WDB CREW DEPARTED IN ICING CONDITIONS. IN AN ATTEMPT TO MAKE A XING RESTR THE CAPT DIRECTED THE FO TO PULL THE NOSE UP; AND THEN RETRACTED THE SLATS. ACFT STALL RESULTED.

Narrative

DEPART MXP RWY 35L APPROX 540000 LBS. RMG 16F DEP AOSTA 8 J TRANSITION. MODERATE ICING RPTED UNTIL 11000 FT. WE PERFORMED A FULL PWR TKOF WITH ENG ANTI-ICE ON. IACO-A DEP NOISE ABATEMENT DEP WITH ENG ANTI-ICE ON SOMETIME AFTER TKOF. WE DELAYED FLAP RETRACTION UNTIL FIRST FEW XING RESTRS WERE COMPLIED WITH. THE CAPT WISHED TO DELAY SLAT RETRACTION UNTIL FURTHER RESTRS WERE COMPLIED WITH. DURING CLBOUT I SUGGESTED 3 TIMES WE ACCELERATE TO SLAT RETRACTION SPD AND RETRACT THE SLATS. AS IT WAS OBVIOUS IF WE ACCELERATE WE WOULD NOT MAKE THE XING RESTRS I SUGGESTED 1 TURN IN HOLDING. AT MY SECOND REQUEST THE CAPT SEEMED TO AGREE; COMMANDED THAT WE ACCELERATE AND ASKED FOR A TURN IN HOLDING. APPROX 30 KTS BELOW SLAT RETRACTION SPD THE CAPT CHANGED HIS MIND AND COMMANDED THAT THE NOSE OF THE ACFT BE RAISED AND CANCELED THE HOLDING CLRNC. AT THIS POINT AT 15000 FT I STATED WE NEEDED TO CLEAN THE ACFT UP. THE CAPT VERY FORCEFULLY STATED THIS IS HOW I WANT YOU TO DO IT. (SLATS EXTENDED.) AS WE CLBED THROUGH 18000 FT MILAN CTL CALLED US AND STATED WE WERE FLYING INTO A MINIMUM RADAR ALT OF 19000 FT. AT THIS TIME THE CAPT REQUESTED A TURN IN HOLDING. ATC AUTH A R TURN TOWARD THE N. WE EXECUTED THIS TURN WITH THE SLATS EXTENDED AS THIS WAS THE DESIRE OF THE CAPT. AT 20000 FT MSL THE CAPT COMMANDED THE FO TO LOWER THE NOSE TO SLAT RETRACTION SPD. 10 KTS ABOVE SLAT RETRACTION SPD THE SLATS WERE RETRACTED. IMMEDIATELY UPON SLAT RETRACTION PRONOUNCED BUFFET OCCURRED AND THE ACFT WALLOWED PITCHED ABOUT. THE SLATS WERE EXTENDED AND THE BUFFETING CEASED. THE SLATS WERE AGAIN RETRACTED AT A HIGHER SPD; BUFFETING RESUMED. STALL RECOVERY PROCS WERE SUCCESSFULLY EXECUTED WITHOUT A LOSS OF ALT. I BELIEVE THE BUFFET WAS CAUSED BY PROLONGED EXPOSURE TO MODERATE ICING EXPOSURE DUE TO THE HIGH PITCH ATTITUDE AND SLOW SPD.