Narrative:

Takeoff runway 33C at mem. Heavy DC10 departed runway 36R, 5 mi separation. Given 060 degree heading for J29. Assigned 230 KTS for spacing on turn. Encountered wake turbulence from DC10. Increased speed for ctlability. Told ATC about airspeed. He said he had 5 mi separation. Obviously not enough this time. Would recommend that aircraft departing runway 36C not be given heading across heavy aircraft path to join airway. Advised ATC that speed was increased for these reasons. Callback conversation with reporter revealed the following information: reporter stated their aircraft was B757 and they departed 5 mi behind a DC10 that was off a parallel runway on the right. Pilot said it appeared they were slowly overtaking the DC10 and were instructed to slow to 220 KTS from 250 KTS. At the same time they were given a turn to the right behind the DC10 for spacing. He said almost immediately they encountered severe wake turbulence and he increased his speed back to 250 KTS which eventually took them back into smooth air.

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Original NASA ASRS Text

Title: B757 DEPARTING MEM ENCOUNTERED SEVERE WAKE TURB AFTER DEPARTING 5 MI BEHIND A DC10 THAT DEPARTED OFF A PARALLEL RWY.

Narrative: TKOF RWY 33C AT MEM. HVY DC10 DEPARTED RWY 36R, 5 MI SEPARATION. GIVEN 060 DEG HDG FOR J29. ASSIGNED 230 KTS FOR SPACING ON TURN. ENCOUNTERED WAKE TURB FROM DC10. INCREASED SPD FOR CTLABILITY. TOLD ATC ABOUT AIRSPD. HE SAID HE HAD 5 MI SEPARATION. OBVIOUSLY NOT ENOUGH THIS TIME. WOULD RECOMMEND THAT ACFT DEPARTING RWY 36C NOT BE GIVEN HDG ACROSS HVY ACFT PATH TO JOIN AIRWAY. ADVISED ATC THAT SPD WAS INCREASED FOR THESE REASONS. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: RPTR STATED THEIR ACFT WAS B757 AND THEY DEPARTED 5 MI BEHIND A DC10 THAT WAS OFF A PARALLEL RWY ON THE R. PLT SAID IT APPEARED THEY WERE SLOWLY OVERTAKING THE DC10 AND WERE INSTRUCTED TO SLOW TO 220 KTS FROM 250 KTS. AT THE SAME TIME THEY WERE GIVEN A TURN TO THE R BEHIND THE DC10 FOR SPACING. HE SAID ALMOST IMMEDIATELY THEY ENCOUNTERED SEVERE WAKE TURB AND HE INCREASED HIS SPD BACK TO 250 KTS WHICH EVENTUALLY TOOK THEM BACK INTO SMOOTH AIR.

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.