The Airfield: Structure, Traffic Rules and Procedures

2. Airport Procedures

2.8. Standard Landing from a 3° Glidepath

A little basic knowledge of the landing approach is necessary for you to complete a successful landing. Many airplanes are designed to approach the airport on a glidepath of 3°. Approximately 320 feet per nautical mile. So, it is possible to calculate which height you should have at which point on this 3° glide path. It is therefore possible to fly into the 3° glide path at any range at the approximately suitable altitude. During landing exercises you will quickly notice that there is a clear difference between how far you are from the airfield and how high you are. Therefore it is necessary to define a standard case. This is the 3° glidepath. That is why it is the first step for every landing to fly the aircraft as close as possible to this optimal case.

Glidepath

The correct glide path for landing is 3°. If it is less than 3° there is a possibility that we will land before the threshold. If the glide angle is too steep our sink rate will be too high and we could damage the landing gear because we put the aircraft down too hard.

glide path, picture of Eagle, common free

Inclination angle

The Angle of Attack (AOA) is the angle between the flight direction and the longitudinal axis of the aircraft. This angle should be between 7.4° and 8.8° during landing. The angle of attack is directly related to the airspeed.

AOA, Image of Eagle, Common Free


Airspeed

The airspeed must be selected so that the appropriate angle of attack is achieved. In addition, the speed depends on the weight of the aircraft. Basically the following statements can be made.

Greater weight = Higher landing speed
Lower airspeed = Higher angle of attack.

Example: For missions from the F/A-18C basic course you should calculate with approx. 140 knots.

Precision Approach Path Indicator (PAPI)

Many airports have 4 signal lights (PAPIs) next to the runway touch down point which display your glide path. Each light has a white segment and a red segment. Each is anglesd slightly differently so that they display as follows.

2x white and 2x red would be a correct glide path. As you can see in the following picture. If all are red you are too low and if all are white you are too high.

Easy to remember is:

  • ALL ARE WHITE - "Check your height" = too high
  • RED AND WHITE - "You are right" = correct height
  • ALL ARE RED - "You are dead" = too low



Glide path, image of Eagle, Common Free