Approach Gradient

The approach gradient refers to the rate of ascent or descent that an aircraft must maintain while approaching or departing from an airport. It is typically expressed in terms of vertical distance traveled per horizontal distance covered.

Importance of Approach Gradient

The approach gradient is crucial for ensuring the safety and efficiency of aircraft operations near airports. It determines the aircraft’s performance capabilities, the required runway length, and the obstacle clearance criteria for a specific approach or departure procedure.

Calculation of Approach Gradient

The approach gradient is calculated using the ground and airspeed of the aircraft, as well as the rate of climb or descent required. It takes into consideration factors such as wind, temperature, altitude, and aircraft weight to determine the maximum allowable gradient for a given situation.

Types of Approach Gradient

There are two main types of approach gradients: obstacle clearance gradient and departure climb gradient.

1. Obstacle Clearance Gradient

The obstacle clearance gradient is the minimum gradient that an aircraft must maintain during the initial climb after takeoff or the final descent before landing to ensure clearance over any nearby obstacles, such as buildings, mountains, or trees.

2. Departure Climb Gradient

The departure climb gradient refers to the minimum gradient required for an aircraft to safely climb after takeoff and clear any obstacles or terrain within a specified distance from the end of the runway.

Regulatory Standards

Aviation authorities, such as the Federal Aviation Administration (FAA) in the United States, provide specific standards and guidelines for approach gradients based on the type of aircraft, runway characteristics, and other operational factors. These standards aim to maintain safety and ensure that aircraft can safely navigate the surrounding airspace.