Gross Flight Path Gradient is the average performance expected from the aged fleets of the a/c.
Net Take off Flight Path performance is calculated by deducting 0.8 % from the Gross Take off Flight Path Gradient for Take off and Landing calculations.
The Net Take off Flight Path should give an obstacle clearance by at least 35 feet from the surrounding structures in the aerodrome vicinity.
For En route Flight Path calculations the Net Flight Path Gradient is calculated by deducting 1.1 % from the Gross Flight Path Gradient, considering critical engine failed and the other at Maximum Continuous Thrust.
Runway slopes are considered only when above or below -0.2°
Approach Climb – A/c in approach configuration with a failed engine and max continuous power on live engine, with approach flaps and landing gear retracted, speed not less than 1.5 VSO (Landing Configuration). The a/c should be able to maintain a minimum Climb Gradient of 2.1%.
Landing climb – A/c in landing configuration, with landing flaps and landing gear extended, both eng operating normal and on Take off thrust, speed not less than 1.3 VSO (Landing configuration).
The a/c should be able to maintain a minimum Climb Gradient of 3.2%.
TAKE OFF DISTANCE – is the distance from the starting point to the screen height
(A/c reaches 35 feet at the end of Runway or Clearway).
TAKE OFF FLIGHT PATH – is the distance a/c travels from Screen height to a point a/c climbs to 1500 feet.
TAKE OFF PATH – is the distance from the starting point to the point a/c climbs to a height of 1500 feet.
En route Segment – is the flight path of the a/c from 1500 feet height above the departure airfield to the 1500 feet height above the destination airfield.
The whole segment is considered at critical engine failed and other at Maximum Continuous Thrust.