CSS 737 Delayed
May 22, 2025
CSS 737-500 Review – A New Classic Lands in Flight Simulator
Note: It's important to note this review is based on V1.0.0 - as updates are released, I'll cover them as best as I can.
After a short delay, Commercial Simulation Systems (CSS) has officially released the highly anticipated 737-500 for Microsoft Flight Simulator (MSFS). This marks the first aircraft in their planned 737 Classic series, and it’s already stirring up serious attention in the flight sim community. As of now, only the 737-500 variant is available, so this review will focus exclusively on that model. Let’s dive into everything this release has to offer — and address a few misconceptions along the way.
Debunking the Virus Rumors Around the CSS Launcher
Before getting into the aircraft itself, let's clear up some misinformation circulating online. Some users have voiced concerns about the CSS Launcher being a "virus" due to warnings from antivirus programs and Windows Defender. Here's the reality
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The CSS Launcher lacks a publisher certificate, triggering Windows to flag it as from an “unknown publisher.”
- During installation, it drops executables into a temporary directory (e.g.,
C:\Users\admin\AppData\Local\Temp\RarSFX0\CSS_Installer.msi), which is a common red flag for malware, but not definitive proof
For those still unsure, a more detailed breakdown of the installer's behavior can be found here on Any.Run. This is a false positive scenario — and not a virus.
Lets dive into the review
The Launcher: Simple, But It Works
The CSS Launcher is the gateway to purchasing and installing the aircraft. It’s basic and faced some early load issues during launch due to high demand, which made registering accounts or activating purchases difficult for some users.
While it would be ideal to have account and purchase management on their website, the launcher ultimately gets the job done. Installing the aircraft and liveries is a smooth, one-click process.
Visuals and Modeling – A Beautifully Done Classic
The visual fidelity of the CSS 737-500 is undeniably impressive. The engines and wings are standouts, and while there are a few minor bugs being actively fixed, the overall modeling is top-tier.
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The aircraft captures the essence of the Classic 737 era, complete with CRT displays and steam gauges in the cockpit.
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A functioning lavatory, interactive flight attendant panels, and a detailed cabin add an immersive layer.
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In some areas, it even outshines PMDG, whose 737 feels more like a P3D port than a native MSFS experience.
Wing Flex That Feels Real
The wing flex animations are stunning and add to the realism of flying through turbulence. It’s subtle when it should be, aggressive when it needs to be, and adds a visual layer that’s often hard to get right.
Systems Overview – Solid, But Not Flawless
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Weather Radar: It’s functional but basic — still great to see this included.
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LNAV/VNAV: Generally works well for VATSIM flying, though LNAV can occasionally produce aggressive bank angles if it deviates from the flight path. VNAV occasionally lags behind.
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Flight Model: A highlight. The aircraft is challenging and rewarding to hand-fly. It's easy to fall behind the airplane, making it feel like a true retro flying experience. That said, crosswind behavior feels a bit exaggerated — hopefully something the team refines.
EFB – Functional, Feature-Packed, and Fun?
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Includes SimBrief and Navigraph integration.
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Handles performance calculations with ease.
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Even comes with built-in mini-games (yes, card games!) to keep you entertained during cruise. A fun, quirky addition not seen in other aircraft.
Sound Design – The Only True Letdown
While not awful, the sound design is currently one of the weaker points of the product. With competitors like Fenix and IniBuilds setting the bar high — and community legends like Borris producing studio-level sounds — the CSS 737 Classic feels a bit underwhelming in this department. The good news? Future updates could bring big improvements here.
flightdeck2sim - Youtube
Performance – Mixed Results Depending on Your Rig
Performance is another work-in-progress. While some users report decent frame rates, many (myself included) are experiencing 10–15 FPS drops compared to the Fenix A320 or Ini A350. This makes it one of the more FPS-intensive add-ons currently available.
Lower-end system users, be cautious. The CSS team is aware and actively optimizing.
- CSS 737-500 V1.0.0 - High of 23 FPS, low of 19 FPS
- Fenix A320 V2.3.0.524 - High of 35 FPS, low of 30 FPS
- iniBuilds A350-900 V1.0.11 - High of 30 FPS, low of 25 FPS
The FPS test is conducted on the same system, with the same settings, at the same time, and in the same weather conditions at the same location. As you can see, the CSS 737-500 on the current version falls a bit behind in performance compared to other aircraft. This will likely change in the future as updates come out and the performance gets addressed but at the moment. If you have a lower-end system and struggle with FPS on the Fenix A320 - be aware at the moment your performance will suffer a lot with the CSS 737 as of the current version
VATSIM Test – Real-World Style Flying Approved
I took the CSS 737-500 into a busy VATSIM session, and here's what happened
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FMC edits were smooth, even with route changes.
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Manual management of speed restrictions was necessary (as expected with an older aircraft).
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During descent and approach, I fell behind due to frequency changes and workload — but the aircraft held up beautifully.
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Holding patterns and late ATC vectors were handled without issue.
As you can see - this is a fairly unstable final, however after holding and constant changes. I just wanted to get down, there were some very light cross winds at 5-7 knots. However, I wouldn't blame you if you thought I was in 20-knot cross winds - a lot of correction is required to try to keep it stable for a touchdown. Although this isn't my best landing, it also shows how much hand-flying is required from a retro bird like this.
Pricing – High, But With Options
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Full purchase: $120 USD — one of the most expensive MSFS aircraft ever.
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Subscription: $5 USD/month or $50/year.
Is it worth it? That’s subjective. For a first release, CSS has produced something impressively complete, even if still evolving. The subscription option makes it easier for newcomers to try before committing.
Final Thoughts
The CSS 737-500 is a bold entrance into the MSFS aircraft market — and despite some launch turbulence and optimization issues, it’s a remarkably detailed and immersive experience. From its deep systems, beautiful modeling, and unique touches like a working toilet and flight attendant panels, this aircraft captures the true spirit of the 737 Classic.
If you're passionate about retro jets, like a bit of a challenge, or simply want to experience something fresh, this aircraft is well worth exploring.
Check it out now at css.aero
Legal Disclaimer
This review is purely based on my personal experience with the aircraft. I did not receive a free copy — I originally paid for a monthly subscription, which was later upgraded to a permanent license after a conversation with CSS. This did not influence the content of this review. All opinions are my own. Readers are encouraged to verify technical details and check for updates, as software evolves over time.
