Active Sky for P3Dv4

ASP4 is for the Prepar3D v4 Simulator Platform

Active Sky for Prepar3D v4 (ASP4) represents 17 years of weather simulation engine development!  Building on the Active Sky weather engine experience, ASP4 brings a new 64-bit ASConnect simulator interface, 64-bit XGauge, new Air Effect enhancements, new Visibility Depiction enhancements and more, all specifically designed for Prepar3D v4!

In-Cloud Motion EffectsWeather Scenarios SystemAirborne Weather RadarP3D Visibility Smoothing and Volumetric Fog IntegrationNavigraph Data Integration, Map-based Custom Weather Editing System, Universal Web Companion AppMapping System and a High-Latitude Cloud Squeeze Fix are just a few of the advanced features included in the core Active Sky platform.

ASP4 also incorporates full integration with Active Sky Cloud Art (ASCA), our graphics add-on for both FSX and P3D.  ASCA includes cloud texturessky textures, and 3D cloud models to transform your skies, while also incorporated Real-Time Dynamic Cloud and Sky Textures!  This enables realistic weather-influenced texture variation that reloads throughout your flight without needing to shut down and restart your simulator.  You can use any graphics add-on(s) with ASP45, but dynamic texture reloads require the ASP4+ASCA combination.

If you are an AS16 for P3D user who wants to install ASP4, please download from our downloads page ( and use your AS16 for P3D key!


AS16 for P3D users receive a free copy of ASP4.  Likewise, ASP4 users receive a free copy of AS16 for P3D.  A single license key works for both independent products.  To download ASP4 or AS16 for P3D, visit our downloads page.

ASP4 is available in full or upgrade versions.  Eligible upgrade products are Active Sky Evolution (ASE), Active Sky 2012 (AS2012), Active Sky Next (ASN), and AS16 for FSX (Cross Platform Upgrade) that were purchased through our standard re-sellers (Steam/ASN:SE purchases are not eligible for upgrade).  If you have purchased a license for any of the eligible products, and have a license key for that eligible product, you qualify to purchase the upgrade version at a discount.  Please see the re-seller’s product pages for further instructions and details regarding upgrades.

Active Sky Products are offered via several authorized re-sellers.  Authorized re-sellers include: SimMarket, Just Flight, Aerosoft, Flight1, FSPS Store and Store.  Notice:  Purchasing from an unauthorized re-seller may result in modified pirate software and/or malware and will result in that product/license being deactivated and unable to be used.  Please purchase only through the authorized re-sellers.

Please click on your desired preferred re-seller:



*** Resellers may offer different base currency, policies and effective pricing.  Check with your re-seller for details.  All prices subject to change. ***


Feature Highlights
Additional Features
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Frequently Asked Questions


New ASP4 Features

Redesigned 64-bit ASConnect simulator interface with tight P3Dv4 integration

Updated XGauge radar and weather display gauge, now in 64-bit

New Air Effect Enhancements including Low-Interval Smoothing for a more organic and realistic feel to updrafts, downdrafts, thermals, gusts, sheer, turbulence and microbursts

New Visibility Depiction Enhancements including new low and high altitude visibility horizon distance adjustment options

New Active Runway Data, showing the active runway in use based on current wind conditions via Map pop-ups, Conditions Screen METAR text and Briefing text

General improvements in performance and stability throughout

Incorporates all of Active Sky weather engine previous product technologies including highly-realistic global weather data integration, advanced radar and precipitation simulation, cloud position awareness and synchronized cloud-based effects, advanced air effects, microburst simulation, wake turbulence simulation, and much, much more


Core Features introduced in AS16

In-Cloud Motion Effects

Feel the speed of motion while flying through clouds

XGauge WX + Radar

Enhanced weather gauge with included realistic airborne radar modeXGAUGE

Weather Scenarios System

Challenge yourself with several scenarios including a Microburst Encounter, Gusting Winds, Wake Turbulence, and more


High-Latitude Cloud Squeeze Fix

Fly high-latitude areas without stretched clouds



Map-Based Custom Weather Editing System

We’ve re-designed custom weather editing and provided a new easy map-based custom weather area manager and weather setting wizard


ASCA Integration for Real-Time Texture Dynamics

ASP4 works with any texture/graphics add-ons (including default graphics), but when combined with ASCA, real-time texture dynamics and automatic wx-influenced selections are enabled

Web Companion App

Remotely view and control weather using any device on your local network with new webserver/browser technology

active sky weather image

Map System

Vector Background Options and Background Overlays


NAVIGRAPH Data Integration

Airports, Navaids and Fixes now provided by Navigraph!  A complimentary expired database is included with ASP4, and regular AIRAC cycle updates are available with a Navigraph subscription



Award-Winning Active Sky Weather Simulation Engine – Enhanced Further!

We’ve been enhancing and growing Active Sky since 2000, and this new version expands our weather engine even further than ever before

Enhanced Thunderstorm Effects

Thunderstorms are now very dangerous, as they are in the real world, and require avoidance, in most cases, to ensure safe and successful completion of your flights – Flying into heavy cells can result in loss of aircraft control and even airframe stress overload

Performance-Focused Design

We’ve taken the previous codebase for Active Sky and re-factored it, tuned it, and re-designed many core areas for increased performance and usability

User Interface Improvements

We’ve incorporated user feedback and made dozens and dozens of improvements throughout the entire UI

Hybrid Weather Depiction Technology

AS16 uses multiple integration and depiction methods to provide realistic, smooth and correct weather and ambient conditions at all times, while also providing full cloud position awareness to enable advanced cloud-synchronized radar, precipitation and air effects

High-Fidelity Data Resolution and Coverage

Active Sky 16 includes enhanced global gridded weather data, global sigmets and airmets, global surface data and global aloft data for much improved realism and coverage for all kinds of conditions in all areas without relying strictly on METAR reports

High-Fidelity Air Effects

Wake Turbulence, Microbursts, Downdrafts, Updrafts, Terrain-influenced Drafts, Thermals and more!

Smooth Transitions

Cloud formations, wind, temperature, visibility and every other aspect of your weather is smoothed, transitioned and interpolated for the ultimate in realism

Private Server Network

AS16 utilizes the high-performance and high-availability HiFi DataNet weather network with multiple servers in multiple regions around the world, providing high-resolution weather data and historical data archives for the past 2 years

Online Historical Data with Playback

Fly in weather at any date/time up to 2 years in the past and have weather update realistically throughout your flight according to hourly-archived conditions

Active Sky API

AS16 utilizes an extended version of the Active Sky API, allowing 3rd party developers to integrate and take advantage of advanced radar, icing, wind shear, weather data and weather controlling extensibility

Much More!

AS16’s full feature list is too numerous to list here, but we invite you to TRY ASP4 for yourself and experience all it has to offer!


Windows 7, 8.1, 10 or later

Prepar3D v4

2GHZ processor or better

2GB RAM or better

1GB available hard drive space

Minimum monitor resolution to access all user interface features: 1024×768

Sound device (for sound and voice features)

This is an ONLINE product that requires an active connection for proper functionality and features – it cannot be used offline

This product is licensed PER COMPUTER and requires a valid license for each active computer installation.  Using the product on multiple PCs by a single or multiple users will result in automatic deactivation.  10 computer moves/re-activations are included automatically.  Subsequent re-activations will require contacting our support department, providing order verification documentation, and confirming proper and valid use per the license agreement.


3.0GHZ Processor or better

4GB RAM or better

Broadband high-speed internet connection

1280×800 or better resolution



All screenshots on this page are unedited,  brought straight from the simulator, with only a frame border applied for presentation. What you see is what you get!

Note that these shots are a compilation from ASP4, AS16 for P3D annd AS16 for FSX on various platforms including P3Dv4, P3Dv3, FSX and FSX:SE.



Will PMDG 737/777, iFly 737, or other aircraft add-ons using ASN Radar API continue to work with ASP4?

Most add-on aircraft developers using AS radar integration have already updated their products with the new 64-bit ASP4 API changes.  Please check with your aircraft developer for details.

I have AS16 for P3D, how do I upgrade?

ASP4 is a free upgrade for AS16 for P3D users.  Simply download ASP4 from our downloads page and use your previously-issued AS16 for P3D key.

Will ASN be upgraded to P3Dv4 compatibility?

No, this is not possible due to technology differences on the 64-bit platform which required a brand new product variant with specific P3Dv4 integration, which was built on the AS16 for P3D code base.   ASN users can take advantage of our upgrade program.

Will I get a discount for ASP4 as I am a previous ASN, AS2012 or ASE Customer?

Yes!  We have an upgrade product offered at our resellers which provides a substantial discount.

What about an upgrade for AS16 for FSX users?

Yes, using the same upgrade product, cross-platform AS16 for FSX -> ASP4 is also supported/eligible.

Can I run P3Dv3 and P3Dv4 at the same time?

Yes, using AS16 for P3D (v3) and ASP4 (v4) separately installed products, using the same license key.  You can download ASP4 or AS16 for P3D from our downloads page.

Do I have to use ASCA with ASP4?

No, ASP4 is compatible with all graphics including default graphics.  ASP4 can be combined with ASCA for real-time dynamic texture reloads, but this feature is not required.  Feel free to use your favorite graphics add-ons with ASP4 just as you have been able to with ASN!


Feature Highlights
Additional Features
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Release Status
Frequently Asked Questions