Which altitude type is indicated when the altimeter is adjusted to 29.92 inHg and read off the instrument?

Which altitude type is indicated when the altimeter is adjusted to 29.92 inHg and read off the instrument?

• A. Pressure Altitude
• B. True Altitude
• C. Density Altitude
• D. Absolute Altitude

Answer: (A)

Setting the altimeter to 29.92 inHg shows pressure altitude. This is the height above the standard datum plane in the international standard atmosphere, where the pressure equals 29.92 inHg. Using this standard setting removes local pressure and temperature variations, giving a consistent reference for flight levels and separation. True altitude would require the local QNH (actual sea-level pressure) to reflect height above mean sea level, which the 29.92 setting does not provide. Density altitude combines pressure altitude with nonstandard temperature to reflect air density, not what the instrument directly indicates with the standard setting. Absolute altitude is simply height above the ground, which also isn’t what the instrument shows under a standard pressure setting. Therefore, the reading with 29.92 inHg is pressure altitude.

Setting the altimeter to 29.92 inHg shows pressure altitude. This is the height above the standard datum plane in the international standard atmosphere, where the pressure equals 29.92 inHg. Using this standard setting removes local pressure and temperature variations, giving a consistent reference for flight levels and separation.

True altitude would require the local QNH (actual sea-level pressure) to reflect height above mean sea level, which the 29.92 setting does not provide. Density altitude combines pressure altitude with nonstandard temperature to reflect air density, not what the instrument directly indicates with the standard setting. Absolute altitude is simply height above the ground, which also isn’t what the instrument shows under a standard pressure setting. Therefore, the reading with 29.92 inHg is pressure altitude.