1. What is Pressure Altitude in Aviation?

Definition: Pressure altitude is the altitude in the standard atmosphere where the pressure equals the current atmospheric pressure.

Purpose: It's crucial for aircraft performance calculations, density altitude determination, and flight planning.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• Pressure Altitude — Calculated pressure altitude (feet)
• Altitude — Current indicated altitude (feet)
• Kollsman Setting — Current altimeter setting (inches of mercury)

Explanation: The formula adjusts your current altitude based on how much the current pressure differs from standard pressure (29.92 inHg).

3. Importance of Pressure Altitude

Details: Pressure altitude is used to determine aircraft performance, calculate density altitude, and ensure proper separation between aircraft.

4. Using the Calculator

Tips: Enter your current altitude in feet and the current altimeter setting (Kollsman setting) in inches of mercury. The standard pressure is 29.92 inHg.

5. Frequently Asked Questions (FAQ)

Q1: Why is 29.92 used in the formula?
A: 29.92 inches of mercury is the standard pressure at sea level in the International Standard Atmosphere (ISA).

Q2: When would pressure altitude equal indicated altitude?
A: When the altimeter setting is exactly 29.92 inHg, pressure altitude equals indicated altitude.

Q3: How does pressure altitude affect aircraft performance?
A: Higher pressure altitudes mean reduced aircraft performance - longer takeoff rolls, reduced climb rates, and higher true airspeeds.

Q4: What's the relationship between pressure altitude and density altitude?
A: Density altitude is pressure altitude corrected for non-standard temperature, which further affects aircraft performance.

Q5: Why do pilots need to calculate pressure altitude?
A: For flight planning, performance calculations, and to ensure proper terrain clearance when flying in areas with non-standard pressure.