[VSKYLABS Newsletter] issued 9th January 2026
This newsletter explores the VSKYLABS 'Test-Pilot': Rutan Model-158 PT-6 Project, a speculative “what-if” evolution of Burt Rutan’s original Model-158 concept. Rooted in the real aircraft’s design philosophy and mission intent, the project examines how the airframe might have evolved had a PT6A turboprop been considered as an alternative powerplant.
The article outlines the historical background of the Model-158, the reasoning behind the PT6 adaptation, and the engineering challenges involved in translating this concept into a physically grounded X-Plane 12 simulation, from performance modeling and systems integration to handling qualities and operational character.
*This briefing was originally issued as a VSKYLABS Newsletter on 26 January 2024.
The Rutan Model-158 'What-if' PT6A Variant for X-Plane 12!
This newsletter is dedicated for a very unique aircraft introduction, the Rutan Model-158 - the 'Pond Racer'.
VSKYLABS developed an enhanced, fictional (yet plausible) variant of the Rutan Model-158 for X-Plane flight simulator. Unlike the actual Pond-Racer, which was designed as a racing aircraft, the VSKYLABS Rutan Model-158 was re-designed as a capable high-speed cross-country aircraft, powered by twin PT6A-28 turboprop engines, equipped with comprehensive systems and avionics to extend its usability.
*The VSKYLABS development of the Rutan Model-158 project for X-Plane flight simulator was acknowledged and approved by Mr. Burt Rutan. However, it is an independent VSKYLABS project which is not related, affiliated and/or endorsed with/by Mr. Burt Rutan.
In this newsletter, we will go through a short introduction of the real Pond-Racer aircraft, its main design features and a short deeper analysis of the aircraft. Then, we will proceed with a short introduction of the VSKYLABS Rutan Model-158 PT6A variant.
We hope that you will enjoy the ride!
Let's begin!
Pond Racer Brief History (real-world aircraft)
The Rutan Model-158 'Pond-Racer' was a twin-engine racing aircraft, developed by Burt Rutan (at his company 'Scaled Composites'), for Bob Pond (1924-2007), a honorable aviator and inventor, to be flown at the Reno Air Races back in the early 90's.
Bob Pond envisioned modern aircraft racers competing at Reno, replacing the use of warbirds. The "Pond-Racer" was a twin-boom all-composite (graphite) aircraft, which was powered by two Electramotive automobile engines capable of 1,000 hp each.
The Pond Racer made its first public appearance at the Reno Air Races in 1991, but dropped out due to mechanical problems. On September 14th 1993, during qualifying, the Pond Racer, which was piloted by Rick Bricket, crashed following engine failure, killing the pilot. The crash of the Pond-Racer ended its development.
Here are some details regarding the actual, real-world 'Pond-Racer' aircraft.
Pond Racer General Specifications:
Wingspan: 25.4 ft
Fuselage length: 16 ft
Engine Boom length: 20 ft
Engine Nacelle diameter: 26"
Gross weight: 4150 lbs.
Propulsion: Two counter-rotating, modified Hartzell propellers powered by two Nissan VG-30 automotive racing engines, designed to produce a 1,000 hp each (in practice, during test flights, engines configuration could hit only 600 hp each). Propellers were designed for 2,200 rpm.
General Performance:
The Pond Racer was designed to fly at Mach 0.7 (460 kts), and to be capable to carry out low-level 6.5-7 G's turn-performance. In practice, the Pond Racer qualifying speeds at the Reno Air Races was no more than 400 mph (~350 knots).
Main Design Features:
Twin-boom configuration, along with a central fuselage and butterfly vertical stabs tail section which was designed to increase directional stability. Burt Rutan's design approach to maximize performance was to design a streamlined aircraft to reduce drag. Fuselage and booms were designed with an extremely small cross-sections. The Pond Racer had a streamlined "bubble canopy" as well.
The Pond Racer was a tail-dragger configured aircraft, having its main landing gears retracted aft and into each boom.
The Pond Racer aerodynamic design of the wings and propellers was carried out by the experienced Aerodynamicist John Roncz, who has worked with Burt Rutan on many of his projects.
Fuel capacity was 84 gallons, allowing approximately 15 minutes of high-powered flight.
Dick Rutan made the first test flight of the Pond-Racer on March 22nd, 1991. Throughout its development and test flights phases, the Pond Racer was flown by four pilots: Dick Rutan, Mike Melvill, Rick Brickert and Steve Hinton.
Flying the (real) Pond Racer:
The Pond Racer was a heavy aircraft with a high wing loading. According to several flight reports, it was very stable and predictable in flight, and allowed an "easy ride" in non-calm, buffeting conditions.
Visibility was great *above the horizon*, meaning that visibility into the turn and aft/sideways was excellent. However, forward and *below the horizon* view were extremely bad, as the engines booms and wing configuration blocked down most of the lower section view due to the unique location of the cockpit.
Landing the Pond Racer was straight forward, based on several quoted impressions of Dick Rutan, stating that due to the Pond Racer configuration, the landing gears could be seen quite easily during the landing process, and touchdown, allowing a good sense of ground proximity.
Ground handling - The Pond Racer was not designed to power-taxi along the taxiway. Instead, a dolly was used to tow the aircraft straight to the takeoff position.
The cockpit was a tight-fit for the average pilot. Seating in the cockpit was in a glider-cockpit-like seating position, with almost no head-room for the helmet and a high cockpit floor. The tight cockpit environment was not designed for maximum pilot comfort, as the aircraft was designed for low flight duration in racing conditions.
The twin engine configuration consisted a very-close-to-the-centerline engines layout. This design aspect increased the aircraft performance, control and stability on a single-engine operation. Throughout its flight program, the pilots never throttled up the engines above 60% (of power output). There are several documentations of Dick Rutan comparing the flying qualities of the Pond Raced to that of a light Jet-Fighter.
VSKYLABS Rutan Model-158 Turboprop Variant - Design and Insights:
The VSKYLABS Rutan Model-158 Project introduces an enhanced yet plausible version of the Model-158 which incorporates a highly defined and robust PT6A-28 Turboprop propulsion simulation and other enhancements/modifications which are aimed to extend the aircraft usability beyond the basic "Stick and Throttle" Racing aircraft usage.
Enhancements included the PT6A-28 propulsion system implementation, along with a set of complementary systems, providing the needed instrumentation, environmental control, fuel system, navigation-aids and all-weather flying capabilities. The aircraft was fitted with a new fuel-system layout, pressurization, oxygen, pneumatic, electrical and avionics.
In order to stay truthful to the original design, all enhancements have been implemented on-top the SOLID CORE of the original Rutan Model-158 design, and with true-to-life, *plausible* design and integration of systems and equipment. The process involved the efforts to include the "Rutan design approach spirit", resulting with a kind of a home-built practical ‘flavor’.
The enhanced cockpit was designed on-top of the original Model-158 general cockpit layout. The goal was to create a 90's aircraft ‘look and feel’.
Several structural modifications had to be implemented into the original design, to allow the plausible implementation of the two PT6A-28 engines:
- A new and plausible intake design which had to be fitted in front of each engine boom elements.
- Landing gears bays of the original Model-158 are positioned in a way that allows a full PT6A intake design to fit in.
- A plausible Ice-vanes system (which is fully simulated in the VSKYLABS Rutan Model-158).
One of the fascinating insight from the thorough development and test flying process of the PT6A-28 powered VSKYLABS Model-158 in X-Plane Flight Simulator was that although the original aircraft design had significant restrictions with regards to fuel capacity, a plausible fuel tanks design layout allows approximately 1.5 hours of Long-Range-Cruise flight at true airspeed of more than 300 knots @ 25,000 feet. Added to this performance aspect is the phenomenal high rate of climb which is similar, if not greater than most light turbojet military trainers.
These performance aspects indicated that such an aircraft can be a plausible cross country sport aircraft which can cover a LOT of ground from one airport to another, in a short-duration flight. Depending on the specific flight profile, simulation proved that can cover more than 500 nautical miles.
VSKYLABS 'Test-Pilot': Rutan Model-158 Project for X-Plane 12:
The VSKYLABS Rutan Model-158 variant is an advanced flight simulation model of a high-performance turboprop aircraft, capable of flying approximately 1.5 flight hours up to ~30,000 feet while cruising and can cover more than 500 nautical miles in a single flight.
As with all VSKYLABS projects, actual and relevant real-life pilot-experience took a major part in the design, development and test flights process. In this specific project, several aspects of the aircraft had to be addressed or to be designed from scratch, to allow all required systems simulation and integrations.
The core of the project is a highly defined flight dynamics and PT-6A propulsion model which was built and refined to simulate the Model-158 variant in the most plausible and accurate way. In VSKYLABS perspective, this project reflects the basic concept of X-Plane flight simulator, where fictional aircraft concepts can be challenged and tested in an advanced flight simulation environment. Although it is a *fictional* variant of the Model-158, it is NOT a "science fiction" project. It is a highly defined concept demonstrator!
VSKYLABS ‘Test-Pilot’: Model-158 Project Highlights:
- VSKYLABS 'Test-Pilot' project.
- Highly defined flight dynamics model of the Model-158.
- Highly defined PT6 turboprop engine simulation (PT6A-28) including its associated peripheral systems.
- Built around the powerful, native X-Plane's Flight Model environment.
- Fully equipped aircraft with comprehensive systems simulation: Full PT6A-28 simulation, including auto-feathering and auto-ignition systems simulation. Electrical system. Lighting and warning systems. Comprehensive fuel system. Fire protection. Bleed air and pressurization systems. Pneumatic systems. Ice protection systems. Landing gears system. Flight controls. Oxygen system. Canopy system (seal and locking mechanism for pressurized cockpit).
- VR (Virtual Reality) Ready.
- Multi-Layer FMOD sound pack.
- 50-pages, comprehensive, illustrated Pilot Operations Manual, including checklists.
- Autoupdater based on the SkunkCrafts autoupdater (XP12 only) - all updates are being pushed smoothly without the need to re-download the entire base package (base package will be updated every once in a while to minimize the gap).
- Included Paint-Kit.
- Highly responsive VSKYLABS support forums.
More information and screenshots are available in the project page, at the VSKYLABS website: VSKYLABS Test-Pilot: Rutan Model-158 Project
Stay tuned for more exciting VSKYLABS development news!
VSKYLABS
