1. What is Pressure Altitude?

Definition: Pressure altitude is the altitude in the standard atmosphere where the pressure equals the measured station pressure.

Purpose: It's a critical parameter in aviation for aircraft performance calculations and flight level determination.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( P \) — Station pressure in hectopascals (hPa)
• 145442 — Constant representing the altitude where pressure would be 0 hPa
• 1013.25 — Standard sea level pressure in hPa
• 0.19026 — Exponent derived from atmospheric properties

Explanation: The formula calculates the altitude corresponding to the input pressure in the standard atmosphere.

3. Importance of Pressure Altitude

Details: Pressure altitude is used to determine aircraft performance characteristics like takeoff distance, climb rate, and true airspeed calculations.

4. Using the Calculator

Tips: Enter the station pressure in hPa (hectopascals). This is typically available from airport weather reports or altimeter settings.

5. Frequently Asked Questions (FAQ)

Q1: What's the difference between pressure altitude and density altitude?
A: Pressure altitude corrects for non-standard pressure, while density altitude also accounts for temperature variations affecting air density.

Q2: What is standard sea level pressure?
A: 1013.25 hPa (or 29.92 inches of mercury) is the internationally agreed standard atmospheric pressure at sea level.

Q3: When would pressure altitude equal true altitude?
A: Only when the actual atmospheric conditions exactly match the standard atmosphere (rare in practice).

Q4: How does pressure altitude affect aircraft performance?
A: Higher pressure altitudes mean lower air density, resulting in reduced engine power, lift, and propeller efficiency.

Q5: Can I use this for mountain flying?
A: Yes, but be aware that actual conditions may vary significantly from standard atmosphere, especially at high altitudes.