NMAC ACR MLG AND GA SMA.

Narrative

DESCENDING ON APPROACH INTO IAH ON THE DAISETTA SEVEN ARRIVAL THE MLG ON WHICH I WAS THE FIRST OFFICER JUST MISSED FLYING INTO A SMALL SMA. IAH APPROACH HAD POINTED THE SMA OUT TO US A MINUTE OR TWO BEFORE AS VFR TFC 11 O'CLOCK; 10 MILES (I THINK) 8300' ALTITUDE NOT VERIFIED. I IMMEDIATELY SIGHTED THE ACFT AND TOLD APPROACH CONTROL WE HAD THE ACFT IN SIGHT AND THAT THE 8300' SEEMED ACCURATE. I CONTINUED TO LOOK AT THE ACFT AS WE DESCENDED FROM 10000'. I ASKED THE CAPTAIN IF HE HAD THE ACFT IN SIGHT. HE SAID YES. AS THE ACFT CONVERGED; I AGAIN ASKED THE CAPTAIN IF HE HAD THE TFC. HE AGAIN SAID YES. IT IS TOUGH TO ESTIMATE DISTANCES UP CLOSE--BUT AT ONE-QUARTER MILE--A FEW SECONDS AFTER THE SECOND TIME I ASKED THE CAPTAIN IF HE HAD THE OTHER ACFT; I SAID 'WELL LET'S DO SOMETHING.' HE SAID 'NOW HOLD YOUR HORSES.' ABOUT FIVE (5) SECONDS LATER HE ADDED POWER--SLOWED OUR DESCENT--AND BANKED SLIGHTLY TO THE RIGHT. WE WOULD HAVE LET THE ACFT WITHOUT EVADING. WE MISSED BY ABOUT 200'. LATER THE CAPTAIN SAID SOMETHING ABOUT NOT REALIZING THE OTHER ACFT WAS APPROACHING (IT WAS HEADED NE--WE SW EVEN THOUGH I HAD SPECIFICALLY ASKED THE CTLR WHO ANSWERED 'NE.' THE CAPTAIN--AN IOE CHECK AIRMEN TOOK AN UNNECESSARY CHANCE. IF THE OTHER PILOT HAD PANICKED WE COULD HAVE COLLIDED. THE INCIDENT OCCURRED DUE TO THE CAPTAIN'S FRAME OF MIND. I DON'T KNOW WHAT FRAME OF MIND ALLOWS SOMEONE TO FLY AN AIRLINER THAT CLOSE TO ANOTHER PLANE.