Aircraft flight mechanics

The flight mechanics is one of the engineering sciences and describes the behavior of bodies that move in the atmosphere by means of aerodynamics, aircraft. In contrast to the aerodynamics of flight mechanics does not describe the physical processes at individual aircraft components, but the behavior of the overall system of the aircraft. The basic task of the flight mechanics is to calculate position, attitude and airspeed of a missile at any time. This is done with the aid of motion equations ( equations of motion ) consisting of a system of coupled differential equations. The aircraft is usually treated as a rigid body.

Study

Flight mechanics is a part of engineering curricula Air and Space and Aeronautical Engineering.

Basics

The theoretical basis for the flight mechanics form the mathematics, physics and aerodynamics. The flight mechanics uses this to describe what flight characteristics owns an airplane and which flight services can provide it.

Important factors are the lift force generated by the wings and the aerodynamic drag of the aircraft, the weight force acting in the center of gravity, the thrust generated by the engines, and the control forces generated at the control surfaces and caused by the respective forces torques. In addition to the forces mentioned above, the inertia of the aircraft or its components plays a role.

Since the equations to be solved are very complex systems in general, one is this reliant on powerful computers for the numerical solution. Estimating individual characteristics of an aircraft, it is common practice to simplify the equations and thus to solve sub-problems. Usual, for example, a distribution of the motion of the aircraft in the pure longitudinal movement, at which the airplane only about the transverse axis rotates (definition of the transverse axis ) and the lateral movement takes place around the longitudinal axis at a rotation and yaw.

In addition, a distinction is made between non-stationary and stationary processes. In non-stationary processes is primarily concerned with the immediate response of the aircraft to control inputs or external disturbances (eg wind gusts). As a steady flight condition is referred to a condition that arises when all the forces over a longer period remain constant. A simple example for a steady flight condition is the unaccelerated horizontal straight flight at which the aircraft is traveling at a constant speed and altitude in one direction. But even a straight flight with a constant radius and bank angle may be a stationary flight condition. Such steady flight conditions arise in reality often only after long settling -in. The aircraft shuttling between various flight conditions until it finally remains in steady flight condition. Based on the calculation of such processes statements about the static stability of the aircraft can be made.

The steady flight conditions essentially determine the flight characteristics of the aircraft. These are the possibilities of the airplane, with respect to the maximum and minimum speed, maximum altitude, takeoff and landing distance, maximum take-off mass and others. Aspects of flight performance are presented in envelopes. The picture shows an example of such an envelope. Entered the limits within which an aircraft can move.

Subregions

The flight mechanics provides the basis for a variety of sub-areas in the field of aerospace:

Flight Performance: Typical questions here are, for example, minimum speeds, range, maximum endurance, boost income, acceleration, take-off and landing distance, etc.

Flight Guidance: A distinction is made between flight guidance by a human and automatic flight control. Under automatic flight control refers to the autopilot, but also designed to increase the stability and fly- by-wire systems.

Flight Simulation: In flight simulation, the equations of motion are used to simulate aircraft movements, often even before the associated aircraft was built. So can be based on the flight dynamics calculations, evaluate the flight characteristics of a structure in advance.

• Engineering