Key Vocabulary

• Composite Materials: Materials made from two or more constituent materials with significantly different physical or chemical properties, such as glass, carbon, Kevlar, foam, and fabric, used in aircraft construction for strength and lightness.
• Electro-mechanical Elevator Trim: A system using electric motors and mechanical components to adjust the elevator trim, allowing the pilot to reduce control forces.
• Flaperons: Control surfaces that combine the functions of flaps and ailerons on the trailing edges of aircraft wings.
• Horizontal Opposed Engine: An engine design where cylinders are arranged horizontally opposite each other, commonly used in light aircraft for smoothness and balance.
• MTOW (Maximum Take-Off Weight): The maximum weight at which the aircraft is permitted to take off, here 472.5 kg.
• MLW (Maximum Landing Weight): The maximum permissible weight for landing, equal here to MTOW.
• Parachute Rescue System (GRS): A rocket-deployed emergency parachute designed to safely lower the entire aircraft to the ground.
• Rotax 912 A Engine: A four-cylinder, four-stroke, horizontally opposed, 80 HP aircraft engine with dual electronic ignition.
• T-tail: Aircraft tail configuration where the horizontal stabilizer is mounted at the top of the vertical stabilizer forming a 'T' shape.
• Tricycle Undercarriage: Landing gear consisting of three wheels – two main wheels and a steerable nose wheel.

Key Concepts

Aircraft Design and Structure

• The Virus SW-80 is a two-seat, high-wing microlite aircraft primarily constructed with composite materials that ensure strength and lightweight.
• Features a fixed tricycle undercarriage with hydraulic disc brakes on main wheels and steerable nosewheel controlled via rudder pedals.
• Cockpit safety includes anti-UV shatter-resistant windows, 'H' type three-point harnesses, and ventilation systems including cabin heating and demisting via engine heat.

Flight Controls

• Control surfaces include flaperons (combining aileron and flap functions), elevators, and rudder.
• Control sticks laterally operate flaperons; a flap lever offers three positions (0°, 15°, 25°).
• Elevator trim is electro-mechanical, controlled by cockpit switches.
• Rudder connected by cables to pedals with nose wheel steering via the same pedals.

Engine and Propulsion

• Powered by an 80 HP Rotax 912 A four-cylinder, four-stroke, twin-carbureted, horizontally opposed engine.
• Cooling system utilizes liquid-cooled cylinder heads, ram air-cooled cylinders, and oil cooling.
• Features dry sump lubrication, electric starter, and an integrated 12V, 250W alternator.
• Fixed-pitch, two-blade propeller with a reduction gearbox (ratio 1:2.27) and mechanical shock absorber.

Fuel and Electrical Systems

• Fuel stored in vented fuselage tank with filters, mechanical fuel pump, and optional electric pump.
• Electric system includes a lithium iron phosphate battery with Battery Management System; powers lighting, communications (Garmin GPS), fuel pump, starter, avionics.

Parachute Rescue System

• Rocket-deployed parachute located behind right seat in baggage compartment.
• Activated manually via an overhead pull handle, deploying full canopy in ~3.2 sec.

Operational Limitations and Flight Performance

• Maneuvers like stalls and lazy eights have minimum altitude requirements; spins prohibited below 2500 ft AGL.
• Day VFR operation only; prohibitions on flying in heavy rain, icing, thunderstorms, IMC/IFR, and ambient temperatures above 55°C.
• Tailwind effects on takeoff and landing distances significantly increase required runway lengths.
• Soft grass runways increase takeoff distance by 20%.

Aircraft Specifications and Flight Parameters

• Wing span: 10.5 m; Length: 6.5 m; Height: 2.05 m.
• MTOW and MLW: 472.5 kg; Useful load: 197.5 kg; Baggage limit: 20 kg.
• Maximum RPM (5 min max): 5800 rpm.
• Takeoff distances at MTOW: 140 m ground roll, 225 m over 50 ft obstacle.
• Best climb speed: 76 knots; climb rate: 1220 ft/min.
• Stall speeds: Vs = 43 knots (clean), Vso = 35 knots (flaps 25°).
• Normal operating speed (VNO): up to 108 knots.
• Maximum maneuvering speed (VA): 86 knots.
• Airspeed indicator bands: White (35–70 kts, flaps range), Green (43–108 kts normal range), Yellow (108–135 kts caution), Red line at 135 kts (VNE).

Important Data and Formulas

• Propeller Diameter: 1650 mm (1.65 meters).
• Reduction Gearbox Ratio: $1 : 2.27$ (engine speed : propeller speed).
• MTOW = MLW: 472.5 kg.
• Useful Load: 197.5 kg.
• Takeoff ground roll distance (no obstacle): 140 m at MTOW.
• Takeoff distance over 50 ft (15 m) obstacle: 225 m at MTOW.
• Best climb speed ($V_{climb}$): 76 knots.
• Best climb rate ($R_{climb}$): 1220 ft/min = 6.1 m/s.
• Stall speeds:
  • $V_s$ (clean) = 43 knots.
  • $V_{so}$ (flaps landing) = 35 knots.
• Airspeed Indicator Bands:
  • White Band: 35–70 knots (flaps operating range).
  • Green Band: 43–108 knots (normal operating range).
  • Yellow Band: 108–135 knots (caution range).
  • Red Line (VNE): 135 knots.
• Maximum RPM Range:
  • Max limited RPM: 5800 rpm for 5 minutes.

Additional Critical Aspects

Principles and Safety Systems

• The aircraft incorporates a dual electronic ignition system (breakerless capacitor discharge) for enhanced engine reliability.
• The mechanical overload clutch in the propeller gearbox helps protect the engine from shock loads.
• The parachute rescue system adheres to rapid deployment principles (~3.2 seconds to full canopy inflation), offering a last-resort safety measure for the entire aircraft.

Operating Procedures and Limitations

• Specific altitude floor requirements for maneuvers ensure safety margins: Stalls above 1500 ft AGL, spins above 2500 ft AGL.
• Operational restrictions emphasize the aircraft’s use under VFR Day only, highlighting its microlight category and design limitations.
• Environmental limitations include no operation in icing conditions, thunderstorms, heavy rains, and high ambient temperatures over 55° C.

Methodologies for Control and Adjustment

• Flight controls are designed for dual pilot operation with mirrored sticks and pedals.
• Flaperon design replaces traditional flaps and ailerons with a single articulated surface, allowing simplified control linkage.
• Ergonomic adjustments include seat cushion removability and adjustable rudder pedals for individual pilot fit.

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Summary

This set outlines the Virus SW-80, a composite microlight aircraft notable for its advanced materials, efficient Rotax engine, and balanced control surfaces including flaperons. Its fixed tricycle undercarriage and robust safety features such as the parachute rescue system reflect design emphasis on safety and reliability for light sport flying under VFR conditions. Performance specifications and critical operational limits provide the framework for safe and effective aircraft operation.