VSKYLABS Phoenix Air Phoenix LSA

The VSKYLABS Phoenix Air Phoenix Project

The VSKYLABS Phoenix Air Phoenix project for X-Plane flight simulator


The VSKYLABS Phoenix Air Phoenix Project

The development of the VSKYLABS Phoenix Air U-15 Project for X-Plane 11 was approved by Phoenix Air. Although acknowledged by Phoenix Air, it is an independent VSKYLABS project which is not affiliated with and/or endorsed by Phoenix Air.

Project Introduction:
The Phoenix Air Phoenix is my second, real-life LSA project for X-Plane flight simulator. Like in the VSKYLABS Aeropro EuroFOX project, this project's focus is about the virtual aircraft performance, simplicity and effectiveness of its design and engineering.

The project features the Phoenix U-15 aircraft, which is a kind of a 'hybrid' aircraft; powered aircraft by Rotax 912 ULS 100 hp engine, and at the same time, a high performance glider. I have plans to get further with this project and to develop the D-14 variant of the Phoenix, which is an electric powered, retractable landing gears motor glider.

The VSKYLABS Phoenix Air Phoenix project is under constant development. Package updates are to be expected. Update/upgrade plan is including (among other things): 3D modeling and aircraft performance refinements. The free updates are being pushed out automatically to all buyers.

Project's Update Log:

Project support:
You are invited to use the Phoenix LSA topic in the VSKYLABS Support Forums for feedback, questions, comments, bug reports etc.


Phoenix Air Phoenix background and history

The Phoenix Air Phoenix is a Czech low-wing, two-seat motor glider, designed and manufactured by Phoenix Air ( - developed by Martin Stepaneck) and provided as a complete ready-to-fly aircraft. The Phoenix was designed to comply with the Fédération Aéronautique Internationale microlight rules and US light-sport aircraft rules.

The aircraft is certified in the USA as an S-LSA Glider, and imported to the US by Phoenix Air USA (

The aircraft features a cantilever wing, a T-tail, a two-seats-in-side-by-side configuration, enclosed cockpit under a bubble canopy, fixed conventional landing gear and a 100 hp Rotax engine.

It is built from composites. Its 15 m span wing can be converted to 11 m by removing the wing tips and installing shorter ones for faster cruise speed when flown as a microlight aircraft. An electric powered version (D-14) is under development.

The Phoenix can be flown for hundreds or thousands of miles with either sets of wings. It is a super-versatile, state of the art light sport aircraft.

Useful External links and Documents:

Please refer the following documents (Pilot Operating Handbook) of the real Phoenix aircraft as the operation manual of the VSKYLABS Phoenix for use in X-Plane flight simulator, in terms of flying characteristics, handling, techniques etc...

Phoenix Air (main Czech website):

Phoenix Air USA:

Phoenix S-LSA U-15 Aircraft Operating Instructions:

AV WEB video overview of the Phoenix:

Light Sport and Ultralight Flyer look at the Phoenix:

Plane&Pilot - Phoenix Motorglider: Chase The Shouting Wind:

Nice video #1 (electric version):

Nice video #2 (towing):

Screenshots Gallery:

Video Gallery:

Operation supplement for X-Plane

Recommended Settings:

The VSKYLABS Phoenix Air Phoenix add-on is currently being tested and operated on a machine with these specifications:
  • CPU: Intel® Core™ i7-6700 CPU @ 3.40GHz × 8
  • Memory: 32 GB Memory
  • GPU: GeForce GTX 1070/PCIe/SSE2
  • X-Plane 11 (current version).
For balanced field of view, It is recommended to set the 'Lateral Field-of-View' to 85+ Degrees. This is done from X-Plane's rendering options windows in X-Plane.

Reference Screenshots:

Please use the following screenshots as a reference to the information that is described down this page. Please note that the model is constantly being updated and improved, so screenshot's details may vary a it can only get better than what you see ;)

Cockpit Panel - Various Switches and Handles:

The initial release version of the U-15 model, is equipped with a cockpit panel that is based on the 'Deluxe Standard Panel', as described in the Phoenix Air website (the following panel images are taken from the Phoenix Air USA website at: ).

Cockpit front panel - Various instruments in the front panel:

Notes (from left to right):
  • Master switch is the master power switch.
  • Starter Switch: To operate, point the mouse and click on the desire area ('OFF', 'L', 'R', 'BOTH', 'START'). 
  • Rescue system handle: Fires the Magnum Ballistic Parachute. To operate, "grab" the handle and pull it **ALL THE WAY** (you can push it back to reset the system).
  • Manual Feather handle:
    • It is a two-position handle. Click on the handle to toggle between 'Feathered' and 'Non-Feathered' positions.
    • In X-Plane, when switching the engine to 'OFF', the system auto-feathers the propeller. If you restart the engine, you have to set the handle **MANUALLY** to the 'Un-Feathered' position.
    • If you had started the engine and not moving upon throttle command...check this lever...your propeller is probably feathered ;) 
  • Cowl flap: Pull to close.
  • Parking Brake Handle - can be pulled gently for gradual braking, and locked in its aft position to serve as a parking brake.
  • Fuel Valve: To choose between 'L' , 'R', or 'OFF', just click on the selected side (left side is for 'L', right side is for 'R' and lower side is for 'OFF').
  • Variometer: Use the ON/OFF switch to operate, use the Volume knob to set the volume (for the Variometer as well as for the Stall warning system).

Cockpit lower panel - Various instruments in the front panel:

  • Spoiler control lever operations: 'Grab' the handle and set a desired position.
  • Flaps lever operations: 'Grab' the handle and set a desired position.
  • Trim lever:  'Grab' the handle and set a desired position.

Cockpit front panel - Avionics:

  • GPS: Click on the flat screen to get access to the GPS operation window.
  • Radios: Use the knobs to set frequencies and buttons to switch between the set and active.
  • Avionics Switches/Breakers: Point and click on the desire switch to toggle between 'ON' and 'OFF'.

Switching wingtips from 3D cockpit view:

The real-life Phoenix U-15 is coming with two sets of wingtips:
  • An extended wingtip that gives it a 15 meter wingspan (49 foot).
  • A short wingtip, that turns it into an 11 meter span (36 foot).
With the short tips on, it is more an airplane-like, a bit faster, more maneuverable, but it is still a glider (S-LSA certification wise).

In the VSKYLABS Phoenix U-15, switching between wingtip is very easy: simply click on the Airspeed Indicator (in 3D view mode) to toggle between short/extended wings. The flight dynamics model and the 3D model are biased so it turns practically into a 36 foot span aircraft in X-Plane (as seen in the screenshot below):

Flight Training Supplement:

The VSKYLABS Phoenix U-15 is utilizing X-Plane flight dynamics model to its maximum extent. The model is tuned to perform as close as possible to the real Phoenix. The tuning procedure is a sisyphic process and a major part of the development; the aircraft's virtual flight envelope is being explored and "opened" carefully, without compromising the performance of other flight regimes that are virtually accurate. Within the future updates, flight dynamics model refinements are to be expected.

Flying the VSKYLABS Phoenix U-15 in X-Plane should be performed as in the real aircraft. For your convenience, I've pasted down here some of the information and checklists that are available in the official Phoenix Air Manuals and from the U15 Phoenix S-LSA Glider Flight Training Supplement. Scroll down and get familiar with the aircraft's limitations, performance and flying procedures.

The information and checklists below are only to use with flight simulation software. It is not a replacement to any real aircraft checklists and documentations.

Aircraft Description:
The U15 Phoenix is intended for recreational, sport, cross-country and training. It is not approved for aerobatic operation.

The Phoenix is a single engine, carbon airplane with two side-by-side seats. The airplane is equipped with a fixed main wheel undercarriage with a steerable tail wheel. The fuselage is a carbon shell with carbon/kevlar seats integrated. Safety belts are attached to the seats and to a shelf intended for lightweight objects (headphones, maps, etc.).

The wing is a monospar construction with a sandwich skin composed of two layers of fiberglass with a foam core. Control surfaces are of the same construction.

The airplane is controlled by a dual push-pull control system, only the rudder drive is controlled by cable. The ailerons and elevator are controlled by the control stick located between the pilot's legs (co-pilot's). The rudder is controlled by the rudder pedals, flaps and spoilers are operated by control levers located between the pilots.

Operating weights and loading:
Minimum load solo ........................................ 144 lb
Maximum weight per seat ............................. 242 lb
Empty weight (standard).................................727 lb
Max. take-off weight ................................... 1,320 lb
Max. landing weight ................................... 1,320 lb
Max. baggage weight..................................... 110 lb

On-ground adjustable, 2 blade, composite propeller VARIA 1,6 is attached to the propeller flange with 6 bolts, and covered with a conic spinner.

Fuel and Fuel capacity:
Fuel specification:
Automotive Premium Unleaded per ASTM D 4814, minimum Octane 89 for Rotax 912 UL and minimum Octane 91 for Rotax 912 ULS.

Fuel capacity:
2 x wing fuel tank 13.2 gal each, 26.4 gal total.

Engine Manufacturer: Bombardier-Rotax GMBH
Engine Model: Rotax 912 ULS
Power Max. Take-off: 73.5 kW (100hp) at 5800rpm
Power Max. Continuous: 69 kW (95 hp) at 5500rpm
Cruising: 59 kW / 79 hp at 4800 rpm
Engine RPM Max. Take-off: 5800 rpm, max. 5 min.
Engine RPM Max. Continuous: 5500 rpm
Engine RPM Cruising: 4800 rpm
Engine RPM Idling: 1400 rpm
CHT Minimum: 60 C (140 F)
CHT Maximum: 150 °C (300 °F)
Oil temperature Minimum: 50 °C (120 °F)
Oil temperature Maximum: 130 °C (280 °F)
Oil Opt. operating: 90 °C – 110 °C (190-210 °F)
Oil p Normal: 2 – 5 bar (29 – 73 psi)
Oil p Maximum: 7 bar (102 psi) – for short time, After starting of a cold engine
Oil p Minimum: 0,8 bar (12 psi) – under 3.500 rpm
Fuel pressure Max: 0.40 bar (5.8 psi)
Fuel pressure Min:  0.15 bar (2.2 psi)

Operating Limitations:

Stalling speeds at maximum takeoff weight (Vs1 and Vs0 ):
Vs1 = 43kts
Vso = 38kts 

Flap extended speed range (Vs0 and Vfe):
Vfe = 80kts 

Maximum maneuvering speed (Va):
Va = 97 kts
Up to speed Va all control surfaces can be fully deflected

Never exceed speed (Vne):
Vne = 120 kts
From Va to Vne only 1/3 of the maximum deflection of control surfaces is allowed.
Crosswind and wind limitations for takeoff and landing:
Maximum demonstrated crosswind components for takeoff and landing is 23 kts. Cross wind takeoffs and landings demand a lot of training and skill, the higher the crosswind component, the greater your skill must be.

In gusty wind or wind speed more than 25 kts flight operations should be stopped.

Load factors:
From Vs0 up to Vne: +4 g / -2 g

Prohibited maneuvers:
The U15 Phoenix is not certified for aerobatics or spins.


Rate of climb: 
For Rotax 912ULS and VARIA 1.6 propeller the best rate-of-climb at MTOW is 1000 feet/min.

Climbing speeds: 
The best rate of climb speed is 58 kts CAS
The best angle of climb speed is 55kts CAS
Best gliding speed (minimum sink rate):

55 knots
Sink rate: ~180 feet/minute 
(Gliding ratio of ~1:30 - 1:32)

Maximum RPM - All information is for Rotax 912 ULS: 
Takeoff performance: 5800 rpm (max 5 minutes) 
Max. continuous performance 5500 rpm 
Maximum RPM (red line) 5800 rpm (max. 5 minutes) 
Idle RPM 1400 – 1800 rpm 
75% cruise RPM 5000 rpm

Time limit for the use of takeoff power: 
The limit for takeoff power if RPM is 5,800 rpm, and if all temperatures are in Engine Operating Manual limits is 5 minutes.

Fuel consumption and total usable fuel volume:
Fuel consumption at takeoff power 5.88 gal/h
Fuel consumption at cruising power 3.44 gal/h
Fuel consumption at 5,500 rpm 4.8 gal/h
Usable fuel volume 26 gallons

Flying the U15 Phoenix:
The Phoenix is an aerodynamically clean aircraft and a pilot being transitioned to the Phoenix needs to be trained to manage his airspeed carefully. The rapid acceleration to takeoff and angle of climb is different from conventional aircraft. Landing the Phoenix requires controlling and reducing airspeed in the pattern and final approach to landing. After practice the Phoenix can be landed in very short airfields safely.

Normal Procedures:
  • Checklist before engine start:
    • Complete pre-flight checklist
    • Remove emergency parachute system lock
    • Elevator trim in middle position
    • Flaps set to 0°
    • Altimeter set
    • Check the wind direction.
    • Canopy lock secured
    • Radio and all electric equipment switched off before engine start
    • Clear the area around the airplane of persons and obstacles – especially around the propeller!
  • Engine Start:
    • Fuel valve open
    • Choke (if engine is cold) on
    • Throttle control position idle
    • All electric equipment off
    • Parking brake on
    • Ignition on both circuits
    • Verify prop unfeathered
    • Ignition key turn to start position
    • Crank the engine for maximum 10 seconds.
    • Allow the starter to cool for two minutes if the engine does not start.
    • As soon as the engine starts, set the throttle level in such a way that the engine runs smoothly at minimum RPM
    • Check the oil pressure immediately
    • Close the choke
    • Run the engine until warm at a middle RPM
    • Switch on all additional instruments
    • If the airplane rolls and cannot be stopped with the brakes, stop the engine immediately!
    • The tail wheel is directly linked to the rudder pedals for taxiing, takeoff and all maneuvers on the ground.
  • Before take-off (CCCCIGAAR – Lights, Camera, Action):
    • Controls -check for free movement
    • Canopy -closed and locked
    • Choke -off
    • Cowl flap -open
    • Instruments -set and in the green
    • Gas -fuel valve on left tank
    • Attitude -trim set for take-off
    • Airbrakes -closed and locked
    • Run-up -3000rpm - check magnetos (in the starting switch).
    • Lights -strobe/nav lights on
    • Camera -transponder on alt
    • Action -fuel pump on
  • Takeoff:
    • If the RWY and approach to the RWY are clear, roll out to the takeoff position
    • Confirm plane is centered on runway
    • Controls are in proper position for takeoff
    • Smoothly apply throttle to fully open (forward)
    • If it is possible takeoff directly into the wind (wind limitations - see AOI)
    • Keep the stick position 2 inches forward of full aft
    • After takeoff lower the nose slowly and as airspeed reaches 60 kts climb to a minimum height of 300 ft. Do not start turn until minimum altitude 300 ft!
    • Slightly reduce the throttle to 5000 rpm.
    • Turn electric fuel pump off when return to runway is possible
  • Climb:
    • Keep the climb speed at 60 kts.
  • Basic limitations:
    • Phoenix is not certified for aerobatics
    • Fights are only to be made under VFR conditions
    • No night flights permitted without navigation and strobe lights
    • Steep turns beyond 60° should not be performed
  • Cruising flight:
    • During cruising flight RPM of 4000 - 5000 rpm should be used.
    • The maximum permissible speed of 119 kts should not be exceeded.
    • For normal cruising flight bring the airplane to the desired cruising speed in level flight by observing VSI and altimeter.
    • Adjust throttle and trim to hold altitude.
    • During flight monitor fuel indicators.
  • Banked turn:
    • Each of turn should be made with the coordinated use of the ailerons and rudder
    • Steep turns exceeding 60°are not recommended.
    • Banked turns with more than 30° should not be carried out less than 50 kts.
  • In-flight engine off:
    • Speed 60 kts
    • Avionics off
    • Ignition key to off position – prop feathers
    • Master switch off, or avionics on as desired
    • Run engine every hour for battery charging or monitor battery voltage
  • In-flight engine start:
    • Altitude above 1500’AGL if away from an airport
    • Speed 60 kts
    • Avionics off
    • Choke off
    • Throttle at idle
    • Master switch on
    • Fuel pump on
    • Ignition key on both circuits, verify prop unfeathered
    • Ignition key to start
    • If engine does not start within 4 seconds, use ½ choke to start Check oil pressure
    • Choke off
    • Fuel pump off
    • RPM below 2500 rpm until oil temp is 122°F (50°C) but use full power if necessary
  • Stalls:
    • Phoenix is very resistant to stalling. If you feel the tendency to roll, you can easily react with rudder.
    • If you are close to the ground keep the speed at least 60 kts.
    • If you enter a spin use opposite rudder input, keep the ailerons centered and gently level the plane with the elevator.
  • Landing:
    • Land always into the wind, or the runway with least crosswind if possible.
    • The final approach to landing is to be carried out in level altitude.
    • Engine power: about idle – 20% (slightly above idle)
    • Approach speed: about 55 kts
    • Flaps at 0° or +10°
    • At the distance of 3 ft above the ground use elevator and land airplane gently. It is recommended to touch the ground with full airbrakes.
    • Flights over obstacles during approach to landing should be avoided
  • Engine stop:
    • Under normal conditions, the engine is cooled during approach and rollout, therefore it can be stopped by turning the ignition switch off (both magnetos)
    • The radio, transponder and all optional electric equipment should be switched off BEFORE engine is stopped.

This page is still ** UNDER CONSTRUCTION **
Standby for more...soon!

Stay Tuned :)