Narrative:

We were flight X from ZZZZ to subic bay, pl. We had previously planned and briefed to fly the GPS RNAV 07 approach into subic bay. Both crew members are qualified to fly this approach. We were at FL150 with subic approach control when we received a clearance to 7000 ft. We read back and confirmed this altitude. We were also on a direct clearance to redon, the IAF for this approach. Prior to this, subic had cleared us direct to sba, but we challenged this and then received the direct clearance to redon, which was our flight plan clearance limit and desired point to begin an approach. The descent profile had us well above the profile descent, so spoilers were selected for the descent. As we were passing 7500 ft, we received a clearance to 5000 ft. Because the approach controller was now working several aircraft, and we had visual and TCASII identify of 2 aircraft in our 10 O'clock position, we attempted to clarify the clearance to 5000 ft, as he was difficult to understand and was making continuous xmissions to the other aircraft. Additionally, we were concerned about this clearance because the IAF altitude is 5500 ft. Then the controller began to challenge us to level off at 9000 ft because he claimed that was the clearance he had given us prior. There was insufficient time to clarify this because we now believed we had to establish our own separation from one of the other aircraft. During all of this, we were concerned about the proximity to other aircraft because the TCASII showed us at the same altitude. The controller was busy talking with the conflicting aircraft. We then received a traffic alert with this aircraft. We elected to continue the descent to 5000 ft to provide separation both visually and via the TCASII. We initiated a communication to the other aircraft that we had visual and TCASII with him and were continuing the descent to insure separation. At 5000 ft, we entered the holding pattern at redon and the controller again challenged us to why we were at 5000 ft when we were supposed to be at 9000 ft (according to him). In the holding pattern, he finally told us to maintain 5000 ft and cleared us for the approach. We requested and received clearance to 5500 ft and then flew an uneventful approach and landing to subic bay. On the ground, the captain contacted the tower and discussed the situation and they indicated they would pull the tapes and inform us of what actually transpired. We also contacted the subic assistant chief pilot to bring him up to speed on the incident. Problems: 1) controller's radio had a lot of static. 2) at least 3 company aircraft arriving at the same time for landing at subic. 3) some aircraft had requested the RNAV approach and one had requested the VOR approach. 4) the controller was talking nearly continuously to all of the aircraft and thus it was impossible to clarify clrncs. 5) there was no effort to resolve a potential traffic conflict nor did the controller attempt to identify other aircraft in our immediate area. Suggestions: 1) prioritize the arrival approach procedure(south) with the GPS approach as the preferred arrival. Company flight standards should re-emphasize this to all flight crews regardless of aircraft type. This emphasis should flow to the approach controllers with them assigning the GPS approach as the default arrival. It would then be a crew option to select another arrival if so desired. 2) ATC radio equipment should be checked for quality and consistency of transmission on a more frequent and routine basis. Static definitely was a factor in this incident. 3A) the controllers should be briefed on the importance of brevity and conciseness of their xmissions. 3B) it should be re-emphasized to the controllers that their task management of sits (especially traffic conflicts) needs to be more aggressive and resolution oriented.

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Original NASA ASRS Text

Title: AN MD11 FLT CREW HAS TO PROMPT RPLB APCH CTLR FOR CORRECT CLRNCS AND EXPERIENCES A POTENTIAL CONFLICT OVER A SKEWED CLRNC FROM ATC NEAR REDON INTXN, FO.

Narrative: WE WERE FLT X FROM ZZZZ TO SUBIC BAY, PL. WE HAD PREVIOUSLY PLANNED AND BRIEFED TO FLY THE GPS RNAV 07 APCH INTO SUBIC BAY. BOTH CREW MEMBERS ARE QUALIFIED TO FLY THIS APCH. WE WERE AT FL150 WITH SUBIC APCH CTL WHEN WE RECEIVED A CLRNC TO 7000 FT. WE READ BACK AND CONFIRMED THIS ALT. WE WERE ALSO ON A DIRECT CLRNC TO REDON, THE IAF FOR THIS APCH. PRIOR TO THIS, SUBIC HAD CLRED US DIRECT TO SBA, BUT WE CHALLENGED THIS AND THEN RECEIVED THE DIRECT CLRNC TO REDON, WHICH WAS OUR FLT PLAN CLRNC LIMIT AND DESIRED POINT TO BEGIN AN APCH. THE DSCNT PROFILE HAD US WELL ABOVE THE PROFILE DSCNT, SO SPOILERS WERE SELECTED FOR THE DSCNT. AS WE WERE PASSING 7500 FT, WE RECEIVED A CLRNC TO 5000 FT. BECAUSE THE APCH CTLR WAS NOW WORKING SEVERAL ACFT, AND WE HAD VISUAL AND TCASII IDENT OF 2 ACFT IN OUR 10 O'CLOCK POS, WE ATTEMPTED TO CLARIFY THE CLRNC TO 5000 FT, AS HE WAS DIFFICULT TO UNDERSTAND AND WAS MAKING CONTINUOUS XMISSIONS TO THE OTHER ACFT. ADDITIONALLY, WE WERE CONCERNED ABOUT THIS CLRNC BECAUSE THE IAF ALT IS 5500 FT. THEN THE CTLR BEGAN TO CHALLENGE US TO LEVEL OFF AT 9000 FT BECAUSE HE CLAIMED THAT WAS THE CLRNC HE HAD GIVEN US PRIOR. THERE WAS INSUFFICIENT TIME TO CLARIFY THIS BECAUSE WE NOW BELIEVED WE HAD TO ESTABLISH OUR OWN SEPARATION FROM ONE OF THE OTHER ACFT. DURING ALL OF THIS, WE WERE CONCERNED ABOUT THE PROX TO OTHER ACFT BECAUSE THE TCASII SHOWED US AT THE SAME ALT. THE CTLR WAS BUSY TALKING WITH THE CONFLICTING ACFT. WE THEN RECEIVED A TFC ALERT WITH THIS ACFT. WE ELECTED TO CONTINUE THE DSCNT TO 5000 FT TO PROVIDE SEPARATION BOTH VISUALLY AND VIA THE TCASII. WE INITIATED A COM TO THE OTHER ACFT THAT WE HAD VISUAL AND TCASII WITH HIM AND WERE CONTINUING THE DSCNT TO INSURE SEPARATION. AT 5000 FT, WE ENTERED THE HOLDING PATTERN AT REDON AND THE CTLR AGAIN CHALLENGED US TO WHY WE WERE AT 5000 FT WHEN WE WERE SUPPOSED TO BE AT 9000 FT (ACCORDING TO HIM). IN THE HOLDING PATTERN, HE FINALLY TOLD US TO MAINTAIN 5000 FT AND CLRED US FOR THE APCH. WE REQUESTED AND RECEIVED CLRNC TO 5500 FT AND THEN FLEW AN UNEVENTFUL APCH AND LNDG TO SUBIC BAY. ON THE GND, THE CAPT CONTACTED THE TWR AND DISCUSSED THE SIT AND THEY INDICATED THEY WOULD PULL THE TAPES AND INFORM US OF WHAT ACTUALLY TRANSPIRED. WE ALSO CONTACTED THE SUBIC ASSISTANT CHIEF PLT TO BRING HIM UP TO SPD ON THE INCIDENT. PROBS: 1) CTLR'S RADIO HAD A LOT OF STATIC. 2) AT LEAST 3 COMPANY ACFT ARRIVING AT THE SAME TIME FOR LNDG AT SUBIC. 3) SOME ACFT HAD REQUESTED THE RNAV APCH AND ONE HAD REQUESTED THE VOR APCH. 4) THE CTLR WAS TALKING NEARLY CONTINUOUSLY TO ALL OF THE ACFT AND THUS IT WAS IMPOSSIBLE TO CLARIFY CLRNCS. 5) THERE WAS NO EFFORT TO RESOLVE A POTENTIAL TFC CONFLICT NOR DID THE CTLR ATTEMPT TO IDENTIFY OTHER ACFT IN OUR IMMEDIATE AREA. SUGGESTIONS: 1) PRIORITIZE THE ARR APCH PROC(S) WITH THE GPS APCH AS THE PREFERRED ARR. COMPANY FLT STANDARDS SHOULD RE-EMPHASIZE THIS TO ALL FLT CREWS REGARDLESS OF ACFT TYPE. THIS EMPHASIS SHOULD FLOW TO THE APCH CTLRS WITH THEM ASSIGNING THE GPS APCH AS THE DEFAULT ARR. IT WOULD THEN BE A CREW OPTION TO SELECT ANOTHER ARR IF SO DESIRED. 2) ATC RADIO EQUIP SHOULD BE CHKED FOR QUALITY AND CONSISTENCY OF XMISSION ON A MORE FREQUENT AND ROUTINE BASIS. STATIC DEFINITELY WAS A FACTOR IN THIS INCIDENT. 3A) THE CTLRS SHOULD BE BRIEFED ON THE IMPORTANCE OF BREVITY AND CONCISENESS OF THEIR XMISSIONS. 3B) IT SHOULD BE RE-EMPHASIZED TO THE CTLRS THAT THEIR TASK MGMNT OF SITS (ESPECIALLY TFC CONFLICTS) NEEDS TO BE MORE AGGRESSIVE AND RESOLUTION ORIENTED.

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.