Enter on TRIP DISTANCE scale at 2400 NM … go vertically up to the WIND REF line – make a pencil mark ...

... adjust to 25 kt TAIL WIND condition … so follow the adjustment curves down and left to 25 kt TAILWIND … make a pencil mark … now draw a line vertically UP through the 2 sets of PRESSURE ALTITUDE curves.

From the first set of PRESSURE ALTITUDE curves … find 31000ft (interpolate between 29000 and 33000) … from this point, go right horizontally to the LANDING WEIGHT REFERENCE line … make a pencil mark.

Now adjust to the LW condition 52000kg … there are 2 curves … the dashed line, which you would follow IF you were at 37000ft, and the solid line, which you would follow IF you were at 10000ft … so you need to interpolate between the two. This is a bit of a fiddle – but if you just draw both adjustment lines (37000ft and 10000ft – the interpolation will become straight forward – look at the answers – the spread is quite reasonable.

For trip time, go to the TOP PRESSURE ALTITUDE curves … 29 & ABOVE … across to the ISA DEVIATION REF LINE - make a pencil mark … now adjust to your condition ISA-10⁰C, so right and up to ISA -10 … now read the scale.