Refer to figure.
1. Since the OAT is +26°C at Sea Level, it means that the atmosphere is 11°C hotter than ISA.

2. ISA temperature at 6000 ft is: +15°C - 2°C x 6000 ft / 1000 = +3°C.

3. With an atmoshpere hotter by 11°C, the OAT at 6000 ft will be: +3°C + 11°C = +14°C.

To determine the Maximum Mass to Hover In-Ground Effect (HIGE), use the graph with the following manner:

1. Enter with OAT +14°C from bottom left and move vertically upwards, until intersecting the 6000 ft Pressure altitude line.

2. Continue horizontally to the right until intersecting the OAT +14°C line.

3. The OAT +14°C line is not intersected, thus the helicopter is not temperature-limited.

4. Therefore, the helicopter can HIGE with its maximum mass: 3200 lb.