Some pilots contend that a strong headwind is not a concern because the lost time will be gained on the return journey, when benefitting from the tailwind. The truth is, for a constant wind situation, the effects of a headwind cannot be reversed by the tailwind on the return trip. A simple calculation will end the discussion on this subject.

For illustration, assume a 180 nm trip, a 60 kts headwind, and an aircraft that cruises at 150 kts TAS.

The ground speed into the headwind will be 150 kts minus 60 kts wind or 90 kts. Time to fly the 180 nm will be 180 nm / 90 kts ground speed, or 2.0 hrs.

For the return trip, ground speed will be 150 kts plus 60 kts tailwind, or 210 kts. Time to fly the return trip will be 180 nm / 210 kts, or 0.86 hrs.

Total flight time with this wind situation = 2.0 hrs + 0.86 hrs = 2.86 hrs.

Now consider the no-wind journey. Still 180 nm each way, total 360 nm. TAS of aircraft is 150 kts. Therefore total round-trip time, with no wind, will be 360 nm / 150 kts TAS, or 2.4 hours — 0.46 hrs shorter than flying with the headwind and tailwind.

Try the calculation for any distances, any TAS, and any wind speed. The results remain the same. The effects of a headwind can not be overcome by the same tailwind.

The simple reason; you stay longer in the punishment of the headwind than in the benefit of the shorter time in the tailwind ......

Johan van Wyk