AVIATION & AERONAUTIC CALCULATOR
Decision Height To Dh
A precise tool.
What is the Decision Height To Dh & How does it work?
Decision Height (DH) is the height above ground level at which a pilot must be able to see and identify visual references in order to continue the approach and land safely.
Descent Altitude (DA), also known as Decision Altitude, is similar to DH but is referenced to mean sea level instead of ground level. The conversion between DA and DH depends on the airport’s elevation above sea level.
DH = DA – text{Airport Elevation}
DA = Descent Altitude in feet
Airport Elevation = Elevation of the airport above sea level in feet
Airport Elevation = Elevation of the airport above sea level in feet
Parameters
Result
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Frequently Asked Questions
What is the difference between Decision Height and Descent Altitude?
Decision Height (DH) is the height above ground level at which a pilot must see visual references to continue landing. Descent Altitude (DA), or Decision Altitude, is referenced to mean sea level.
How do I calculate Decision Height if I know the Descent Altitude and Airport Elevation?
Subtract the Airport Elevation from the Descent Altitude to get the Decision Height. DH = DA – Airport Elevation.
Can you explain why Decision Height is important in aviation?
Decision Height is crucial because it ensures pilots have enough time and visual references to safely land an aircraft, preventing potential accidents due to poor visibility or unexpected obstacles.
What happens if a pilot reaches the Decision Height without visual references?
If a pilot cannot see required visual references at Decision Height, they must execute a go-around procedure and abandon the landing attempt.
How does airport elevation affect the calculation of Decision Height?
Higher airport elevations result in higher Decision Heights because pilots need more time to identify visual references as they approach from greater altitudes.
Is there a standard unit for measuring Descent Altitude and Airport Elevation?
Yes, both Descent Altitude and Airport Elevation are typically measured in feet.
Can this calculator be used for international airports?
Yes, the calculator can be used for international airports as long as you input the correct Descent Altitude and Airport Elevation in feet.
Results are for informational purposes only and do not constitute professional advice.