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XP X-15-1 v1

XP X-15-1 v1


Our X-15-1 v1 addon contains two variations of the X-15-1 with the interim XLR-11 rocket engines and two variations with the million-horsepower XLR-99 rocket engine, designed for Microsoft® Flight Simulator 2004 (compatible with FSX and Prepar3D®).

The addon includes two detailed exterior models, four fully functional 3D virtual cockpits, 2D panels, a flight model to simulate rocket powered high-speed and high-altitude flight, and two flight manuals.

Please note that this addon is a legacy product offered for a limited time and for which we can no longer offer technical support.


A Classic Addon Available for Download for a Limited Time

Over the years, some of our products have become legacy due to the constant evolution of the simulation platforms or because they are being replaced by better, up-to-date products with much more features. By popular demand and for a limited time, we are now please to offer these products a very special price.

Please note that the X-15-1 v1 addon is a legacy product for which we can no longer offer technical support. It is offered to collectors as is. For an upgraded X-15 experience, please consider our X-15A-2 SE v2.0 for Prepar3D®, FSX and FSX Steam®.

Faster than a Speeding Bullet!

The legendary North American X-15 was a single-place research airplane designed to obtain data on flight at extremely high altitudes and speeds. Three X-15 aircraft were built to demonstrate the ability of pilots to fly rocket-powered airplanes out of the earth’s atmosphere and back to precision landing.

The X-15-1 (AF56-6670) was rolled out in October 1958, and successfully completed its first powered flight in January 1960, after a series of captive and glide flights. The No. 1 aircraft completed 81 missions during the nine-year X-15 research program. Legendary test pilot Scott Crossfield was the first to fly the X-15-1 in the spring of 1959 while NASA pilot Bill Dana flew the aircraft for the last time in October 1968.

The Xtreme Prototypes X-15-1 addon contains two variations of the X-15-1 with the interim XLR-11 rocket engines and two variations with the million-horsepower XLR-99 rocket engine.

The two detailed exterior models feature more than 300 parts and 60 animations. The four fully functional 3D virtual cockpits and 2D panels contain over 900 parts and 240 custom gauges and systems (all rocket aircraft systems present in the real X-15 are simulated). A custom X-15 flight model was designed to simulate rocket powered high-speed and high-altitude flight in the simulator.

This addon will allow X-15 fans to fly at altitudes of over 300,000 feet (in FSX) at more than four times the speed of sound (or the maximum speed that can be attained in the simulator) and to simulate almost every step and procedure required in a typical X-15 research mission.

Download the Manual

Download the full 22-page virtual cockpit manual
(13 MB, PDF format)

Download the full 110-page basic utility flight manual
(18 MB, PDF format)

Manuals are updated frequently, make sure you have the latest version.

What you Need to Know

  • You must accept the end-user license agreement before you can download, install and use this software.
  • Please read Minimum System Requirements, below.

This legacy addon was originally designed for FS2004, but is compatible with FSX and Prepar3D®. Boxed FSX requires SP2 with Acceleration Expansion Pack (FSX Gold fully installed). No FSX Steam® installer is provided. Installation in FSX Steam® requires changing the path to your FSX Steam® folder during installation. This addon can be installed in Prepar3D® but has not been thoroughly tested on this platform. No Prepar3D® installer is provided. Installation in Prepar3D® requires changing the path to your Prepar3D® folder during setup.

IMPORTANT: Xtreme Prototypes addons are complex and require better graphics cards and more processing power and RAM than other more conventional addons. Increased performance will be noticed on more powerful systems. Before purchasing this product, make sure you have the minimum system requirements or better. For obvious reasons, downloads are not refundable.

  • Flight Simulation Platform: Microsoft® Flight Simulator 2004 (FS9) or Flight Simulator X with Service Pack 2 (FSX Acceleration Expansion Pack or FSX Gold optional). Compatible with Lockheed Martin Prepar3D® (please read note below).
  • Operating System: Windows® 10/8.1/8/7/Vista/XP SP2 32-bit (64-bit recommended), depending on your simulator's requirements*.
  • Processor: Dual Core 3.0 GHz (Quad Core 3.0 GHz or better recommended)
  • Hard Drive Space: Downloaded ZIP file size approx. 300 MB, addon size approx. 500 MB when installed*
  • Graphics Card: A high-end graphics card with at least 8 GB GDDR5 or better is highly recommended*. Installing this addon in Prepar3D® requires a DirectX® 11-compatible graphics card*. Make sure you have the latest driver for your operating system.
  • Graphics: DirectX® 12, 11, 10 or 9 (depending on your simulator's requirements)*
  • Other: Wheel mouse, joystick (pedals optional), sound card and speakers, Adobe® Acrobat® Reader. A wheel mouse is required to actuate 3-position switches and some knobs.

*: Refer to your simulator's documentation for more information.

Note for FSX/FSX Steam® users with DirectX® 10 or later : This addon was designed for FS2004 but is compatible with FSX SP2. However, the current version of the software does not support DirectX® 10 or later. The "DirectX® 10 preview" option box and the "Light bloom" option box in the FSX Display Settings page must be unchecked for proper aircraft display.

Note for Prepar3D® users (all versions): We have not thoroughly tested this native FS2004 addon in Lockheed Martin® Prepar3D®. However, we have been able to fly our X-15-1 addon in Prepar3D®. Please note that there is no installer for Prepar3D® available for this addon. To install the addon in Prepar3D®, simply change the path to your Prepar3D® folder during installation. Select the "FSX with Acceleration Expansion Pack" option if asked.

Note for FSX Steam® users: Please note that FSX Steam® Edition is installed in a different way to the boxed version and occupies a different location on your computer. There is no FSX Steam® special installer provided with this addon. To install the addon in FSX Steam® Edition, simply change the path to your FSX Steam® folder during installation. Select the "FSX with Acceleration Expansion Pack" option if asked.

General Features

Two versions of the X-15-1 aircraft (s/n AF56-6670) with the XLR-11 rocket engines (limited-mission configuration):

  • "Clean" rollout version with the NACA vane-type boom nose and the original (XLR-11) black panel
  • "Dirty" version with the NACA vane-type boom nose and the original (XLR-11) black panel

Two versions of the X-15-1 aircraft (s/n AF56-6670) with the XLR-99 rocket engine (design-mission configuration):

  • "Dirty" version with the NACA/Nortronics ball nose and the original (XLR-99) black panel
  • "Dirty" version with the NACA/Nortronics ball nose, wing-tip pods, tail-cone box and the (XLR-99) light blue-gray panel

Flight Model Features

Custom X-15 flight model to simulate rocket-powered high-speed and high-altitude flight on your simulation platform:

  • Two Reaction Motors XLR-11, 5900-pound four-chambered liquid-fuel turbo-rocket engines (or) One Reaction Motors XLR-99, "throttable" 60,000-pound liquid-fuel turbo-rocket engine
  • Supersonic flight up to the maximum speed attainable in the simulator (approx. Mach 4.65)
  • High-altitude flight up to 354,200 feet in FSX (100,000 feet in FS2004)
  • Fictitious ground takeoff or high-altitude launch (like the real aircraft)
  • Good maneuverability at supersonic speeds
  • Excellent gliding capabilities

X-15 Rocket Aircraft Systems

The following aircraft systems are simulated to conform as closely as possible to the operation of the real aircraft, within the present limitations and capabilities of the available simulation platforms:

  • XLR-11 power plant system and control
  • XLR-99 power plant system and control
  • Fictitious service panel system for external power and aircraft refueling (water-alcohol or ammonia, liquid oxygen, hydrogen peroxide, nitrogen and helium gas, liquid nitrogen)
  • Custom X-15 fuel management system for the three different types of propellants and gases, like in the real-world X-15 rocket plane
  • Fuel system
  • LOX system
  • Hydrogen peroxide system
  • Nitrogen system
  • Helium system
  • Engine propellant pressurization and control system
  • Engine turbopump system
  • Engine ignition control system
  • Electrical distribution and control system with APUs, generators, emergency battery and an external power source
  • Hydraulic system
  • Temperature control system
  • Custom rocket aircraft instruments, controls and gauges

Aircraft Exterior 3D Model Features

  • Native FS2004 3D models
  • Highly detailed models based on archive material, with more than 300 parts and 60 animations
  • Reflective textures
  • Unique markings and liveries (on each aircraft)
  • Dynamic frost texture on fuselage (around the liquid oxygen tank when filled)
  • Movable aerodynamic control surfaces:
    • Differential horizontal stabilizer
    • Vertical stabilizers with movable and fixed sections and a jettisonable ventral rudder
    • Flaps
    • Extendable upper and lower split-flap speed brakes
  • Landing skids and front gear ("steerable")
  • Movable canopy
  • Cockpit details with astronaut/pilot and animated sticks and levers
  • Experimental equipment on some airplanes (wing-tip pods, tail-cone box, etc.)

Aircraft Interior 3D Model Features

  • Four fully functional and highly detailed 3D virtual cockpits (black or blue) with over 900 parts and 200 animated gauges, switches, levers, light indicators and flight instruments with “tooltips”
  • Advanced instrument panels:
    • Main panel with two side panels
    • Left console
    • Right console
    • Center pedestal
  • Side controls
  • Three control sticks, handles and levers
  • Cockpit spotlights (VC and exterior model)
  • “Invisible canopy” mode to fly the X-15 without the clamshell-type canopy on for more visibility and a spectacular view from the VC

Aircraft 2D Panel Features

  • Advanced X-15 black (2D) main instrument panels (XLR-11 or XLR-99 engines)
  • Advanced X-15 light blue-gray (2D) main instrument panel (XLR-99 engine)
  • Service panel
  • Left white console panel with "vent, pressurize, jettison" lever and flaps switch
  • Throttle (or thrust selector switches on the XLR-11-equipped aircraft) and speed brake panel
  • Left side panel
  • Right side panel
  • Radio panel (ADF panel on some aircraft)
  • RAS panel (on some aircraft)
  • Center pedestal with research instrumentation and stability augmentation system panels
  • 240 fully functional custom integrated systems and gauges with "tooltips"
  • Multiple side views (FSX)

Visual Effects

Custom X-15-specific animated visual effects, some with sound (FSX), including:

  • Rocket engine combustion flames and shockwave effects
  • Engine first and/or second stage igniter effects
  • Rocket engine smoke and contrail effects
  • Propellant jettison effects (fuel, LOX and H2O2)
  • Engine turbopump exhaust effect
  • APU exhaust effects
  • Engine precool and prime effects
  • N2/LOX bleed effect
  • Condensation and vapor effect around the cold LOX tank when filled
  • VC lights
  • Wing vortices and vapor trails

Sound Effects

  • X-15 custom sound sets


  • Automatic rocket engine ignition sequence button
  • Ten camera definitions or views (FSX only), some of them corresponding to the real-world X-15 external bug-eye camera views
  • Twelve saved flights based on X-15 historical missions to simulate a high-altitude launch or a takeoff from the ground
  • X-15-1 aircraft kneeboard reference tabs and check list
  • A comprehensive 100-page basic user manual and a 20-page VC manual inspired from the original X-15 utility flight manuals, in a printable PDF format (English and French language versions)

About our three X-15 v1.x addons combined:

Chris Frishmuth, PC Pilot Magazine:
"Pushing the limits! The most exotic aircraft I've yet flown in Flight Simulator. The attention to systems detail and other areas of the package are admirable. For a truly fast-paced and historical ride, the Xtreme Prototypes X-15 cannot be beaten!"

Mark Kolo, Avsim.com:
"Xtreme Prototypes did a spectacular job creating effects for both the XLR-11 and XLR-99 engines on the X-15. I have to say, that the first time that I started the XLR-99 motor and watched it spit out a massive exhaust flame, I thought that I was dreaming. Overall, the effects are of the highest quality that I have seen, and really complete the X-15 package."

Emmanuel Blanchard, Micro Simulateur Magazine:
"when stunning graphics combine with the realism of the flight procedures, we get the ideal product [X-15] for advanced test pilots!"

Mark Kolo, Avsim.com:
"Unique product, well executed model, VC, and effects. I would highly recommend it [the X-15] to any virtual pilot who has an interest in the X-planes or other high performance aircraft."

J. Fiedler, X-15 fan:
"My face hurts right now because of all of the smiling I have been doing. I have had such fun in the last hour flying the X-15. My sincere thanks Gentlemen."

S. Blair, X-15 fan:
"Just thought I'd drop a line to say your X-15-3 package is first rate all the way. The documentation is the best I've ever seen. Whoever assembled the manual did a knockout job. The aircraft flies very well with no technical hitches at all."

M. Watkinson, X-15 fan:
"It really is an awesome simulation of the X-15 series! Cheers."

J. Bordenave, X-15 fan:
"No bugs, thank you for this superb [X-15] addon."

D. Hall, X-15 fan:
"What a fantastic [X-15] addon. It truly is one of my favorite addons that I have tried."

Listed below are the latest available patches for your Xtreme Prototypes X-15-1 v1.x addon - for registered users only. To download these files, please login to your Xtreme Prototypes online account.

(2008-08-16) Version 1.1 of the X-15-1 for Flight Simulator FS2004 & FSX with virtual cockpits (compatible with FSX with Acceleration Expansion Pack and FSX Gold). If you have purchased the download version of this software after April 16, 2008, you do not need to download this upgrade. Free for registered users of version 1.0.