Narrative:

At mdw we were cleared to takeoff runway 31C, right turn to 090 degrees and climb to 3000 ft. We were on the mdw 4 SID. The SID restricts all turns below 1300 ft MSL, and with DME equipped aircraft, turns must be made within 4 DME. The SID does not state which frequency to use in order to read DME. I now would like to state a few facts that are relevant to the situation. The aircraft had only 1 operable DME on the copilot's side. We were close to maximum takeoff weight at 97000 pounds. Winds during takeoff were 220 degrees at 15 KTS, gusting to 25 KTS. On takeoff, I flew runway heading and climbed to 1300 ft MSL and initiated my turn to 090 degrees. At about 2000 ft MSL the controller asked us to expedite to 3000 ft MSL due to traffic at 2500 ft MSL. At this point I reduced the turn rate from 25 degrees of bank to approximately 15-20 degrees of bank. I reduced the bank angle for 3 reasons: 1) to increase my climb rate to 3000 ft MSL. 2) to increase my copilot's field of vision so he could search for the traffic that we had been advised of. 3) and finally, to increase my airspeed to zero degrees flaps maneuvering speed. Upon reaching 3000 ft MSL, I continued my right turn to 090 degrees of heading. At no time did we receive a TCASII alert or warning, nor did I deviate from my assigned altitude or heading. We were handed off to the next controller and he assigned us a new heading of 060 degrees. The new controller also made the statement that we had not complied with the mdw 4 departure restrs. Nothing else was said and our flight continued normally. In my professional judgement, I did what had to be done in order to meet the requirements of the SID, controllers, and aircraft performance. At no time was my aircraft and my passenger in jeopardy. My only question is about the SID. The 4 DME requirement does not state which frequency to use in order to read the DME. Is it the ILS runway 31C DME? And if so, wouldn't that DME reading be wrong due to the placement of the localizer and the threshold of runway 31C. Is 4 DME from the center of the airport? And finally, do the controllers take into consideration the effect of strong winds on the turn performance of aircraft?

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Original NASA ASRS Text

Title: MLG FLC TURNS BEYOND 4 DME LIMIT DESCRIBED BY SID.

Narrative: AT MDW WE WERE CLRED TO TKOF RWY 31C, R TURN TO 090 DEGS AND CLB TO 3000 FT. WE WERE ON THE MDW 4 SID. THE SID RESTRICTS ALL TURNS BELOW 1300 FT MSL, AND WITH DME EQUIPPED ACFT, TURNS MUST BE MADE WITHIN 4 DME. THE SID DOES NOT STATE WHICH FREQ TO USE IN ORDER TO READ DME. I NOW WOULD LIKE TO STATE A FEW FACTS THAT ARE RELEVANT TO THE SIT. THE ACFT HAD ONLY 1 OPERABLE DME ON THE COPLT'S SIDE. WE WERE CLOSE TO MAX TKOF WT AT 97000 LBS. WINDS DURING TKOF WERE 220 DEGS AT 15 KTS, GUSTING TO 25 KTS. ON TKOF, I FLEW RWY HDG AND CLBED TO 1300 FT MSL AND INITIATED MY TURN TO 090 DEGS. AT ABOUT 2000 FT MSL THE CTLR ASKED US TO EXPEDITE TO 3000 FT MSL DUE TO TFC AT 2500 FT MSL. AT THIS POINT I REDUCED THE TURN RATE FROM 25 DEGS OF BANK TO APPROX 15-20 DEGS OF BANK. I REDUCED THE BANK ANGLE FOR 3 REASONS: 1) TO INCREASE MY CLB RATE TO 3000 FT MSL. 2) TO INCREASE MY COPLT'S FIELD OF VISION SO HE COULD SEARCH FOR THE TFC THAT WE HAD BEEN ADVISED OF. 3) AND FINALLY, TO INCREASE MY AIRSPD TO ZERO DEGS FLAPS MANEUVERING SPD. UPON REACHING 3000 FT MSL, I CONTINUED MY R TURN TO 090 DEGS OF HDG. AT NO TIME DID WE RECEIVE A TCASII ALERT OR WARNING, NOR DID I DEVIATE FROM MY ASSIGNED ALT OR HDG. WE WERE HANDED OFF TO THE NEXT CTLR AND HE ASSIGNED US A NEW HDG OF 060 DEGS. THE NEW CTLR ALSO MADE THE STATEMENT THAT WE HAD NOT COMPLIED WITH THE MDW 4 DEP RESTRS. NOTHING ELSE WAS SAID AND OUR FLT CONTINUED NORMALLY. IN MY PROFESSIONAL JUDGEMENT, I DID WHAT HAD TO BE DONE IN ORDER TO MEET THE REQUIREMENTS OF THE SID, CTLRS, AND ACFT PERFORMANCE. AT NO TIME WAS MY ACFT AND MY PAX IN JEOPARDY. MY ONLY QUESTION IS ABOUT THE SID. THE 4 DME REQUIREMENT DOES NOT STATE WHICH FREQ TO USE IN ORDER TO READ THE DME. IS IT THE ILS RWY 31C DME? AND IF SO, WOULDN'T THAT DME READING BE WRONG DUE TO THE PLACEMENT OF THE LOC AND THE THRESHOLD OF RWY 31C. IS 4 DME FROM THE CTR OF THE ARPT? AND FINALLY, DO THE CTLRS TAKE INTO CONSIDERATION THE EFFECT OF STRONG WINDS ON THE TURN PERFORMANCE OF ACFT?

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.