Narrative:

Mlt X, SID departure northbound, level 10000', requested climb for WX. I was unable to issue climb, but approved a deviation for WX, left or right. Mlt X was subsequently transferred (communications and radar) to center, level 10000'. Mlt Y, same SID departure, northbound, level 10000', 6-7 mi, intrail of mlt X. Mlt Y requested climb for WX. Again I was unable to climb but approved a deviation to the left only. Mlt X started a right turn towards an en route fix (cew) as filed, but continued a right turn to a 270 degree turn coming behind mlt Y within 2.5 mi, both at 10000'. Pilot of mlt X told center controller that approach had approved a deviation to the south. I advised center controller to issue mlt X a turn southwest (240 degrees) at 10000' and radar contact. Mlt Y was turned right direct cew and switched to center. Mlt X was give same instructions and switched to center also. Recommend: controller should be more specific when issuing deviation approval, ie, only so many degrees left or right for set amount of time, etc. Also ensure aircraft is on course before changing radio to another facility, or advise of deviation. Flight crews should not expect that they can deviate greater than 30-60 degrees west/O further clearance to do so. Surely not a course reversal or 270/360 degrees! Callback conversation with reporter revealed the following: when reporter advised his supervisor that there had been a problem with sep between mlt X and mlt Y, the facility removed reporter from operational duties and started an investigation. An ntap showed that the sep between the 2 aircraft was 2.5 mi at the same altitude. The facility determined that an operational error did not occur, however because the second mlt was on approach control frequency and there was legal course divergence sep, reporter was counseled by facility mgt for not being more specific in his instructions to mlt X and mlt Y when allowing the WX deviations. The controller, in effect, gave the 2 flight crews carte blanche by allowing a non specific deviation for WX. During this incident, both aircraft remained in pns airspace while mlt X went to ZJX frequency and back to pns frequency during the turn for WX. Mlt Y stayed on pns frequency for the duration of the incident. Reporter is correct when he says controllers should be specific when they allow deviations for WX when more than 1 aircraft is involved.

Google
 

Original NASA ASRS Text

Title: MLT MADE 270 DEGREE TURN WHILE DEVIATING FOR WX AND NEARLY CAUSED LOSS OF SEPARATION WITH FOLLOWING MLT.

Narrative: MLT X, SID DEP NBND, LEVEL 10000', REQUESTED CLB FOR WX. I WAS UNABLE TO ISSUE CLB, BUT APPROVED A DEVIATION FOR WX, LEFT OR RIGHT. MLT X WAS SUBSEQUENTLY TRANSFERRED (COMS AND RADAR) TO CENTER, LEVEL 10000'. MLT Y, SAME SID DEP, NBND, LEVEL 10000', 6-7 MI, INTRAIL OF MLT X. MLT Y REQUESTED CLB FOR WX. AGAIN I WAS UNABLE TO CLB BUT APPROVED A DEVIATION TO THE LEFT ONLY. MLT X STARTED A RIGHT TURN TOWARDS AN ENRTE FIX (CEW) AS FILED, BUT CONTINUED A RIGHT TURN TO A 270 DEG TURN COMING BEHIND MLT Y WITHIN 2.5 MI, BOTH AT 10000'. PLT OF MLT X TOLD CENTER CTLR THAT APCH HAD APPROVED A DEVIATION TO THE S. I ADVISED CENTER CTLR TO ISSUE MLT X A TURN SW (240 DEGS) AT 10000' AND RADAR CONTACT. MLT Y WAS TURNED RIGHT DIRECT CEW AND SWITCHED TO CENTER. MLT X WAS GIVE SAME INSTRUCTIONS AND SWITCHED TO CENTER ALSO. RECOMMEND: CTLR SHOULD BE MORE SPECIFIC WHEN ISSUING DEVIATION APPROVAL, IE, ONLY SO MANY DEGS LEFT OR RIGHT FOR SET AMOUNT OF TIME, ETC. ALSO ENSURE ACFT IS ON COURSE BEFORE CHANGING RADIO TO ANOTHER FAC, OR ADVISE OF DEVIATION. FLT CREWS SHOULD NOT EXPECT THAT THEY CAN DEVIATE GREATER THAN 30-60 DEGS W/O FURTHER CLRNC TO DO SO. SURELY NOT A COURSE REVERSAL OR 270/360 DEGS! CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING: WHEN RPTR ADVISED HIS SUPVR THAT THERE HAD BEEN A PROB WITH SEP BTWN MLT X AND MLT Y, THE FAC REMOVED RPTR FROM OPERATIONAL DUTIES AND STARTED AN INVESTIGATION. AN NTAP SHOWED THAT THE SEP BTWN THE 2 ACFT WAS 2.5 MI AT THE SAME ALT. THE FAC DETERMINED THAT AN OPERROR DID NOT OCCUR, HOWEVER BECAUSE THE SECOND MLT WAS ON APCH CTL FREQ AND THERE WAS LEGAL COURSE DIVERGENCE SEP, RPTR WAS COUNSELED BY FAC MGT FOR NOT BEING MORE SPECIFIC IN HIS INSTRUCTIONS TO MLT X AND MLT Y WHEN ALLOWING THE WX DEVIATIONS. THE CTLR, IN EFFECT, GAVE THE 2 FLT CREWS CARTE BLANCHE BY ALLOWING A NON SPECIFIC DEVIATION FOR WX. DURING THIS INCIDENT, BOTH ACFT REMAINED IN PNS AIRSPACE WHILE MLT X WENT TO ZJX FREQ AND BACK TO PNS FREQ DURING THE TURN FOR WX. MLT Y STAYED ON PNS FREQ FOR THE DURATION OF THE INCIDENT. RPTR IS CORRECT WHEN HE SAYS CTLRS SHOULD BE SPECIFIC WHEN THEY ALLOW DEVIATIONS FOR WX WHEN MORE THAN 1 ACFT IS INVOLVED.

Data retrieved from NASA's ASRS site as of August 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.