Descent (aeronautics)

The descent is a maneuver of an aircraft to reduce the flying height (eg when landing ).

The rate of descent, which is the vertical speed in descent is given in feet per minute ( fpm) or in m / s and measured by the variometer.

Formulas

Landing approach

Rules of thumb for calculating the height or the distance for a standard 3 ° Sinkflugpfad (E = 1:19 ) for the landing:

• Altitude ( in feet ) = Distance ( NM) * 1000 /3 ( 1 ft = 30.48 cm; 1 NM = 1852 m)
• Distance ( NM ) = altitude ( in feet ) * 3/1000

Rate of descent

The settling velocity of non-powered aircraft calculated by the following formula:

= Vertical velocity in m / s   = Aircraft mass in kg   = Drag coefficient of the aircraft   = Acceleration in m/s2 (~ 9.8 )   = Air density in kg/m3   = Lift coefficient for minimum sink   = Wing area in m2

Special forms of descent

A special case of descent is the swoop of combat aircraft, wherein the aircraft is controlled steeply downward.

For a few seconds and the parabolic flight is a steep descent.

With balloons, parachutes and the like do not talk of descent, but simply of " sinking".

The so-called emergency descent (german emergency descent ) is a special form of the descent. It is performed after loss of pressure in the cabin or for the purpose of evading a collision course with eg. The rate of descent of a 747-400 is 2000 ft / min without and at 3000 ft / min Speed ​​Brakes. In the event of a pressure loss, however, has to be decreased considerably faster.