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)
« How to Update and Troubleshoot Problems with the ProSim737 Avionics Suite | Main | Repair Backlighting on Throttle Quadrant »

Correcting Lag in ProSim737 Weather Radar

This short article relates only to the ProSim737 avionics suite.

The software that controls the avionics suite enables many features to be displayed on the Primary Flight Display (PFD) and Navigation Display (ND), and it's paramount that the PFD and ND display the best possible rendentation of the avionics that is possible.  Anything less will detract from the simulation experience.

ProSim-AR (the developers of ProSim737) are constantly updating their software to facilitate new features, functionality, and improve on existing functionality within the avionics suite.

One area of improvement recently implimented has been the detail that the terrain and weather (from the weather radar) is displayed on the ND.  

Performance Issue

Although the improvement is welcomed, many enthusiasts have reported performance issues when the terrain, or more specifically, the weather radar is displayed.  The condition usually becomes worse when other functionality, such as waypoints, airports, stations, and data are also selected on the EFIS to display on the ND (in addition to terrain and weather radar).  

The performance spike presents as a stuuter, lag, or pause, and this becomes more evident when the aircraft is climbing or banking; the altitude tape in the PFD stutters, as does the compass rose as it moves to a new course heading.

Attempting to Resolve Lag

ProSim-AR have attempted to resolve the issue of lagging, by releasing an alterative method to how the software interprets and displays the data (Direct2D).  Although the use of Direct2D has been ‘more or less’ resolved the display lag or stutter, other problems have surfaced such as the positioning and clarity of the displayed fonts.

It’s important to realize that the lagging issue is not a direct result from a low performance computer or graphics card.  Although using a high-end computer and graphics card will help to provide the necessary ‘grunt’ to display the data without any lagging.

Possible Solution to Lag

On my simulator set-up, I was using one computer monitor and one instance of ProSim737 (ProSim Display) to display the data on the PFD and ND.  Using this combination, my set-up always exhibited lagging and stuttering.  

Recently, I decided to run one instance of ProSim Display for the PFD and another for the ND, while displaying both the PFD and ND on the same computer monitor.  In other words, I seperated the resources that are used to display the PFD and ND.

I was surprised that this combination resolved the lagging problem.  I can now operate the ND with waypoints, airports, stations and data, and change between the weather and terrain display without any major lagging being evident on the altitude tape of the PFD or ND compass rose (assuming the aircraft is climbing and/or banking).


Setting up the two instances of ProSim Display to feed directly to one computer screen is straightforward.  However, configuring the position of the PFD and ND so that they are adjacent to each other and can be seen simultaneously can be ‘tricky’.  It does take a little bit of time to set up.

Prior to changing anything, always make a back-up copy of your config file.  This file, amongst other things, contains the last position of your various displays on the computer monitor.  The config file is located with the ProSim Display folder.

Excess Data Display

The ND will often display the words 'Excess Data'.  This message indicates that the ND is not capable of displaying all information.  If you deselct an ND option on the EFIS, the display will usually extinguish.  The display also appears on the the ND in the real aircraft.

The message can be disabled in the ProSim737 Instructor Station.

Final Call and Disclaimer

This simple proceedure resolved the issue of lagging on my simulator set-up, however your ‘mileage’ may differ.  Each computer is unique and the results I experienced may not be replicable on your set-up.

If it doesn’t work, then delete the config file and replace it with the backed-up copy.  This will revert the position of the displays to your earlier set-up.  

At the time of writing this article, I was using ProSim737 Version 219b10 with Lockheed Martin P3D Version 4.4 and 4.5.

PrintView Printer Friendly Version

EmailEmail Article to Friend

Reader Comments (1)

Hey Willow

Thanks a million. It works! I now have very little stutter. THANK YOU Ric
June 5, 2019 | Unregistered CommenterRichard Hay

PostPost a New Comment

Enter your information below to add a new comment.

My response is on my own website »
Author Email (optional):
Author URL (optional):
All HTML will be escaped. Hyperlinks will be created for URLs automatically.