2003-07 · NASA ASRS report 587723
ENRTE LR24 EXPERIENCE POSSIBLE LOSS OF SEPARATION IN ZAB AIRSPACE.
WE RECEIVED A MESSAGE FROM ZLA THAT WE HAD BEEN INVOLVED IN A POTENTIAL PLTDEV BECAUSE OF A LOSS OF SEPARATION DURING OUR TIME WITH ZAB AND THAT THEY REQUESTED WE CALL WHEN WE GOT ON THE GND. MY FO AND I SURMISED THAT THE ONLY POTENTIAL CONFLICT WAS ON CLBOUT WHEN WE RECEIVED A TIME RESTR CLB TO FL350 FROM FL310. THE CTLR QUERIED OUR ASCENT TIME TO FL350 AND UPON OUR CONCURRENCE; THE FO REPLIED THAT WE COULD BE LEVEL IN 2 MINS. THE CTLR RESPONDED WITH A CLRNC TO BE LEVEL AT FL350 AND GAVE US A ZULU TIME AND FOLLOWED THAT UP WITH THE CURRENT CTR TIME. THE FO REPLIED 'TO BE AT FL350 IN 2 MINS OR LESS.' AT WHICH TIME HE PLACED HIS CLOCK IN 'ET' MODE AND BEGAN THE COUNT UP; AS PER OUR SOPS; AND I NOTED THE TIME INDICATION ON MY CLOCK IN ORDER TO REF THE 2 MINS AS WELL. I MADE A MENTAL NOTE THAT MY CLOCK WAS OFF SLIGHTLY FROM CTR TIME AND NEEDED TO BE RESET; WHICH I WOULD DO LATER INFLT. I INITIATED A CLB; WHICH RESULTED IN A CLB RATE WELL IN ACCESS OF 3000 FPM. THEN OUT OF 34000 FT; I BEGAN REDUCING THE CLB RATE TO 1000 FPM; ALSO IN ACCORDANCE WITH OUR SOP. I INITIATED THE LEVELOFF PHASE AT 34700 FT; WHICH WAS THE LAST TIME I REFED THE FO'S CLOCK AND IT INDICATED 1 HR 50 MINS. AT ABOUT THE SAME TIME MY FO SPOTTED TFC AT OUR 10 O'CLOCK POS; 2000 FT BELOW US AND ABOUT 4-5 MI; AND WE HEARD A XMISSION WITH OUR CALL SIGN; SOMETHING GARBLED; AND THEN CUT OFF IN MID PHRASE. A FEW MINS LATER WE RECEIVED A FREQ CHANGE. WE NEVER RECEIVED ANY TFC INFO OR ANY INDICATION THAT THERE HAD BEEN A LOSS OF SEPARATION. I FEEL; IF THERE WOULD HAVE BEEN ANY POTENTIAL FOR SEPARATION LOSS; WE SHOULD HAVE RECEIVED A TFC ALERT; AN INQUIRY AS TO OUR CLB STATUS; OR AT LEAST AFTER THE FACT; SOME NOTIFICATION FROM THAT CTLR OR SUPVR; NOT 30 MINS LATER FROM ANOTHER CTR ALL TOGETHER. IN RETROSPECT; SINCE THIS CLRNC RESTR WAS SUCH A SHORT TIME SPAN; THERE WAS A POTENTIAL FOR CONFLICTING INFO. I DON'T FEEL IT IS LOGICAL TO GIVE SHORT TIME SPAN CLRNCS IN REF TO SPECIFIC TIMES. SINCE CLOCKS ARE SET DIFFERENTLY THIS LEADS TO CONFUSING TIME RESTRS AND POSSIBLE ASKING PLTS TO RESET CLOCKS DURING A CRITICAL PHASE OF FLT. SO WE REVERT TO THE MORE MANAGEABLE VALUE; 2 MINS; WHICH WILL BE THE SAME EVERYWHERE. THE ONLY PROB I SEE NOW IS WHEN DOES THE TIME START. OUR SOP STARTS THE TIME AFTER UNKEYING THE MIKE FROM ACCEPTING THE CLRNC; BUT WHAT DOES THE CTLR EXPECT? EITHER WAY; ON SHORT TIME RESTR CLRNC THIS CAN LEAD TO SEVERAL SECONDS OF CLB TIME AND SEVERAL HUNDRED FT IN ALT. IF WE HAD HAD MORE INFO; THAT THE CTLR FELT THERE WAS A POSSIBLE LOSS OF SEPARATION; IE; A TFC ALERT; TFC INFO ON INITIAL CLRNC; OR MAYBE A TCASII REQUIREMENT; THIS WOULD HAVE INCREASED OUR SITUATIONAL AWARENESS AND I COULD HAVE BRIEFED A DEV FROM OUR CLB SOP; REQUESTED A TURN; OR SOMETHING ELSE. AS IT TURNS OUT; I STILL FEEL WE MET THE REQUIREMENT OF THE CLRNC AND OUR SOP.
Source: NASA Aviation Safety Reporting System (public domain). Reports are voluntary submissions and are not verified by NASA.
Loading the flight search…
Pick an aircraft model — Boeing 737, Airbus A320, A380, Boeing 787 Dreamliner and more — enter your origin airport, and FlightFinder shows every route that plane flies from there with live fares.
We support Boeing 737/747/757/767/777/787, the full Airbus A220/A319/A320/A321/A330/A340/A350/A380 family, Embraer E170/E175/E190/E195, Bombardier CRJ and Dash 8, and the ATR 42/72 turboprops.
Search and schedules are free. Pro ($4.99/month, $39/year, or $99 one-time lifetime) unlocks the enriched flight card — on-time stats, CO₂ per passenger, amenities, live gate & weather — plus My Trips with push alerts.
Live schedules come from Amadeus, AeroDataBox and Travelpayouts. Observed routes (which aircraft actually flew a given city pair) are crowdsourced from adsb.lol ADS-B data under the Open Database License.