There is a point in any long aircraft project where the news stops being about what the developers are building and starts being about what is left to fix. Judging by the latest update from Synaptic Simulations and iniBuilds, the A220 has reached it.
Fresh off FSExpo 2026, where the public got to sit down and fly the aircraft for the first time at the iniBuilds booth, the team has published its most detailed development update in a while. The headline, if you read between the lines, is that core development is largely done and attention has shifted to hunting bugs ahead of release. The team says it found only five new issues across three days of continuous demos at the show, fixed two of them on the spot, and had zero crashes. For a project that entered final testing back in March, these are promising stats.
A flight management system rebuilt from scratch
In the year since FSExpo 2025, the team says it gutted and rewrote the A220’s flight management system from the ground up, rebuilding it in just over 21,000 lines of code. The stated reason was a more stable and scalable foundation for the features the aircraft depends on, and the list of what that FMS now does is long: graphical flight planning, full lateral and vertical navigation, performance planning, crew alerting, vertical direct-to’s, configurable holds, and path offsets.
Graphical flight planning is the part most people will touch first. The developer says it ties into the A220’s Pro Line Fusion avionics and lets you edit the plan straight from the map, so you can click a waypoint to drop in a hold, activate a direct-to, reroute, insert a nearby fix, or toggle a fly-over. It will work with both the MSFS default navdata and Navigraph on release.
What stands out, though, is how much of the FMS’s awkward real-world behaviour the team has chosen to recreate. The developer points out that the real A220 caps out at 200 flight plan legs and six holds, and that its VNAV stops working entirely past 50 descent constraints. Rather than smoothing those limits over, Synaptic says it kept them. Go over the leg count and you get a FPLN FULL message, add one hold too many and the input is simply ignored, and touch a fix past the final approach fix and the approach cancels with a NO APPR indication.
The team also describes detailed performance planning across every phase of flight: FLEX takeoffs, climb derates, noise abatement departures, and temperature compensation on arrival, with fuel and arrival-time predictions that draw on SimBrief wind uplinks.
Systems that try to be convincing, not just present
The work that has gone into the systems is where the update gets interesting for the people who care about that sort of thing. The team’s stated goal is for every part of the avionics to feed from the correct underlying component, so the synoptic pages pull from the data concentration modules and the engine indications come from the electronic engine controllers, rather than from a simplified central model.
A few of the examples are hydraulic fluid that heats up as the system does work during flap or gear movement, battery temperature that rises with current draw, and the team even says it simulated the heat exchange between the hydraulic fluid and the fuel, so the fuel warms slightly as the fluid cools. The team has also added lag filters to many indications so they move smoothly rather than snapping, with transition times the developer says were matched to reference material. In their words, the aim was to take this from a good systems simulation to a convincing one.
There is a nice touch on the flight controls too. With the hydraulic system depressurised, the developer says the control surfaces react to gravity and strong wind. Flip the aircraft inverted and the elevators deflect the other way. The ailerons and spoilers stay put, since those are hard-locked when there is no pressure.
Flight guidance and approaches
On the guidance side, the team lists a large set of approach types: ILS, localizer, LDA, RNAV RNP down to 0.30, RNP AR, LPV, VOR, and VOR/DME. The developer says it has been testing these on VATSIM, and in some cases asked for RNP approaches that caught controllers off guard, pointing to group flights into San Diego on the RNAV RNP Z 27 where the aircraft tracked the path with little deviation. Autoland is in, with what the team describes as accurate timing for the RETARD, ALIGN, FLARE, and ROLLOUT transitions, plus the correct reversions when conditions are not right for it.
The vertical situation display shows the path VNAV intends to fly, and on approach you get the arrival runway and an ILS or LPV feather from the final approach fix. The developer notes the feather switches between a solid and dashed line on an LPV approach, just like the real aircraft.
Emergency descent mode is also in. Above 25,000 feet it can be triggered manually, or automatically if the cabin altitude climbs past 14,500 feet, and it brings the aircraft down to 15,000.
Sounds and visuals
The sound work continues with Echo 19, who has been on the project since last year’s FSExpo. The centrepiece is the A220’s so-called whale sound, the engine howl the type is known for. The developer describes it as a procedural effect driven by live engine parameters rather than a fixed recording, and attributes the real howl to pressure changes in the combustion chamber as the engines spool through around 30 percent N1. Synaptic says a dedicated sound update is coming later, so this is more of a preview than the full story.
Where it stands
So where does that leave us? The team says the remaining work is mostly bug fixing, with a few features still to finish and integrate. It says hundreds of issues have already been resolved and that fewer are turning up as testing continues. There is still no firm release date and no public pricing, and the team has stayed deliberately quiet on both, which fits its track record of not committing to a date until it is ready.
But the language throughout this lates update clearly points in a single direction. A studio talking about bug counts, live fixes at a trade show, and a feature set it calls largely complete is a studio that thinks the finish line is close. None of that is a release announcement, and I would not treat it as one. But by the look of things, this A220 may finally be getting ready to leave the hangar and into simmers’ hands.
Synaptic’s full development update is on the iniBuilds forum.
