Refer to figure.
First we will determine the time to reach cruise altitude (10 500 ft) and the time to reach the departure airfield altitude (2000 ft), then we will subtract them to obtain the climb time.
Step 1: Determine the time to reach cruise altitude
We need pressure altitude and Outside Air Temperature (OAT) to calculate the time. Then we can follow these steps.
The steps are marked in red.

1. Since the OAT is standard (ISA), start at the point where the 10 500 ft (midway between 10 000 ft and 11 000 ft) pressure altitude line intercepts the “STD TEMP” line.
2. From that point, move horizontally to the right until you intercept the “TIME - MIN” line.
3. Then move vertically downward to read a time of 23 min.

Step 2: Determine the time to reach departure airfield altitude
We need pressure altitude and Outside Air Temperature (OAT) to calculate the time. Then we can follow these steps.
The steps are marked in cyan.

1. Enter the graph from bottom left at OAT +20°C.
2. Move vertically up to the pressure altitude of 2000 ft.
3. From that point, move horizontally right until you intersect the “TIME - MIN” line.
4. Then move vertically downward to read a time of 3 min.

Step 3: Calculate the time taken for climb
We can calculate the time taken for climb by subtracting the time to reach the departure airfield altitude from the time to reach the cruise altitude.

• Time taken (min) = Time to reach cruise (10 500 ft) - Time to reach departure airfield (2000 ft)
• Time taken = 23 min - 3 min
• Time taken = 20 min