X-Plane 12
Laminar Research Rolls Out X-Plane 12.3.1 Beta with FMS Speed Predictions and Enhanced Wake Turbulence
By James Whitfield · · 2 min read
The latest public beta brings refined VNAV speed predictions for the default FMS, improved wake turbulence modeling, and fixes for RNP AR approach handling. Laminar says the update targets airline-style operations and study-level fidelity.
Laminar Research has released X-Plane 12.3.1b1 to public beta, delivering a slate of avionics and flight-model refinements aimed squarely at the airliner crowd. The headline item is an overhauled speed prediction engine within the default FMS, which now computes VNAV descent paths using updated drag curves and wind interpolation. Early testers report that descent planning on complex STARs—such as the ROBUC3 into KBOS—now aligns more closely with real-world FMS behavior, reducing the need for speedbrake intervention.
Wake turbulence modeling has also seen a significant update. The new system simulates wake vortex decay based on aircraft weight, wingspan, and atmospheric stability, with lateral and vertical displacement effects. Pilots flying behind heavy types on final approach will notice more realistic roll perturbations, particularly in crosswind conditions. Laminar notes that the model is still tunable via Plane Maker for developers who wish to customize wake behavior.
On the navigation side, RNP AR approach handling has been corrected, fixing an issue where LNAV would overshoot tight radius-to-fix legs. Additionally, the G1000 and GNS 530 now properly display vertical deviation on LPV approaches. The beta is available via the X-Plane installer’s beta channel. As always, Laminar recommends backing up your current installation and reporting discrepancies through the official bug reporter. Given the scope of changes, a stable release is expected in late October.
Tags: Laminar Research, X-Plane 12, FMS, VNAV, Beta