What is a Flight Simulator?
Flight Trainer circa 1915
Early Link Trainer
Redifon Comet 4B on Motion
Redifon DC-10 Simulator Cutaway
RAF Jaguar flight simulator
CAE A380 Simulator
CAE A380 Simulator
AMME Variable Stability Flight Simulator
A flight simulator is any system that attempts to reproduce the experience of flying as realistically and accurately as possible. Flight simulation is necessary because unlike many other vehicles aircraft are complex systems that are extremely hazardous to fly without the proper training. Moreover, every different type of aircraft is a unique system that can exhibit extremely different flight stability characteristics. Due to this diversity in aircraft stability characteristics, pilots are required to be specifically rated for various aircraft types, to ensure that they are adequately proficient in the handling of the aircraft in different meteorological conditions.
Since the early days of aircraft development flight simulation has been used to train pilots and crew. This process allows the pilot to be familiarized with the aircraft and its behaviour in flight with no risk to the instructor or their own lives. Moreover, it saves on the expense of training pilots in real aircraft that have limited air lifetimes and require fuel and maintenance.
CAE Airbus A380 Simulator
An video example of a commercial Airbus A380 Simulator is given below. This simulator, constructed by CAE is specific to the A380 and is used by airlines such as Qantas to train pilots without the expense of real flying. A pilot can therefore be evaluated as competent to fly the real A380 without actually having been in the aircraft.
Rapid Prototyping - Engineering Simulators
As modern computing power has grown different applications of flight simulation have emerged. The simulation systems in the modern era are becoming so accurate that they can actually be used to design the aircraft. This process is known as rapid prototyping and is an iterative process of design and computer aided simulation. It applies to all fields of engineering, developing almost any system.
Aerospace rapid prototyping simulators are known as engineering flight simulators. They allow engineers developing an aircraft system to refine their design in the software environment, prior to committing to producing the real life system prototype. Moreover, engineering flight simulators also present an opportunity to develop flight software within a virtual environment, prior to implementing the software in the on -board computer systems of an aircraft.
Flight simulation systems vary greatly in complexity. A simple video game is an attempt at replicating the feeling of flying. We can then add more complexity by more accurately simulating the aircraft flight mechanics and flight environment. Such simulators include Microsoft Flight Simulator, X-Plane, Flight Gear, Aerowinx Precision Simulator and there are many others. All of these PC based simulators have different levels of realism and focus on different areas of the simulation. However, they all lack the very important element of motion.
Simulators capable of motion are generally professionally manufactured simulators, built for specific pilot or crew training exercises. These simulators are extremely expensive and built to a very high level of accuracy and realism. Pilots are relying on the accuracy of these simulations to learn how to fly an aircraft. Motion capable simulators can be either, three degrees of freedom (3DOF) or six degrees of freedom (6DOF). The AMME Variable Stability Flight Simulator produces 3DOF motion and is an acceleration based motion platform.
Pilots experience the motion of simulators through the use of vestibular reflexes, which are used by the body to maintain postural stability. Accessing these reflexes is critical to providing the body with the feeling of synchronised motion. There are three classes of sensory input that affect the vestibular reflexes:
- Vestibular System
- Visual Inputs
The proprioceptors are used by your body to provide an understanding of where the body is located in space, according to external forces that act on the body. They are located in the body's muscles, tendons, joints and the inner ear and send signals to the brain regarding the body's position.
The Vestibular System provides the body with a balancing and equilibrium system. It is contained within the inner ear and includes the vestibular organs, ocular system and muscular system. It consists of three semicircular canals, each arranged at right angles to one another to allow the detecting of movement in three planes: longitudinally, laterally and vertically.
The human eye provides the most important source of information in the simulation of motion. The visual images from the eye provide inputs to your brain that are interpreted to determine the aircrafts position, velocity and attitude in three dimensional space. Consequently the direct synchronisation of the visual inputs with the movement of the simulator is extremely important. If the visual system does not react with the motion system in real time, then motion sickness can occur and the simulation experience does not feel real and is not accurate. Often, after flight tests, simulation timing would be slowed or sped up to match that experienced by test pilots.