Narrative:

We were in good visibility conditions and had the oakland airport in sight from over livermore. Over sunol gap at 7000' we were cleared for the visibility approach oak runway 29, cross 6 DME below 3000' and above 2000'. No mention of traffic at this point. At about 15 mi out we were asked for 'best rate' through 3000'. Still no explanation of why. We increased our rate but did not throw out all the drag for an uncomfortable descent. At about 12.5 DME we were about 4500' reaching the 3000'/6 DME restriction well early when we were told to expedite to 3000', traffic 12:30, 3 mi, 3500'. As the captain pushed it over I noted that we were well above him and wondered why we were instructed to descend through his altitude. The first officer spotted him first, below us in a climbing left turn. We were 1/2-3/4 mi apart. We probably pushed over a little more, but our flight paths at the time of sighting would have missed each other. The other aircraft was a twin turbo-propeller. I saw the belly briefly, but not long enough to identify it. If we had not got the expedited descent our paths would have been head on or very close. The thing that bothers me most was ATC's handling of the conflict. They did not advise us of the traffic until we were 30-45 seconds apart. Also, I think the controller had such a mind set to get us below the the other guy that even when the conflict became significant (and we were first advised) he instructed us to descend through the altitude of head on climbing traffic that was still about 1000' below us. It was close enough that all 3 of us were upset with the way it was handled. I was only a developmental controller at the center, but I don't remember any approved procedure to climb/descend head on traffic through each others altitudes at close range. I would have been much more comfortable if they had stopped the twin at 3500' and us at 4500' until passing, even if we then were too high and had to go around the pattern at oakland. I think this controller should review the incident and try to develop other more suitable solutions to use in the future. Also, the twin should not have been allowed to make his climbing left turn (probably off hayward) head on into the oak localizer, especially with traffic (us) approaching.

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Original NASA ASRS Text

Title: WHILE MAKING A VISUAL APCH, LGT HAS A CLOSE ENCOUNTER WITH A CLIMBING LIGHT TWIN.

Narrative: WE WERE IN GOOD VIS CONDITIONS AND HAD THE OAKLAND ARPT IN SIGHT FROM OVER LIVERMORE. OVER SUNOL GAP AT 7000' WE WERE CLRED FOR THE VIS APCH OAK RWY 29, CROSS 6 DME BELOW 3000' AND ABOVE 2000'. NO MENTION OF TFC AT THIS POINT. AT ABOUT 15 MI OUT WE WERE ASKED FOR 'BEST RATE' THROUGH 3000'. STILL NO EXPLANATION OF WHY. WE INCREASED OUR RATE BUT DID NOT THROW OUT ALL THE DRAG FOR AN UNCOMFORTABLE DSNT. AT ABOUT 12.5 DME WE WERE ABOUT 4500' REACHING THE 3000'/6 DME RESTRICTION WELL EARLY WHEN WE WERE TOLD TO EXPEDITE TO 3000', TFC 12:30, 3 MI, 3500'. AS THE CAPT PUSHED IT OVER I NOTED THAT WE WERE WELL ABOVE HIM AND WONDERED WHY WE WERE INSTRUCTED TO DSND THROUGH HIS ALT. THE F/O SPOTTED HIM FIRST, BELOW US IN A CLBING L TURN. WE WERE 1/2-3/4 MI APART. WE PROBABLY PUSHED OVER A LITTLE MORE, BUT OUR FLT PATHS AT THE TIME OF SIGHTING WOULD HAVE MISSED EACH OTHER. THE OTHER ACFT WAS A TWIN TURBO-PROP. I SAW THE BELLY BRIEFLY, BUT NOT LONG ENOUGH TO IDENT IT. IF WE HAD NOT GOT THE EXPEDITED DSNT OUR PATHS WOULD HAVE BEEN HEAD ON OR VERY CLOSE. THE THING THAT BOTHERS ME MOST WAS ATC'S HANDLING OF THE CONFLICT. THEY DID NOT ADVISE US OF THE TFC UNTIL WE WERE 30-45 SECS APART. ALSO, I THINK THE CTLR HAD SUCH A MIND SET TO GET US BELOW THE THE OTHER GUY THAT EVEN WHEN THE CONFLICT BECAME SIGNIFICANT (AND WE WERE FIRST ADVISED) HE INSTRUCTED US TO DSND THROUGH THE ALT OF HEAD ON CLBING TFC THAT WAS STILL ABOUT 1000' BELOW US. IT WAS CLOSE ENOUGH THAT ALL 3 OF US WERE UPSET WITH THE WAY IT WAS HANDLED. I WAS ONLY A DEVELOPMENTAL CTLR AT THE CTR, BUT I DON'T REMEMBER ANY APPROVED PROC TO CLB/DSND HEAD ON TFC THROUGH EACH OTHERS ALTS AT CLOSE RANGE. I WOULD HAVE BEEN MUCH MORE COMFORTABLE IF THEY HAD STOPPED THE TWIN AT 3500' AND US AT 4500' UNTIL PASSING, EVEN IF WE THEN WERE TOO HIGH AND HAD TO GO AROUND THE PATTERN AT OAKLAND. I THINK THIS CTLR SHOULD REVIEW THE INCIDENT AND TRY TO DEVELOP OTHER MORE SUITABLE SOLUTIONS TO USE IN THE FUTURE. ALSO, THE TWIN SHOULD NOT HAVE BEEN ALLOWED TO MAKE HIS CLBING L TURN (PROBABLY OFF HAYWARD) HEAD ON INTO THE OAK LOC, ESPECIALLY WITH TFC (US) APCHING.

Data retrieved from NASA's ASRS site as of July 2007 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.