Air carrier X and Y airborn conflict possible less than standard separation. Possible system error.

Attributes
ACN	150559
Time
Date	199007
Day	Wed
Local Time Of Day	0601 To 1200
Place
Locale Reference	atc facility : shv
State Reference	LA
Altitude	msl bound lower : 33000 msl bound upper : 33000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zme
Operator	common carrier : air carrier
Make Model Name	Medium Large Transport, Low Wing, 2 Turbojet Eng
Flight Phase	climbout : intermediate altitude cruise other
Route In Use	enroute : on vectors enroute : direct
Flight Plan	IFR
Aircraft 2
Operator	common carrier : air carrier
Make Model Name	Any Unknown or Unlisted Aircraft Manufacturer
Flight Phase	cruise other descent other
Route In Use	enroute : on vectors enroute : direct
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Experience	flight time last 90 days : 100 flight time total : 10000 flight time type : 4800
ASRS Report	150559
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : atp
Experience	flight time last 90 days : 180 flight time total : 4000 flight time type : 800
ASRS Report	151062
Events
Anomaly	conflict : airborne less severe
Independent Detector	atc equipment other atc equipment : unspecified other controllera
Resolutory Action	controller : issued new clearance other
Consequence	Other
Miss Distance	horizontal : 30000 vertical : 2000
Supplementary
Primary Problem	ATC Human Performance
Air Traffic Incident	other

Narrative:

I was the captain of air carrier X from memphis to austin, tx, on july 1990. We were established on J-29 and level at FL330. (J-29 was our filed route of flight). About 95 mi northeast of the shreveport VOR, ZME directed me and a flight as follows, air carrier X turn 30 degree to the right, air carrier X turn 50 degree to the left. I repeated the directions of both turns. The first officer, who was flying the aircraft initiated the 30 degree right turn and then as instructed immediately began the 50 degree left turn. During our turns, ZME directed an air carrier Y flight ot turn right and then revised that clearance with instructions for air carrier Y to turn left 50 degree and descend to FL310 immediately. Air carrier Y responded to ZME. ZME then directed air carrier X to climb to FL350 immediately, that was followed by the controller saying hurry air carrier X. I acknowledged ZME, took control of the aircraft and climbed to FL350 and established on the requested heading. At that time ZME cleared air carrier X to resume normal navigation as filed. Air carrier X complied. We were handed off to ft worth center and continued to austin. Air carrier X was on course and on altitude I have no idea why there was a conflict with traffic. Supplemental information from acn 151062. I was the first officer on air carrier X. ZME instructed air carrier X to turn right 30 degree for traffic. The captain read back the instructions himself, said 'no make that a 50 degree left turn'. The captain, again read back the instructions. While we were turning to the left, ZME gave air carrier Y a turn of 50 degree to the right. He instantly corrected himself with 50 degree turn to the left and a descent to FL310. The air carrier Y pilot questioned the clearance. ZME responded 'air carrier Y left turn 50 degree and descend immediately to FL310. Air carrier X climb to FL350, hurry up!' at that time the captain took the aircraft off of autoplt and executed a climbing left turn. We leveled off at FL350 and informed ATC of our altitude and heading.

Original NASA ASRS Text

Title: ACR X AND Y AIRBORN CONFLICT POSSIBLE LESS THAN STANDARD SEPARATION. POSSIBLE SYSTEM ERROR.

Narrative: I WAS THE CAPT OF ACR X FROM MEMPHIS TO AUSTIN, TX, ON JULY 1990. WE WERE ESTABLISHED ON J-29 AND LEVEL AT FL330. (J-29 WAS OUR FILED RTE OF FLT). ABOUT 95 MI NE OF THE SHREVEPORT VOR, ZME DIRECTED ME AND A FLT AS FOLLOWS, ACR X TURN 30 DEG TO THE R, ACR X TURN 50 DEG TO THE L. I REPEATED THE DIRECTIONS OF BOTH TURNS. THE F/O, WHO WAS FLYING THE ACFT INITIATED THE 30 DEG R TURN AND THEN AS INSTRUCTED IMMEDIATELY BEGAN THE 50 DEG L TURN. DURING OUR TURNS, ZME DIRECTED AN ACR Y FLT OT TURN R AND THEN REVISED THAT CLRNC WITH INSTRUCTIONS FOR ACR Y TO TURN L 50 DEG AND DSND TO FL310 IMMEDIATELY. ACR Y RESPONDED TO ZME. ZME THEN DIRECTED ACR X TO CLB TO FL350 IMMEDIATELY, THAT WAS FOLLOWED BY THE CTLR SAYING HURRY ACR X. I ACKNOWLEDGED ZME, TOOK CTL OF THE ACFT AND CLBED TO FL350 AND ESTABLISHED ON THE REQUESTED HDG. AT THAT TIME ZME CLRED ACR X TO RESUME NORMAL NAV AS FILED. ACR X COMPLIED. WE WERE HANDED OFF TO FT WORTH CTR AND CONTINUED TO AUSTIN. ACR X WAS ON COURSE AND ON ALT I HAVE NO IDEA WHY THERE WAS A CONFLICT WITH TFC. SUPPLEMENTAL INFO FROM ACN 151062. I WAS THE F/O ON ACR X. ZME INSTRUCTED ACR X TO TURN R 30 DEG FOR TFC. THE CAPT READ BACK THE INSTRUCTIONS HIMSELF, SAID 'NO MAKE THAT A 50 DEG L TURN'. THE CAPT, AGAIN READ BACK THE INSTRUCTIONS. WHILE WE WERE TURNING TO THE L, ZME GAVE ACR Y A TURN OF 50 DEG TO THE R. HE INSTANTLY CORRECTED HIMSELF WITH 50 DEG TURN TO THE L AND A DSNT TO FL310. THE ACR Y PLT QUESTIONED THE CLRNC. ZME RESPONDED 'ACR Y L TURN 50 DEG AND DSND IMMEDIATELY TO FL310. ACR X CLB TO FL350, HURRY UP!' AT THAT TIME THE CAPT TOOK THE ACFT OFF OF AUTOPLT AND EXECUTED A CLBING L TURN. WE LEVELED OFF AT FL350 AND INFORMED ATC OF OUR ALT AND HDG.

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.