CAPT OF A CANADAIR CL65 REGIONAL JET FAILED TO STOP HIS HIGH SPD DSCNT AT THE 10000 FT ALT IN TIME TO MEET THE 250 KT SPD RESTR; BUT ALMOST ON HIS WAY TO 9000 FT. SINCE HE HAD VERY LITTLE EXPERIENCE IN THE ACFT; HE SOLICITED THE HELP OF THE RPTING FO WHO DID GIVE HIM ALT READOUTS AND INSTRUCTED HIM TO DISENGAGE THE AUTOPLT AND PITCH UP TO SLOW DOWN.

Narrative

THE CAPT I WAS FLYING WITH HAD ONLY ABOUT 35 HRS IN TYPE AND TOLD ME THIS VERY HONESTLY IN HIS BRIEFING BEFORE OUR FIRST LEG. HE ASKED THAT I WATCH CLOSELY AND TELL HIM IF I SAW ANYTHING ABOUT TO GO AWRY. THROUGHOUT THE TRIP; WE WORKED AS A TEAM TO HELP EACH OTHER. IT JUST SO HAPPENED THAT ON THIS LEG HE WAS THE PF AND I NOTICED AN IMPENDING AIRSPD PROB. PHL APCH HAD CLRED US TO DSND FROM SOME ALT ABOVE 10000 FT DOWN THROUGH 10000 FT TO 9000 FT. WE WERE COMPLETING THE DSCNT CHKLIST WHEN I LOOKED UP AND SAW US DSNDING THROUGH 11000 FT FOR 9000 FT AND STILL AT CRUISE/HIGH SPD OF APPROX 320 KIAS. I IMMEDIATELY SAID; 'APCHING 10000 FT; WE NEED TO SLOW TO 250 KTS.' AT THAT POINT; THE CAPT DIALED A SLOWER DSCNT RATE INTO THE AUTOPLT IN ORDER TO PITCH US UP AND SLOW. PWR WAS NEAR IDLE. AS THE AUTOPLT SLOWLY PITCHED UP; I SAW THAT MUCH MORE AGGRESSIVE CORRECTIVE ACTION WAS GOING TO BE REQUIRED NOT TO BUST THE 250 KIAS SPD LIMIT AT 10000 FT. AT 10500 FT I SAID; 'APCHING 10000 FT; RECOMMEND DISENGAGE AUTOPLT AND PITCH UP.' HE DID; AND WE SLOWED NICELY TO ABOUT 250 KTS IN THE AREA OF 10000 FT. ATC HAD NO COMPLAINTS.