Narrative:

I was working arrival radar at andrews tower. Mlt X was on the ILS final, and mlt Y was making a practice PAR to the same runway (19R). (WX was partial X M7V broken zf). Mlt Y had been broken out of the sequence twice just prior to this approach at the tower's request to give priority to itinerant IFR departures. On this approach he was nearing 3 mi in trail of aircraft X when I handed him off to the PAR controller who assured me he would be able to work out the spacing problem. Aircraft Y seemed to be flying the final unusually fast, and with s-turns the spacing still decreased to less than 3 mi while my attention was on an unusually heavy flow of traffic on the approach. The PAR controller and I were reluctant to breakout the practice approach (aircraft Y) because management at this facility punishes or finds fault with controllers when any complaints from users (particularly Y's squadron) are filed with the tower office whether there is merit or not. Contributing to this problem is the lack of airspace under adw's approach control and the antiquated radar used here. We are reduced to guessing aircraft speeds or playing 20 questions to institute speed control as there is no alpha-numeric capability here. The PAR controller was hindered from making the call to break out aircraft Y when he looked at my traffic and without having any idea of the downwind traffic altitude he could not determine a safe vector for Y to depart the final. For the most part we are limited to the single IFR altitude of 2000'. Supplemental information from acn 133407: in believing the WX was VFR, and he was running his traffic tight (min separation), I assumed that Y had been told to maintain visual separation from X, and now it seemed he wouldn't get his touch and go because of the full stop aircraft X. So I mentioned turns across the final on the PAR approach for Y to keep enough room so X would be clear in time for Y. He said ok, 'hand off', and I said radar contact. As soon as I realized Y's position relative to X and their speed differences I knew he would not be able to get the touch and go. On initial contact I told Y he was 2 1/2 mi in trail and to expect a 'go around'. At 5 1/2 mi from touchdown I called the tower. (Landing approval must come from them.) they said are you going to break him out and I said no, I'm going to continue then go around. At this point I relayed these intentions to Y and gave reason as the full stop X ahead. At 2-3 mi from touchdown I broke off the approach and sent mlt Y around going left of course on the PAR scope. Afterwards the temporary supervisor called on the intercom phone asking 'what the hell is going on, don't you guys know it's IFR?' not wanting to believe it at first, I asked the radar handoff controller what the WX was and he said 2 miles. I had never had legal separation from the beginning. I was, up until that time, considered a good controller.

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Original NASA ASRS Text

Title: LESS THAN STANDARD SEPARATION BETWEEN TWO MLT ACFT. OPERATIONAL ERROR. SEE OTHER ACN 133407.

Narrative: I WAS WORKING ARR RADAR AT ANDREWS TWR. MLT X WAS ON THE ILS FINAL, AND MLT Y WAS MAKING A PRACTICE PAR TO THE SAME RWY (19R). (WX WAS PARTIAL X M7V BROKEN ZF). MLT Y HAD BEEN BROKEN OUT OF THE SEQUENCE TWICE JUST PRIOR TO THIS APCH AT THE TWR'S REQUEST TO GIVE PRIORITY TO ITINERANT IFR DEPS. ON THIS APCH HE WAS NEARING 3 MI IN TRAIL OF ACFT X WHEN I HANDED HIM OFF TO THE PAR CTLR WHO ASSURED ME HE WOULD BE ABLE TO WORK OUT THE SPACING PROBLEM. ACFT Y SEEMED TO BE FLYING THE FINAL UNUSUALLY FAST, AND WITH S-TURNS THE SPACING STILL DECREASED TO LESS THAN 3 MI WHILE MY ATTN WAS ON AN UNUSUALLY HEAVY FLOW OF TFC ON THE APCH. THE PAR CTLR AND I WERE RELUCTANT TO BREAKOUT THE PRACTICE APCH (ACFT Y) BECAUSE MGMNT AT THIS FAC PUNISHES OR FINDS FAULT WITH CTLRS WHEN ANY COMPLAINTS FROM USERS (PARTICULARLY Y'S SQUADRON) ARE FILED WITH THE TWR OFFICE WHETHER THERE IS MERIT OR NOT. CONTRIBUTING TO THIS PROBLEM IS THE LACK OF AIRSPACE UNDER ADW'S APCH CTL AND THE ANTIQUATED RADAR USED HERE. WE ARE REDUCED TO GUESSING ACFT SPEEDS OR PLAYING 20 QUESTIONS TO INSTITUTE SPEED CONTROL AS THERE IS NO ALPHA-NUMERIC CAPABILITY HERE. THE PAR CTLR WAS HINDERED FROM MAKING THE CALL TO BREAK OUT ACFT Y WHEN HE LOOKED AT MY TFC AND WITHOUT HAVING ANY IDEA OF THE DOWNWIND TFC ALT HE COULD NOT DETERMINE A SAFE VECTOR FOR Y TO DEPART THE FINAL. FOR THE MOST PART WE ARE LIMITED TO THE SINGLE IFR ALT OF 2000'. SUPPLEMENTAL INFORMATION FROM ACN 133407: IN BELIEVING THE WX WAS VFR, AND HE WAS RUNNING HIS TFC TIGHT (MIN SEPARATION), I ASSUMED THAT Y HAD BEEN TOLD TO MAINTAIN VISUAL SEPARATION FROM X, AND NOW IT SEEMED HE WOULDN'T GET HIS TOUCH AND GO BECAUSE OF THE FULL STOP ACFT X. SO I MENTIONED TURNS ACROSS THE FINAL ON THE PAR APCH FOR Y TO KEEP ENOUGH ROOM SO X WOULD BE CLEAR IN TIME FOR Y. HE SAID OK, 'HAND OFF', AND I SAID RADAR CONTACT. AS SOON AS I REALIZED Y'S POSITION RELATIVE TO X AND THEIR SPEED DIFFERENCES I KNEW HE WOULD NOT BE ABLE TO GET THE TOUCH AND GO. ON INITIAL CONTACT I TOLD Y HE WAS 2 1/2 MI IN TRAIL AND TO EXPECT A 'GO AROUND'. AT 5 1/2 MI FROM TOUCHDOWN I CALLED THE TWR. (LNDG APPROVAL MUST COME FROM THEM.) THEY SAID ARE YOU GOING TO BREAK HIM OUT AND I SAID NO, I'M GOING TO CONTINUE THEN GO AROUND. AT THIS POINT I RELAYED THESE INTENTIONS TO Y AND GAVE REASON AS THE FULL STOP X AHEAD. AT 2-3 MI FROM TOUCHDOWN I BROKE OFF THE APCH AND SENT MLT Y AROUND GOING LEFT OF COURSE ON THE PAR SCOPE. AFTERWARDS THE TEMPORARY SUPVR CALLED ON THE INTERCOM PHONE ASKING 'WHAT THE HELL IS GOING ON, DON'T YOU GUYS KNOW IT'S IFR?' NOT WANTING TO BELIEVE IT AT FIRST, I ASKED THE RADAR HANDOFF CTLR WHAT THE WX WAS AND HE SAID 2 MILES. I HAD NEVER HAD LEGAL SEPARATION FROM THE BEGINNING. I WAS, UP UNTIL THAT TIME, CONSIDERED A GOOD CTLR.

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.