On Apr 2, 9:18 pm, "John Halpenny" wrote:
On Apr 2, 5:33 pm, "Vaughn Simon"
wrote:

"Marco Leon" wrote in message

m...

Air does not "stick" to an airframe enough to change the ambient temperature
of a given area no matter how small.

No, but everyone who has ever studied for their Private written knows that
the wake of an aircraft is accelerated down. So the passage of an aircraft
would cause a very temporary downward flow of air. Would the effect be enough
to noticeably change local temperatures? I doubt it; but who the hell am I?

What time of day does he go by? I could see the downwash mixing up
the air, and if there is a hot surface layer this could cool it.

As an example of downwash changing the temperature, I have heard
helicopter pilot stories about 'frost flights' at strawberry farms.
The task is to spend the night at the farm, and if the frost alarm
goes off in the wee hours you have to fly low over the fields in the
dark until the air is stirred up and the frost danger goes away. It
apparently is very effective in preventing frost damaged berries.

John Halpenny


This has been done with fixed-wing airplanes, too. An airliner
on approach can't help but drive down air from a couple hundred feet
up. Problem with that, of course, is that the OP says his dad notices
this on the drive to work, presumably in the morning, and the air
aloft will be warmer rather than colder at that time. The nocturnal
inversion is still in play in the morning, before the surface heats
up. It's that warmer air the helicopters or other craft are driving
down at night into the orchards or vineyards or citrus groves.

Dan