ACR DSNDING TO CROSS WITH SPD AND ALT RESTRICTION. MISSES BOTH.

Narrative

THE FO WAS FLYING AND DSNDING TO CROSS BRONC INTXN (15 MI E OF GARDNER VOR). AT 11000 AT 250 KTS AS ASSIGNED BY ATC. IT WAS EARLY IN THE MORNING AND LITTLE TFC; OR AT LEAST LITTLE ATC TALKING. WE WERE GOING TO BE EARLY AND THE FLT ATTENDANTS ADVISED THEY WERE STILL PICKING UP THE CABIN. THE FO SLOWED DOWN SINCE WE WERE EARLY. AFTER THE FLT ATTENDANTS LEFT THE FLT DECK WE REALIZED THAT WE WERE HIGH. SINCE THERE WAS LITTLE RADIO TFC; AND WE HAD ONE OF THE FEW ACFT WITHOUT TCASII THE FO PICKED UP SPD TO MAKE XING ALT. THE OMEGA'S SHOWED THE FIX TO BE FURTHER THAN IT WAS ACCORDING TO DME. WHEN CTR HANDED OFF TO BOS APCH HE ASKED SPD WE WERE REDUCING THROUGH ON THE WAY TO 250. IT WAS 265 AND RAPIDLY COMING BACK BUT THE OMEGA SHOWED US 2 MI TO GO. THEN I REALIZED THE DME SHOWED US PAST BRONC. NOTHING MORE WAS SAID REGARDING SPD BUT IT MADE ME REALIZE HOW MUCH WE HAD COME TO USE TCASII FOR SPACING INTO HUB/HIGH DENSITY AREAS; (IE; IF NOONE WAS 15 OR 20 MI IN FRONT OF US WE KNOW WE CAN USUALLY GET APPROVAL TO KEEP SPD UP). FACTORS: DISTRS. CONFLICTING INFO. DEPENDENCE ON EQUIP/TECHNOLOGY.