Narrative:

Iah and hou ATCT departures are all climbed to 4000 ft. Aircraft departing iah with south and southeast destinations are assigned a 120 degree heading. All aircraft departing hou to the north are assigned a 360-030 degree heading. The distance between these 2 airports is 20 mi. Iah ATCT airspace is surface to 4000 ft and a diameter of 8 mi around the airport. Hou ATCT airspace is surface to 4000 ft with a diameter of 5 mi around the airport. Most of the departures from these 2 airports are jet aircraft. You have approximately 7 mi of airspace with a closure rate of 500 KTS, this gives less than 1 min to recognize and rectify any potential conflicts. As always, when there is a critical situation in this area, iah is departing runway 33 and hou is departing runway 30. At approximately XA00 on dec/tue/02, an air carrier X B737 departed runway 33 at iah, turned left to a 120 degree heading and climbed to 4000 ft. At approximately the time an air carrier Y B737 departed runway 30 at hou, was assigned a 030 degree heading and climbed to 4000 ft. By the time both aircraft made it to their departure frequencys, an imminent situation had developed. The aircraft were on intercept vectors and separation was rapidly being lost. The departure east cpc quickly turned the air carrier X B737 to a 090 degree heading. He was only able to utilize this heading because there were no arrs at this time. Controller Y at the same time turned the air carrier B737 to a 270 degree heading. The aircraft passed within minimum IFR separation. The procedures that allow this situation to develop on a regular basis when iah is departing runway 33 and hou is departing runway 30 is that both aircraft are assigned the same altitude, 4000 ft and are assigned converging headings. Also, compounding the situation is that the I90/hou LOA allow hou ATCT to assign any heading to departures as long as that heading depart hou ATCT departure corridor. Most of the time hou ATCT assigned a 030 degree heading to aircraft departing runway 30. The actual track because of the strong north winds are 050-060 degrees. The airspace north of hou for north departure is only 6 mi wide and extends north. Aircraft on a 050-060 degree track are on a vector to depart your airspace and enter departure east's airspace almost as soon as they are xferred to your frequency. There have been ucr's and swat suggestions filed in the past over this poorly designed airspace and procedures. None of the paperwork filed has resulted in any changes. Callback conversation with reporter revealed the following information: reporter states that this runway confign is rather infrequent. The problem only exists when iah is departing runway 33 and hou departs runway 30. The towers may decide to hold on to aircraft until they have their separation criteria, then xfer communication to I90. It is during this activity, with seasonal strong winds and reduced TRACON controller reaction times, that the controller is specifically concerned with. The reporter alleges that supervisors tell the controllers to 'work it out' and this is the way we've always done it.

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Original NASA ASRS Text

Title: I90 CTLR CONCERNED ABOUT LOA PROC APPLICATIONS DURING CERTAIN IAH AND HOU ARPT RWY CONFIGNS, AND THE POTENTIAL FOR ACFT EVENTS DUE TO ALT ASSIGNMENTS.

Narrative: IAH AND HOU ATCT DEPS ARE ALL CLBED TO 4000 FT. ACFT DEPARTING IAH WITH S AND SE DESTS ARE ASSIGNED A 120 DEG HDG. ALL ACFT DEPARTING HOU TO THE N ARE ASSIGNED A 360-030 DEG HDG. THE DISTANCE BTWN THESE 2 ARPTS IS 20 MI. IAH ATCT AIRSPACE IS SURFACE TO 4000 FT AND A DIAMETER OF 8 MI AROUND THE ARPT. HOU ATCT AIRSPACE IS SURFACE TO 4000 FT WITH A DIAMETER OF 5 MI AROUND THE ARPT. MOST OF THE DEPS FROM THESE 2 ARPTS ARE JET ACFT. YOU HAVE APPROX 7 MI OF AIRSPACE WITH A CLOSURE RATE OF 500 KTS, THIS GIVES LESS THAN 1 MIN TO RECOGNIZE AND RECTIFY ANY POTENTIAL CONFLICTS. AS ALWAYS, WHEN THERE IS A CRITICAL SIT IN THIS AREA, IAH IS DEPARTING RWY 33 AND HOU IS DEPARTING RWY 30. AT APPROX XA00 ON DEC/TUE/02, AN ACR X B737 DEPARTED RWY 33 AT IAH, TURNED L TO A 120 DEG HDG AND CLBED TO 4000 FT. AT APPROX THE TIME AN ACR Y B737 DEPARTED RWY 30 AT HOU, WAS ASSIGNED A 030 DEG HDG AND CLBED TO 4000 FT. BY THE TIME BOTH ACFT MADE IT TO THEIR DEP FREQS, AN IMMINENT SIT HAD DEVELOPED. THE ACFT WERE ON INTERCEPT VECTORS AND SEPARATION WAS RAPIDLY BEING LOST. THE DEP E CPC QUICKLY TURNED THE ACR X B737 TO A 090 DEG HDG. HE WAS ONLY ABLE TO UTILIZE THIS HDG BECAUSE THERE WERE NO ARRS AT THIS TIME. CTLR Y AT THE SAME TIME TURNED THE ACR B737 TO A 270 DEG HDG. THE ACFT PASSED WITHIN MINIMUM IFR SEPARATION. THE PROCS THAT ALLOW THIS SIT TO DEVELOP ON A REGULAR BASIS WHEN IAH IS DEPARTING RWY 33 AND HOU IS DEPARTING RWY 30 IS THAT BOTH ACFT ARE ASSIGNED THE SAME ALT, 4000 FT AND ARE ASSIGNED CONVERGING HDGS. ALSO, COMPOUNDING THE SIT IS THAT THE I90/HOU LOA ALLOW HOU ATCT TO ASSIGN ANY HDG TO DEPS AS LONG AS THAT HDG DEPART HOU ATCT DEP CORRIDOR. MOST OF THE TIME HOU ATCT ASSIGNED A 030 DEG HDG TO ACFT DEPARTING RWY 30. THE ACTUAL TRACK BECAUSE OF THE STRONG N WINDS ARE 050-060 DEGS. THE AIRSPACE N OF HOU FOR N DEP IS ONLY 6 MI WIDE AND EXTENDS N. ACFT ON A 050-060 DEG TRACK ARE ON A VECTOR TO DEPART YOUR AIRSPACE AND ENTER DEP EAST'S AIRSPACE ALMOST AS SOON AS THEY ARE XFERRED TO YOUR FREQ. THERE HAVE BEEN UCR'S AND SWAT SUGGESTIONS FILED IN THE PAST OVER THIS POORLY DESIGNED AIRSPACE AND PROCS. NONE OF THE PAPERWORK FILED HAS RESULTED IN ANY CHANGES. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: RPTR STATES THAT THIS RWY CONFIGN IS RATHER INFREQUENT. THE PROB ONLY EXISTS WHEN IAH IS DEPARTING RWY 33 AND HOU DEPARTS RWY 30. THE TWRS MAY DECIDE TO HOLD ON TO ACFT UNTIL THEY HAVE THEIR SEPARATION CRITERIA, THEN XFER COM TO I90. IT IS DURING THIS ACTIVITY, WITH SEASONAL STRONG WINDS AND REDUCED TRACON CTLR REACTION TIMES, THAT THE CTLR IS SPECIFICALLY CONCERNED WITH. THE RPTR ALLEGES THAT SUPVRS TELL THE CTLRS TO 'WORK IT OUT' AND THIS IS THE WAY WE'VE ALWAYS DONE IT.

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.