X-Plane 12.1.0 Beta 1 is finally here. Looking at the lengthy Release Notes, there are quite a few feature improvements. Below is a translation of excerpts that I am particularly interested in.

General Updates

• Clouds are now blended at the voxel level rather than the METAR level, fixing issues with pyramids, cubes, and other distinct shapes.
• Weather near METAR stations uses softened Voronoi diagrams for blending instead of the lever method, resulting in METAR conditions at airports that are closer to reality.
• Refactored internal code to streamline the interaction between envelopes, moments, and simulation.
• The downloader has been rewritten to download current weather faster.
• Enabled new weather servers that make METAR data more resilient and allow for debugging of past weather via replay support tags.

World Space Cloud Shadows

• This change moves cloud shadows from STR space to world space, similar to regular shadows. This decouples cloud shadows from the weather domain. Registration between cloud shadows and the world has been improved.

Turbulence

• Improved the turbulence system to provide a smoother experience, particularly around cumulus clouds.

Icing

• Updated icing effects for multiple aircraft (A330, B737, C90, and Citation X).
• Icing based on surface normals and wind direction. Added directional icing even without heat sources.
• Freezing rain and ice are now present, and some random thermal inversions will also cause icing.
• Added support for overlapping heat sources.

Controller Support

• Full controller protocol support
• Weather system supports drawing thunderstorm cells via controllers

Bug Fixes

• IMC presets have stratus clouds to reduce turbulence during IMC training
• Cloud bases thicken faster for a better transition to IMC
• Fixed a bug where cloud bases were too high in low ceiling weather conditions
• Multiple METAR parsing fixes
• Weather maps display GRIB grid data more accurately
• TCP connections support IPv4 on dual-stack machines (required for controller support)
• Fixed cloud base errors
• Fixed cloud bases to be tighter and resolved missing bottom voxels. This improves cloud base conditions to some extent

Graphics

Core Engine

• FXAA is always enabled when MSAA is selected
• Use Coverage to Alpha on alpha-tested surfaces when MSAA is on for higher quality
• MSAA resolve is now scene-referenced for better visual effects
• Depth of Field
• Exposed RCAS options in the Settings menu
• Notification in the settings menu when textures are downgraded due to VRAM pressure
• VRAM improvements as more data is in charts, allowing charts to allocate memory better
• Smooth shadows
• Water surface cloud shadows
• Significantly improved rendering chart re-baking times
• Improved cloud shadow quality and atmospheric scattering quality

Lightning

• Added subtle color to lightning
• Made distant lightning slightly fainter
• Made nearby lightning slightly thicker
• Made the starting segments of lightning fade out gradually
• Lightning overflow lighting range was too large
• Improved sound distance response

New Particle Effects

• Particle effect system supports particles appearing upon contact with the ground
• Particle effect editor now supports copy/paste functionality
• New data references to support particle effects
• New built-in effects include JATO (Jet-Assisted Take Off), fire fighting, water bombing, ground scarring, and rotor wash
• Override option in ACF to opt out of the new effects if desired

Water

• Fixed water turbidity model: water is no longer always completely transparent.
• Default water color and clarity vary by location (e.g., water near SABE is opaque and turbid, while water near MBPV is near clear turquoise).
• Cloud shadows are more distinct on water surfaces.
• Fixed a bug with orthophoto scenery packages using water.

Autogen

• Improved building autogen for high-density European residential areas.
• Improved the system for generating parked aircraft at airports. The system will always select the largest possible aircraft based on the parking spot size.

Systems and Avionics

G1000 Enhancements

Startup Splash Screen

• Displays the navigation database expiration date and X-Plane version (and thus the X-Plane global airport version)

Navigation Page

• Default navigation map: Added options for ADS-B traffic symbols and displaying METARs
• Traffic map: Displays ADS-B traffic targets with precise speed vectors (unlike the old TCAS, we know exactly where other aircraft are heading) as well as flight ID/tail numbers. Traffic can be filtered to normal altitude range (default), Above (for climb), Below (for descent), and Unrestricted (to see traffic at all altitudes)
• Storm detection: Displays lightning activity around the aircraft via passive detection of electrical discharge
• Data link weather: Displays in-flight weather received via ADS-B or XM satellite, including NEXRAD radar maps, lightning, cloud cover, winds aloft, and METARs
• Terrain: Shows upcoming terrain warnings

Waypoint Page (WPT Page)

• Airports: Displays information for any airport. Retrieves decoded METAR reports for any airport (received via ADS-B or XM in reality)
• Intersections: Displays information for any intersection, including its nearest VOR
• NDB, VOR: Displays information for any navigation aid, including its nearest airport

Auxiliary Page (AUX Page)

• GPS Status: Displays current GPS accuracy and GPS status (whether DIFF NAV is available). SBAS can be deselected for training purposes.
• LRU System Status: Displays the status of all G1000 LRUs (Line Replaceable Units) and aids in fault detection. Allows verification of the navigation database cycle.

Reversion Mode

• On a cold start, the PFD stays in reversion mode until the pilot acknowledges the database on the MFD

New Datarefs

• Added new datarefs to query active pages and overlays

Flap System Additions

Johnson Bar Flaps

The Piper PA-28 features one of the simplest flap systems in the world. It is entirely manual, requires no electric motor, and gives direct control of the flaps to the pilot. The Johnson bar between the front seats connects directly to the flaps, allowing the pilot to actuate them as quickly or slowly as desired, and even hold them at an angle slightly beyond the last detent while keeping a hand on the bar. Fine-tuning flaps is a proven technique often used by commercial pilot students during power-off 180-degree landings.

Therefore, X-Plane now features a new manual flap system. You can activate it in Plane Maker by checking the “Johnson bar direct link” option in the “Control Geometry” section, where you can set flap detents.

If this option is active, the flap handle and flap deployment are directly linked with some new behaviors, but all use existing commands:

• If you tap the flap toggle command, you will see the flaps move immediately (quick pull of the handle)
• If you hold the command, you will see the handle move smoothly (following the movement time entered in Plane Maker)

In this way, you can precisely adjust the flaps. For example, by pressing the “2” key three times quickly, you can pull the handle up in short bursts (click, click, click). Holding the “2” key will smoothly raise the handle to the next detent. Release and hold again to raise to the next.

• If flaps are fully deployed, holding “2” can extend flaps to 110%. Once released, they will immediately return.
• If there is a joystick axis assigned to flaps, it will follow the joystick axis directly, without delay.
• Full extension of the joystick axis corresponds to 110% extension.
• All datarefs for the flap handle now accept input in the 0-1.1 range, and the handle syncs immediately with the flaps, without delay.

Select Flaps

Select Flaps is a system applied to McDonnell Douglas aircraft that allows you to select any flap extension position for takeoff, from fully retracted to landing configuration. Simply dial the selector to the desired flap extension, then set the flap handle to the “Select Flaps” position, and the flaps will move to the pre-selected extension.

When Select Flaps is chosen in Plane Maker, one flap detent can be designated as the “Select Flaps” detent. By default, its flap extension will be halfway between the previous detent and the next one, but the pilot can pre-set the desired extension for takeoff. The desired setting is pre-selected via the dataref “sim/cockpit2/controls/flap_dial_a_flap”, then placing the flap lever in the “Select Flaps” detent causes the flaps to extend to the selected setting.

S-Tec ST-360

The S-Tec autopilot system has been expanded to include the ST-360 Altitude Preselect and Alerter, working with the System Fifty-Five autopilot. This small altitude alerter has its own barometric adjustment, independent of the pilot’s Altimeter, so the pilot needs to remember to input the Altimeter setting in both places, or the autopilot will Level Flight at the wrong altitude. The barometric adjustment on the ST-360 is only in 1/10ths of an inch (whereas the pilot’s Altimeter is in 1/100ths), so the Level Flight altitude will only be approximately accurate. The pilot is expected to make fine adjustments on the autopilot itself (the knob on the S-Tec55 adjusts altitude hold in 20-foot increments).

Approach Preview

Approach Preview is a feature found on some Electronic Horizontal Situation Indicators (HSI) that allows you to view both lateral and vertical deviation simultaneously and enables the autopilot to intercept one deviation while maintaining the other. This functionality is most commonly used when intercepting an ILS Approach during GPS navigation. In this scenario, the HSI will select the GPS source to fly the transition route. The autopilot will follow GPS navigation in NAV mode. Then, the ILS is tuned, and the corresponding NAV receiver is selected for preview using the dataref “sim/cockpit2/radios/actuators/HSI_preview_source_select_pilot”.

An EFIS with preview capability (such as the one on the Citation X) will display both GPS and ILS simultaneously.

After arming the approach mode on the autopilot, the autopilot will wait for the lateral signal of the preview source to intercept. Once the lateral deviation (e.g., the ILS in our example) starts to move, the autopilot will automatically switch from GPS navigation to the preview source without pilot intervention. The autopilot seamlessly transitions from GPS navigation to VLOC navigation, and the HSI will stop displaying the preview and switch to the new active source.

Helicopter Electric Clutch

The helicopter clutch used to connect piston engines to the rotor system is now an electrical component. This means its motor can be assigned to a bus and set to a current draw, relying on electricity to operate.

The tachometer instruments can also now be electrically powered, displaying correct failure modes.

Single-Lever Turboprop Control

Turboprop engines can combine propeller governor control and idle/fuel control into a single lever known as a condition lever. In the upper range, it acts as a propeller controller, setting the propeller governor’s desired RPM. In the lower range, it first feathers the propeller and eventually shuts off the engine’s fuel supply.

To create such a single-lever control in Plane Maker, check the “Feather at prop control min position” and “Cut fuel at prop control min position” options.

In X-Plane, the condition lever can be assigned as “Prop lever with feather and cutoff” in the joystick curves screen. This allows for precise setting of the feather and cutoff toggle points to match specific hardware.

GPS and ESP Updates

GPS Coupling Setting a nav flag means GPS is providing deviation and can be coupled.

Setting a vertical flag means the vertical signal is valid and can be coupled. Added GPS2 OBS datarefs. Nav ID datarefs are now writable (provided override_gps is enabled). Added some writable NAV-radio and GPS datarefs in cockpit2/. These were already writable in sim/cockpit (with override_navneedles or override_gps enabled), so there is no reason for them not to be writable in sim/cockpit2/.

Autopilot coupling allows the autopilot to couple directly to any GPS that has the TO/FROM flag set to TO or FROM.

ESP Feel Optimization Optimized ESP feel based on real aircraft flight testing. In the SR-22, the wing auto-leveling should be smoother, rather than a sudden “jolt” that you can easily overcome just like in the real aircraft.

Garmin ESP Features Can be enabled or disabled per ACF in Plane-Maker. Authors can specify which ESP protections Garmin provides via checkboxes on the Autopilot screen in Plane-Maker, and toggle them on or off as needed.

Datarefs

New Datarefs for Autobrake Deceleration Rate Autobrake deceleration is now available as an array dataref to preset the desired deceleration (in Gs) for each setting.

Datarefs for Manual Override (MOR) Throttle Added datarefs for manual override throttle.

Dataref Description Updates

Dataref description updates Updated the Datarefs.txt file, adding descriptions for fuel pump datarefs.

FADEC no longer writes N1 arc This has no effect on observable behavior—-the value was never readable as it was immediately overwritten. The value people might be interested in (the N1 limit achievable at full throttle) is already available as the dataref sim/cockpit2/engine/actuators/N1_target_bug.