Had it once on a md 80 off 34 zrh..
Not forecast but mate reported it just before we departed - he was airborne off 28.- 23 knots cross.
We lost 30 knots around 1000ft but had a significant temperature increase..which meant we were way outside our take off calculation.
Went firewall and pitch but speed continued to decrease and therefore on the backside of the drag curve.
Skipper ignored my speed calls and with the black forest looming in the darkness I forced the nose down...and we started accelerating. Climb performance slowly returned.
Cause large pool of very cold air over the airfield but a warm front blowing over the top.
Besides one partial report no forecast to stop us going.
Last edited by blind pew; 7th May 2013 at 17:37.