some of the more expensive counterparts available.

My rating 5/6-10

ATC (Transponder) Module

This is one of the better produced modules from SISMO. 

The switches and knobs are well presented, there are no injection holes in the knobs, and the operation is very smooth when altering frequencies. The digital read out is crisp, yellow amber in colour, and the tinted window, which falls out easily on the ADF modules seems to be more secure (although it is the same drop in type).   As with the ADF modules, this module will require you to cut the DZUS rails if you are using a genuine 737 center pedestal.

As a script was never supplied with this module (SISMO did not send it), I cannot provide information to how well it operated.  

My rating based solely on appearance is 8-10

Reliability and Performance - Software and Modules

Software - SC Pascal Scripts

The modules require SC-Pascal scripts to be installed on the computer of your choice. 

The basic script is downloaded from the SISMO website.  A further “customised” script is needed to configure the modules to the avionics software package you are using (Sim Avionics, Project magenta, ProSim737, Orion, etc) and FSX.  SISMO generate this script for you and all you need to do is run the executable file when you open a flight session.

SC-Pascal scripts are completely new to me, but a little research indicates that the script is used as a software interface between the actual functionality of the avionics modules and FSUPIC / FSX.

Once the scripts are installed and configured correctly, a folder is created in which is stored the config.ini file and the executable script.  The folder and files can be named and stored anywhere on your computer system.   Activation of the modules is achieved by activating the executable script.  

Optionally, direct access to the script can be made by adding the executable command to the auto start folder of your computer.  This option automatically starts the modules when the computer is turned on.  The script then runs in stand-by mode until FSX is activated.  This saves time and repetition having to turn on the SISMO modules separately.

As SISMO utilises Ethernet technology, the various IP addresses of the computer (s) you are using need to be correctly configured to allow communication between the computer and the modules.  This is basic networking knowledge and is relatively easy to learn.

Once the software is configured, the software and modules should operate flawlessly.  

Script Problems

I did have some issues with the SC Pascal script freezing when it was initiated.  The script also caused some issues which appeared to cause the ADF radios to incorrectly display frequencies.  To Juan Ma's credit, he did tweak the script, however, the problems remained.

As I know nothing about SC Pascal scripts, I do not know with certainty whether the problems experienced were caused by a script issue, hardware issue, or something particular to my system.  I believe the issue may have been the SC Pascal script.

For those who know me, I try to keep things simple, and running multiple scripts for this and that does not exactly fit into this "ethos".  There already is the proven and tested FSUPIC, WIDEFS and configuring functionality through ProSim737.  Why complicate matters..... (I have learnt this lesson from experience...)

It would be inaccurate to state that SC Pascal scripts don't work, because there are many simmers who have them operating perfectly.  But, I am not one of these individuals.

Note that at this time using Sim Avionics and NOT ProSim737 avionics suite.

Quick List - Pros and Cons


  • Fairly accurate 1:1 ratio (or close to)
  • Easy to install and use software (knowledge of SC Pascal required if altering software)
  • Laser cut and stencilled lettering
  • Ethernet technology


  • Plastic shafts on ADF-ANT knobs (should be metal/stainless)
  • Poor quality knobs and switches on ADF, ACP and Rudder Trim module
  • Average light coverage for LED back lighting
  • ADF and ATC modules do not drop directly onto DZUS rails
  • Large number of cards needed for operation
  • Not DZUS complaint (requires existing holes to be enlarged)
  • Plastic backing plate (easily damaged when enlarging holes for DZUS fasteners)
  • Light seepage around edge of some modules from back-lighting (no light skirt)
  • SC Pascal script troublesome and works intermittently.
  • Poor quality paint work
  • Considering the above, expensive

Overall Opinion

The modules are ideal for the budget-conscious flight simmer.  

The lack of quality knobs, switches and poor attention to detail detract aesthetically, while the large number of cards that need to be installed can make installation challenging.  Three failing LEDS and problems with the frequency selector switch on the ADF radio unit may point to quality assurance issues.  The use of Ethernet over USB is highly commended and may reduce information bottlenecks.

My rating for the software is 4/10 (The supplied scripts did not work with my system, which at that time was Sim Avionics and not ProSim737).

My overall rating for the modules is 3/4/5-10 (based on fitting issues, quality of knobs, poor attention to detail, poor painting, no light skirts and temperamental frequency selection switches on ADF).

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



I have returned all the modules, cards and wiring  to SISMO for refund

Initially, SISMO offered me 10% of the value of the products purchased (this included I/O cards that had never been used).  

SISMO stated that the return period had been exceeded, and any products returned would be treated as second hand units.  It didn’t matter that SISMO had not, at that time, sent all the appropriate SC Pascal scripts to ensure correct operation of the modules.  

The writing of the SC Pascal scripts was delayed close on 2 months after I received the modules, and when received, the scripts did not operate as intended.  Excuses were; staff holidays, workloads, Easter break, and awaiting confirmation from another company to facilitate operation.  

Upon receipt of the returned items, SISMO claimed that many of my issues were incorrect or not relevant.

  • They claimed that the modules had been damaged.
  • They stated that I had broken the LEDS (I told them the LEDS were not working when I received the parcel).
  • They claimed I had disassembled the units and damaged the paint and screws.
  • They claimed I had re-painted portions of the units.
  • They claimed sticky plaster was attached to one of the units. (true as I used tape to secure the wiring together when I returned the units & also to create a trial light skirt)
  • They deducted from my refund, import duty and inspection fees, when I returned the goods to Spain.
  • They claimed I did not include paperwork (which I did). 
  • They stated that as the ATC RADIO module was discontinued, a refund was not possible.

I am not going to go into a long account to what has transgressed.  But, I will say that this company cannot be trusted…..They promise the world to you, but if you are not happy with the products, they provide every excuse possible to NOT provide an adequate and reasonable refund.

For example, when I reported the failure of the LEDS to SISMO, their response was “they worked when they left here”.  They did offer to replace the LEDS but, at my shipping expense.  They did offer a discount on further purchases due to the inconvenience.

It should also be noted, that in my initial correspondence with SISMO, I asked whether their modules would drop directly into a real B737 center pedestal.  Juan Ma stated “YES”.  However, on receipt it was discovered that the modules were too large to fit directly onto the pedestal DZUS rails.  I queried Juan Ma from SISMO on this; he stated that it was a language misunderstanding.

Juan Ma understood perfect English when it came to avoiding refunding my purchase money.

Legislation, PayPal and Delays

Spanish legislation states that every purchase has a 7 day cooling off period, in which a return and refund can be made.  PayPal policy states you have 45 days in which to make a claim.  EU legislation states that refunds are possible if items do not function correctly - within set time frame.

Without a working script for Sim Avionics (which took two months to receive), how can testing of modules occur!  Because of the approximate two month delay on sending operating scripts to me, all these options had expired.

I cannot help but think that SISMO delayed the sending of the scripts so as to provide a reason for NOT refunding 100% of the purchase price.

SISMO Solicones appears to be a company that will ONLY support and stand by their products if you want to purchase something or want to use it. 

If you ask for a refund on faulty components, components that do not work with your choosen avionics software suite, or scripts that do not function correctly, then expect NOTHING, or at the very least, a minimal refund (and you will have to fight to get this refund). 

What you can expect from SISMO, is e-mail after e-mail informing you that you have no right to refund, that you have damaged the items, that you did not follow SISMO policies, etc, etc.

After many e-mails I succeeded in gaining a E400 Euro refund for an initial E1400 Euro outlay.

I am sure there are many happy customers using SISMO product; however, I am not one and I do not recommend SISMO Solicones.  The quality of their products is poorly executed, attention to detail low, and attempt to maintain good customer relations non-existent (I was returning items)...

In my opinion, it is VITAL that a company standby and support their product-line, and this includes refunds if the product (for whatever reason) does not operate with your simulator set-up.

If you search the Internet, you will find very few comments regarding SISMO, other than company endorsed reviews on forums that are supported by manufacturers and resellers.

If you are searching for quality avionics modules, look no further than Flight Deck Solutions or CP Flight

These two companies are reliable, produce good products and provide exceptional after sales service.  They also offer a refund if not 100% satisfied with their product.  Whatever you do, don’t spend your money on inferior products from SISMO! (my opinion only).

  • This review is rather negative towards SISMO Soluciones; however,  I have "toned down” my anger to this company to produce a balanced and accurate review.  Please understand that this is my experience with this company.  Your experience may well be positive. 

The avionics panels/modules I am currently using are genuine Boeing items converted to FS use and modules made by Flight Deck Solutions and CP Flight.

Feel welcome to make comments, either good or bad in the comments section.


Replacement Genuine 737 Throttle & Center Pedestal - Full Conversion to NG Style

The last few months have seen quite a bit of activity regarding the throttle quadrant and center pedestal, which has culminated in me selling my former 300 series TQ and pedestal and replacing it with an another unit from a late series 500 airframe.

Brief Recap

In an earlier post late in 2012, I decided to convert the 737-300 throttle to full automation.  A dilemma I faced was whether to keep the throttle unit as a 300 series throttle with the attached two-bay pedestal, or do a full conversion to make it similar to the Next Generation (NG) style. 

After careful consideration, a decision was made to convert the throttle quadrant to a full NG style, bringing the throttle units and center pedestal in line with a 737 NG airframe for which the MIP is designed.

Stab Trim Switches

One of the biggest differences, apart from thrust lever handles, between early model throttle units and the NG units is the stab trim cut out switches.  On the earlier 300 series units, the switches are paddle / lever style switches while the NG uses toggles and T-Locks.  T-Locks are a safety feature and sit beneath the toggle switches and are spring loaded; the pilot must push down the T-Lock to activate the toggle.  

LEFT:  737-300 TQ with old style paddle-style stab trim levers.

To convert the trim switches requires cutting out the old switches and fitting new reproduction NG style switches.  This is a major task requiring precision work of a surgical nature.  Although reproduction switches can be made, the reproduction T-Locks don't operate as the real T-Locks should.  I did search for some genuine T-Locks and toggles, however, my search was fruitless as these parts appear to be reused by airlines.

Replacement 500 Series Throttle Quadrant & Three-Bay Center Pedestal

A friend of mine informed me that a late model 737-500 throttle quadrant was for sale.  This unit was in better shape than my existing throttle, included the genuine 'NG style' stab trim switches complete with T-Locks, and also had a three-bay center pedestal.  It appears provenance was shining on me as the new throttle appeared for sale a day before the stab trim switches were about to be removed (with a metal cutter...)

The throttle and center pedestal were purchased (you only live once!) and the 300 series unit sold to an enthusiast in Sweden.

NG Conversion

To bring an earlier style throttle and center pedestal in-line with a NG airframe requires, at a minimum:

  • Attachment of a NG style throttle lever shroud to existing aluminium levers;
  • Removal of TO-GA buttons and relocation to bring design in-line with a NG (the buttons are identical, but the housing is different);
  • Possible replacement of the stab trim switches;
  • Painting of throttle housing and center pedestal from Boeing grey to Boeing white; and,
  • Painting of all throttle knobs from Boeing grey to Boeing white.

The biggest hurdle is usually replacing the trim stab switches, however, as these are already present on the new throttle, and are the NG style, considerable time and expense was saved in not having to replace them.

Main Differences - NG & Classic

The Boeing airframe that most people associate with today begins with the 737-200 and ends with the 737-800 NG.  In between we have the classics which refer to the 737-300, 400 & 500 series airframes and the NG, which stands for Next Generation and incorporates the 737-600, 700, 800 & 900 series airframes.

The main differences between a classics and NG throttle quadrant are:

  • The stab trim switches are slightly different; the classics having two flat levers while the NG has toggle-style buttons with T-locks;
  • The throttle thrust lever handles; the classics are bare aluminium and the NG is white aluminium that is ergonomically-shaped.  The TO/GA buttons are also positioned in a different place on the NG.  The knobs (handles) on the levers are also coloured white rather than off-grey;
  • The method that the throttle thrust levers move during automation.  The classics move both thrust levers together when auto throttle is engaged.  The NG moves each lever individually in what often is termed the throttle dance (this is due to the computerised fuel saving measures incorporated in the NG);
  • The spacing (increments) between each flap lever position is identical in the NG, but is different in the earlier series throttles;
  • The center pedestal in the classics is either a two-bay pedestal (early 300 series and before), but more likely a three-bay pedestal.  The NG always has a three-bay pedestal.  Base materials for the center pedestal are also different - aluminium verses a plastic composite material;
  • The speedbrake knob is very slightly more elongated on the NG unit; and,
  • The telephone, circuit breakers and mike assembly differ in type and location

NG Skirt - Thrust Levers

Boeing when they designed the NG style throttle didn’t design everything from new; they added to existing technology.  All NG throttles utilise thrust levers which are identical to those of earlier units.  

Boeing designed a shroud or skirt that attaches over the existing thrust levers encapsulating the older thrust levers and sandwiching them between two NG style pieces.  The assembly is made from aluminium and is painted white.

The TO-GA buttons are located in a different position on the Next Generation units, although the buttons used are identical.

To alter the position of the TO-GA buttons you must detach  the small aluminium box from the 300 series thrust levers, remove the TO/GA buttons, and then re-solder the buttons in the appropriate location on the new unit.

I did not make the NG skirt for the thrust levers, but rather had fabricated, from design specifications, a reproduction skirt.  The skirt is produced from aluminium and replicates the dimensions of the Boeing part.

Time-line, Functionality and Conversion

The TQ is initially being converted in the United States.  The advanced work will be done by a good friend in California, and then by myself after delivery.

The replacement unit will feature several imrovements which will allow: full motorized functionality, full speed brake capability, accurate trim tab movement, alternate trim wheel spin speeds, correct park brake release, trim wheel braking and several other features. 

I want the functionality of the TQ to be as close as possible to that found in the real aircraft; therefore, the methods used to ensure this functionality will be slightly different from the norm.

When the TQ is fully functional and tested, I'll publish a post providing further information and detailed photographs of the various functions.

It is hoped everything will be completed, and the TQ and pedestal installed by late May 2013.  The next month or so will be quite exciting.

Two-bay Pedestal Will Be Missed

I know I will miss the narrower two-bay center pedestal.  A major advantage that will be lost is the ease in climbing into and out of the flight deck; the two-bay provided more room between the pedestal and the seats.  At some stage, I probably will need to install J-Rails because the seats I'm using are fixed-claw feet Weber pilot seats; J-Rails will be needed to allow lateral seat movement.

BELOW:  Montage of several images showing main visual differences between 737-300 classic series throttles and the 737 NG style throttle units. The 300 series TQ is my old throttle unit but, the NG TQ belongs to a mate of mine.


B737-300 Throttle "Full Automation" Upgrade

The throttle quadrant installed in the simulator is from a B737-300.  When I initially  converted the throttle for flight simulator use, I choose to not have full automation included; automation being at the time fraught with issues in relation to correct and accurate operation.  

Technology rarely remains stationary and after one year of operation I’ve been reliably informed that automation can now be implemented without the problems previously experienced.  Therefore, I’ve crated the TQ and it’s now on its way to the US via DHL courier for conversion to full automation.  A process I am told that will take a few weeks.

LEFT:  B737-300 throttle (formally used by South West Airlines).

Automation will include, at the minimum, the following:

  • 4 speed trim wheels dependent upon aircraft status (as in the real aircraft)
  • Accurate trim tab movement
  • 9 point speed brake (speed brake operation as in the real aircraft)
  • Full automation of throttle thrust handles as per MCP speed window and/or CDU
  • Hand brake release by depressing brake pedals (as in the real aircraft)

I don’t mind admitting that that my building abilities don't include complete knowledge on how to convert a B737 throttle correctly - especially in relation to automation; therefore, this task has been outsourced.

The method in which automation will be achieved is slightly different from the usual way throttles are converted, and includes some "magic" programming of chip sets and machining of parts to allow compatibly with ProSim 737.  Taking into account Christmas and New Year, I'm hoping that the machining, installation, configuration and testing will be completed by January (2013) and the throttle will be re-installed into the simulator by February.

In a future post I'll explain the process of conversion, and how automation has been achieved with minimal use of add-on software.

Idle Time

Although the throttle quadrant and pedestal will be absent from the simulator for a short time, work will not be idle.  The conversion of the twin real B737 yokes and columns has been completed and I'm finalising installation of the second platform which incorporates linked B737 rudder pedals.  I am hoping this will be completed by mid-November.  I have discussed the new platform in a previous post.


JetStream 738 by ProSim737 - Review

After flight testing several aircraft models, I decided to use the B738 (FS9 version) produced by Precision Manuals Development Group (PMDG).  This flight model, once the PMDG flight logic is removed, functioned exceptionally well and is very stable.   

One of the potential problems when using a flight model produced by another company is compatibility and functionality with your chosen avionics software suite.  Minor problems are often solved by tweaking the aircraft.cfg file; however, tweaks are just that, and often issues will occur which cannot be identified and rectified.  In my experience, tweaking the .cfg file may solve your initial problem, but may cause additional errors elsewhere.

Different Aircraft Models – Different Solutions

To ensure various aircraft models operate with their software, Sim Avionics provide users with specific aircraft.cfg files that correspond to the particular flight model they are using.  These files are optimally tweaked to the Sim Avionics software.

ProSim737 has handled the problem of aircraft model variances slightly differently.  Rather than provide a tweaked aircraft.cfg file to allow you to use whatever flight model you wished, they took a holistic approach and produced a complete aircraft dedicated ONLY to their avionics software suite.

Creating an aircraft model that is designed to only operate with their software has many advantages.  First and foremost is trouble-shooting.  Everyone is using the same software, meaning that if a problem does present itself, finding a solution is usually easier.  Chasing ghosts rarely occurs as the same company that produced the avionics suite produced the aircraft flight model.

At this stage, you may think that ProSim737 only works with their dedicated aircraft.  This is incorrect; ProSim737’s avionics suite will work with numerous aircraft models including the default FSX 737 and the PMDG FS9 737, however, if you want to achieve harmonious inter-connectivity with the avionics software, then using the dedicated flight model is highly recommended.

Hello “JetStream B738”

The JetStream aircraft is more a flight model than an actual virtual aircraft.  Don’t expect to see “wow” factor visuals with this model.  Instead, expect to experience “wow” factor flight dynamics that work in perfect unison with the flight avionics software.

Virtual pilots using a fully developed simulator often do not need what is offered in many aircraft models: virtual flight decks, pop-up gauges and GPS consoles are not necessary.  As such, the JetStream doesn’t provide these additives.  You will, however, see the default FSX panel layout of the B737.  This can easily be permanently removed by either editing the panel.cfg file or removing the panel images.  


The JetStream software comes with an .exe installer.  Installing is as easy as following the prompts.  When installed, a JetStream 738 folder will be found in the simobjects/aircraft folder.

JetStream Textures

The Jetstream uses the default texture pack belonging to the B737-800 FSX aircraft; therefore, the outside views mimic the same texture details seen on the default FSX model.  

I think the outside textures (especially with a repainted airline livery) are just as good as many payware add-on aircraft textures.  Certainly, PMDG NGX textures surpass the JetStream textures, but you must remember that the aircraft has NOT been designed as a pretty aircraft to look at, but a flight model to read and accurately output defined flight dynamics.  Think of it as flying “ones and zeros”.

Video Makers & Virtual Airlines

Video-makers or those who wish to mimic a particular airline can easily re-texture the aircraft skin to reflect a specific colour scheme or airline livery.  Search through the ProSim737 forum and you will find several dozen repaints.  Installing additional textures is identical to the method used in FSX.
If you search this website you will find mention of the 164 liveries pack.  This pack provides many liveries and re-textures.

Outside Views & Animation

Many individuals concern themselves with the outside view of an aircraft.  Whilst it’s enjoyable to inspect the aircraft from the outside, the quality of the external visuals has absolutely nothing to do with the way the flight model behaves.                    

This said, the movement of essential equipment can be observed: the rudder, flaps, ailerons, spoilers and landing gear.  Landing and other outside lights are also replicated including a functional taxi light which is bright enough to “read by”.  The outside view is far from sterile.

Taxi Light – Too Bright & Intense

One downside to the external view is the actual positioning the taxi light.

Historically, Micro$oft have never animated the taxi light correctly.  ProSim737 have created their version of a taxi light, which is more a ball of light than a taxi light.

The taxi light is bright – very bright.  On lift off, the fall of the light beam covers the lower portion of the front screen view.  This obviously does not occur in a real aircraft.  Although I have not altered the files, I have been informed that this cosmetic issue can be rectified with a small tweak to the aircraft.cfg file.  

I would have liked ProSim737 to have developed the external lights from scratch with a dedicated taxi light with no fall off on the lower portion of the computer monitor.  Good external lights are essential if you fly predominately at night.

Flight Dynamics – flying Ones & Zeros

This is why the JetStream was developed – as a platform to replicate complicated flight dynamics to realistically mimic the movement and handling of a real jet aircraft.  This is where the “wow” factor begins and is where the JetStream leaves it’s contemporaries behind.
I am very impressed with the flight dynamics.  During several hours flight testing, the model was exceptionally stable, handled as you would expect, and interfaced with the ProSim737 logic flawlessly.  

Fine-Tuning & Stability Testing

ProSim737 has been designed to be operate with MCPs (Main Control Panel) manufactured by several companies.   I have been informed that, depending on the MCP type, problems can be experienced with the sensitivity of the auto pilot.  To alleviate this, ProSim737 allows the sensitivity of the MCP to be adjusted.

The JetStream manual suggests that a good method to determine possible over-control (i.e. oscillations) is to increase the simulation speed to 4x and observe if oscillations occur, and if the autopilot is able to hold either heading or altitude”.

I performed this stability test at x4 acceleration and noted very mild pivoting of the wings as the aircraft slewed along it defined navigation track.  When I morphed back to normal speed, the aircraft was in the same direction, attitude and altitude that it was when I entered acceleration mode.  Only at faster acceleration speeds (x16) did the aircraft loose position (which is to be expected).

Hardware Calibration

The JetStream requires careful and fastidious calibration of your yoke and rudder pedals to ensure solid performance.  

Calibration isn’t as important if you use the auto pilot to do most of your flying, however, if you prefer to hand fly to and from FL10, correct calibration of your yoke and rudder is paramount.
It’s essential to take the time to calibrate your hardware correctly using the Windows and FSX calibration tool, using FSUPIC to fine tune the results.

Your hardware control settings play a huge role in how the plane behaves, so before blaming the flight model, please test it with different controls and settings.  

The following is an excerpt from the JetStream read me file:

  • Most 738 models available represent a truly overpowered engine/dynamics ratio, The flight model tries to follow the real curve, don't expect it to reach high speed/AOA values as other flight models do, especially immediately after rotation.
  • As in FSX, nose-steering is nothing else but rudder, without FSUIPC's given steering routine and a hardware wheel, do not expect acceptable results on the ground.
  • The VC was deliberately removed from the model.
  • Trim related values do depend on hardware behaviour.  This relates to whether hardware has been calibrated with or without FSUIPC.
  • Idle N1 value is OAT dependent. You will get 20.7 at 15C.
  • Set General Realism Slider to Maximum! It is vital for the model!

PMDG (FS9) and Default 738 Verses JetStream

I outlined in the opening paragraph that ProSim737 can be used with several other add on aircraft, including the default FSX 738.  My limited testing proved that these aircraft fly well with ProSim737, however, nuisances do occur and tweaking of the aircraft .cfg file is needed to solve niggling problems with often undesirable outcomes..

The JetStream was designed from the bottom up to be the flight model for ProSim737.  Therefore, many of the nuisances observed when using other flight models do not exist.

As an example, the FS9 version of the  PMDG aircraft at Vr, with the yoke pulled to aft position, exhibits a slight delay of a second or two before actually lifting off the runway.  A positive rate is rarely achieved before V2 is called.  This is completely different with the JetStream which is far more responsive.  Pull back slightly on the yoke at Vr and the aircraft is airborne before reaching V2.

No matter what I did with the PMDG flight model, the only way to achieve rotation at Vr was to pull back on the yoke a few seconds before actually hearing the Vr call out.

This is but one example, illustrating why it’s solid sense to link a dedicated flight model to a specific avionics software suite to achieve harmonious integration.

FS Add Ons - Top Cat Compliant

Many virtual pilots use a popular add on flight tool called Top Cat.

Top Cat is used, amongst other things, to calculate weight, takeoff and landing performance.  The JetStream is compatible with Top Cat and the JetStream manual explains how to incorporate this advanced FS add on.

JetStream User Manual

A detailed user manual is included which is well written and informative.  It’s important to read this manual to ensure you get the most from the JetStream flight model.

Updates & Improvements

ProSim737 currently produces one aircraft and one avionics software suite.  While some may find this lacking, I find it reassuring.  Rather than become tired down to developing other aircraft and software, ProSim737 focus their attention on one aircraft – the B738.  This translates to regular updates and improvements which can only benefit the end user.


Support is provided either by a dedicated forum or via personal e-mail communication.  

To date, all requests have been answered quickly and efficiently.  If you need help, support is available.  You are not left to feel as if you’re withering on a vine, waiting for assistance.


I try to be impartial and accurate when I make a review, however, if I have missed something or have made a mistake, feel free to make a comment.

This review is based solely on my experience with the JetStream and ProSim737.  I have no affiliation with the company.

My Rating is 9/10