On the ground, if the altimeter is set to 29.92 inHg, the reading corresponds to

On the ground, if the altimeter is set to 29.92 inHg, the reading corresponds to

• A. Indicated altitude
• B. Density altitude
• C. Absolute altitude
• D. Pressure altitude

Answer: (D)

Setting the altimeter to the standard pressure of 29.92 inHg makes it read pressure altitude—the altitude in the standard atmosphere that corresponds to the current ambient pressure. On the ground, this reading shows how high you would be above the standard datum plane, not your true height above mean sea level or above the terrain. It isn’t density altitude, which factors in temperature and air density, nor indicated altitude which uses the local pressure setting to show height above sea level. It isn’t absolute altitude, which is height above the ground. So the ground reading with 29.92 inHg is pressure altitude.

Setting the altimeter to the standard pressure of 29.92 inHg makes it read pressure altitude—the altitude in the standard atmosphere that corresponds to the current ambient pressure. On the ground, this reading shows how high you would be above the standard datum plane, not your true height above mean sea level or above the terrain. It isn’t density altitude, which factors in temperature and air density, nor indicated altitude which uses the local pressure setting to show height above sea level. It isn’t absolute altitude, which is height above the ground. So the ground reading with 29.92 inHg is pressure altitude.