Higher not always better?
Perhaps not the best place to be asking this, but couldn't figure where else to post it.
Yesterday flying from Bombay to Calcutta at FL330 had tailwind of about 40 knot. Over Nagpur, I asked the Captain if I may request for FL390 so we get more tail wind. The GS at this time was about 490 knot.
He asked if it would really be worth it... And asked me to request the controller for a climb. Which we did. Climb to FL390.
This time there was a tailwind of about 90 knot. I thought it would make me reach the destination a tad bit faster. To my surprise we lost 5 minutes and no change on the fuel. The GS at this time was about 515 knot
We were also, maintaining a constant M.78....
How did I lose 5 minutes despite being higher and in a stronger tailwind??