Question

When Does the Altimeter Get Set to Standard Pressure?

a) Only during instrument approaches
b) At the beginning of each flight
c) When crossing a transition altitude
d) When descending below 10,000 feet

Answer 1

The altimeter is set to standard pressure when an aircraft climbs through the transition altitude, which varies by region but is critical for maintaining a uniform reference for vertical separation in upper airspace.

Step-by-step explanation:

The altimeter is an instrument used in an aircraft to measure the altitude above a predefined reference level, often sea level. Pilots set the altimeter to standard pressure at a specific point during a flight. This point is known as the transition altitude.

Pilots set the altimeter to a standard pressure setting, typically 29.92 inches of mercury (Hg) or 1013.25 hectopascals (hPa), when climbing through the transition altitude. The transition altitude varies by country and region but generally lies between 18,000 feet in the United States and a few thousand feet in Europe. The standard setting helps ensure that all aircraft in the upper airspace are referencing the same pressure setting on their altimeters, which contributes to vertical separation and collision avoidance.

The transition altitude is not to be confused with the transition level, which is used when descending. To answer the student's question, the altimeter is set to standard pressure when crossing the transition altitude during the climb.