Jet Stream

Recently we flew to Perth for a holiday. The flying time from Tullamarine to Perth took just on four hours in a Boeing 737, because we were travelling headlong into the prevailing westerly airstream. At 33,000 feet or 10,000 metres the headwinds would have been over 180 kilometres per hour at the time we went.

On our return flight it only took 2 hours 51 minutes from Perth to Melbourne. How was this possible? It wasn’t only due to the expected strong tail wind – it was the navigator’s expertise in using the jet stream.

Several narrow jet streams of very fast flowing air are continually circling the planet. They often bear no resemblance at all to the pattern of winds blowing at the surface. Normally they are not shown on the weather map, but on the graphic you can see where they were located at the time of our return flight.

Streaming mainly eastwards at sometimes over 500 kilometres per hour, they can provide a money-saving tailwind for the airlines and a rapid, if sometimes bumpy, flight home from Perth. We reached a top speed of 985 kilometres per hour and were home over half an hour earlier than scheduled.

Of course we still had to wait half an hour for our baggage and to get to our car.