What makes for the time difference?

We have been having an argument with my husband for some time now about why do planes take 8 hours to get to Europe but 9 hours to get back. He says it's the head/tail wind, I say it's the Earth spinning. Care to take sides?

Sorry, hubby is right. since the air mass around the earth spins with the earth, rotation has no effect on flying. The jet stream does though, and it is generally blowing mostly east.

prevailing winds.

It's the jet stream. Trans-Atlantic flights can take advantage of the jet stream to reduce flight time significantly when flying with the stream. The ground speed is the sum of the wind speed plus the aircraft speed. Flying into the wind slows your ground speed by the speed of the wind.

Winds.... but I will tell ya now... just tell him a bunch of people said it is due to earth rotation....I mean.... who is a wife who can't con her husband!

Anything in the atmosphere spins with the earth at the same rate.
To keep up with the earth spin means traveling at twice the speed of sound, and since Concorde has been retired, there are no airliners that can fly at that speed.
So, you are wrong, your husband is right. It is the wind.

Your husband is right. If it was the spin of the Earth, it should take LONGER time to go to Europe than back.

Hubby is right.

, if your figures are right, and they sound correct, the west to east flight will be shorter as the prevailing jet stream flow is in that direction Tail wind, this also servs to slow dow the aircraft flying from east to west, head wind

winds are a factor but so can be
the actual track or course taken.
good question
typically east to west over the Atlantic
travel more southerly