Narrative:

Approach control cleared us to intercept and fly the localizer back course runway 28 from a 310 degree heading inside nikoo, but at 3000 ft, because of a traffic conflict. The approach called it to be at 1400 ft at 4.6 DME. Almost immediately after clearing us for the approach we intercepted the localizer and were instructed to contact dorval tower. Realizing we were 800 ft high at the 4.6 idu DME and since we heard no other traffic but an air carrier flight touching down ahead of us, we asked tower if we could make a 360 degree turn on final, thinking to cross 4.6 at 1400 ft. Tower responded 'left or right?' we replied 'left would be fine,' to which tower replied 'ok, left 360 degrees.' we commenced a gradually descending left 360 degree turn. Tower then had us go back to approach control. Approach instructed us to climb immediately to 3000 ft and gave us a 180 degree heading. He seemed very agitated, but vectored us out for another localizer back course approach. After landing I telephoned tower to ask why approach had acted so upset. The tower cabin attendant supervisor stated that the tower controller did not have the authority/authorized to deviate from anything but standard missed approach procedure, but had merely ok'd our left 360 degree turn to get our intentions approved by the approach controller. An acknowledged ok to our 360 degree turn request was not a clearance.

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Original NASA ASRS Text

Title: NON ADHERENCE TO ATC CLRNC INSTRUCTION PROC. 360 DEG TURN MADE DURING CLRNC INTERP PROB.

Narrative: APCH CTL CLRED US TO INTERCEPT AND FLY THE LOC BC RWY 28 FROM A 310 DEG HDG INSIDE NIKOO, BUT AT 3000 FT, BECAUSE OF A TFC CONFLICT. THE APCH CALLED IT TO BE AT 1400 FT AT 4.6 DME. ALMOST IMMEDIATELY AFTER CLRING US FOR THE APCH WE INTERCEPTED THE LOC AND WERE INSTRUCTED TO CONTACT DORVAL TWR. REALIZING WE WERE 800 FT HIGH AT THE 4.6 IDU DME AND SINCE WE HEARD NO OTHER TFC BUT AN ACR FLT TOUCHING DOWN AHEAD OF US, WE ASKED TWR IF WE COULD MAKE A 360 DEG TURN ON FINAL, THINKING TO CROSS 4.6 AT 1400 FT. TWR RESPONDED 'L OR R?' WE REPLIED 'L WOULD BE FINE,' TO WHICH TWR REPLIED 'OK, L 360 DEGS.' WE COMMENCED A GRADUALLY DSNDING L 360 DEG TURN. TWR THEN HAD US GO BACK TO APCH CTL. APCH INSTRUCTED US TO CLB IMMEDIATELY TO 3000 FT AND GAVE US A 180 DEG HDG. HE SEEMED VERY AGITATED, BUT VECTORED US OUT FOR ANOTHER LOC BC APCH. AFTER LNDG I TELEPHONED TWR TO ASK WHY APCH HAD ACTED SO UPSET. THE TWR CAB SUPVR STATED THAT THE TWR CTLR DID NOT HAVE THE AUTH TO DEVIATE FROM ANYTHING BUT STANDARD MISSED APCH PROC, BUT HAD MERELY OK'D OUR L 360 DEG TURN TO GET OUR INTENTIONS APPROVED BY THE APCH CTLR. AN ACKNOWLEDGED OK TO OUR 360 DEG TURN REQUEST WAS NOT A CLRNC.

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.