METEOROLOGY – ATMOPHERIC PREURE & ALTIMETRY CALCULATOR
Qnh Qfe Qff
A precise tool.
What is the Qnh Qfe Qff & How does it work?
Atmospheric pressure is a force per unit area exerted by the weight of air in the atmosphere. It varies with altitude, temperature, and humidity.
QNH (Quelle Niveau de l’Homme) is the atmospheric pressure adjusted to sea level. QFE (Quelle Fixe de l’Élevation) is the atmospheric pressure at an airport’s elevation. QFF (Quelle Fixe de la Flotte) is the atmospheric pressure adjusted to a standard reference height.
P_{text{QNH}} = P_{text{local}} + h cdot left(1 – frac{T}{T_0}right)^{5.26}
PQNH = QNH pressure, Plocal = local pressure, h = height above sea level, T = temperature at local altitude, T0 = standard temperature at sea level
Parameters
Result
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Frequently Asked Questions
What is QNH in aviation?
QNH is the atmospheric pressure adjusted to sea level, used to set altimeters for safe flight.
How do I calculate QFE from local pressure?
QFE is calculated by subtracting the height of the airport above sea level from the QNH value.
What does QFF stand for in aviation?
QFF stands for Quelle Fixe de la Flotte, which is atmospheric pressure adjusted to a standard reference height.
How do I convert QNH to QFE?
To convert QNH to QFE, subtract the airport’s elevation above sea level from the QNH value.
What is the formula for calculating QNH?
The formula for QNH is P_QNH = P_local + h * (1 – T/T_0)^5.26PQN, where P_local is local pressure, h is height, T is temperature, and T_0 is standard temperature.
Why is it important to know QFF in aviation?
QFF helps pilots compare pressures at different airports by adjusting them to a common reference height.
How does temperature affect the calculation of atmospheric pressure?
Temperature affects the calculation as it influences the density of air, which in turn impacts the pressure readings.
Results are for informational purposes only and do not constitute professional advice.