Reported loss of separation from apparent confusion when air carrier X, with clearance to FL390, mis...

Attributes
ACN	398463
Time
Date	199707
Day	Sat
Local Time Of Day	0601 To 1200
Place
Locale Reference	atc facility : uam
State Reference	FO
Altitude	msl bound lower : 37000 msl bound upper : 37000
Environment
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : rjtg artcc : zoa
Operator	common carrier : air carrier
Make Model Name	Commercial Fixed Wing
Operating Under FAR Part	Part 121
Flight Phase	climbout : intermediate altitude cruise other descent other
Route In Use	enroute : pacific enroute : other oceanic
Flight Plan	IFR
Aircraft 2
Operator	common carrier : air carrier
Make Model Name	Commercial Fixed Wing
Operating Under FAR Part	Part 121
Flight Phase	cruise other
Route In Use	enroute : pacific
Flight Plan	IFR
Person 1
Affiliation	Other
Function	other personnel other
Qualification	other other : other
ASRS Report	398463
Person 2
Affiliation	Other
Function	other personnel other
Qualification	other other : other
Events
Anomaly	conflict : airborne less severe non adherence : clearance non adherence : required legal separation other anomaly other other anomaly other
Independent Detector	other controllera
Resolutory Action	none taken : detected after the fact
Consequence	faa : investigated
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

Air carrier X was en route from new zealand to korea along ats route G339. This route takes the aircraft through airspace controled by the guam cerap. During the xfer coordination with the guam controller, the ZOA controller requested that a clearance be issued to air carrier X to cross 20 degrees north latitude at FL390. Air carrier X was at FL370. This was accomplished as requested. Air carrier X attempted to contact honolulu radio to report leaving FL370 as required by ICAO rules. At this same time, the honolulu radio operator was attempting to issue a clearance to another aircraft, air carrier Y, to climb to FL370. When the operator heard air carrier X on frequency, the erroneous assumption was made that this aircraft was taking the clearance intended for air carrier Y. In fact, each transmission from air carrier X indicated that the aircraft was leaving FL370 to cross 20 degrees north at FL390. The radio operator assigned air carrier X a new frequency to monitor, and then issued the clearance for air carrier Y again. When air carrier X again attempted to report leaving, the radio operator stated 'negative, that clearance is for air carrier Y.' air carrier X reported level at FL370, with an estimate for waypoint pakdo. The aircraft had initiated a climb to FL390 as previously cleared, but returned to FL370 based on information received from the honolulu radio operator. The ZOA controller contacted tokyo acc and advised them that air carrier X was at FL370 and that attempts to issue a new clearance to FL390 had been unsuccessful. Tokyo acc had traffic, air carrier Z, at FL370, and separation was lost between that aircraft and air carrier X. Honolulu radio was eventually able to establish communications with air carrier X, and the aircraft was cleared to FL390. This was an FAA operational error. Foreign language comprehension was a factor in this error as well as the radio operator not being aware of a clearance having been delivered through another agency (guam cerap).

Original NASA ASRS Text

Title: RPTED LOSS OF SEPARATION FROM APPARENT CONFUSION WHEN ACR X, WITH CLRNC TO FL390, MISINTERPS INSTRUCTIONS FROM THE RADIO OPERATOR AND DSNDS BACK TO FL370 AND CONFLICTS WITH ACR Z AT FL370. THE RADIO OPERATOR WAS ATTEMPTING TO CLB ACR Y, A COMPANY ACFT, TO ACR X WITH A SIMILAR CALL SIGN.

Narrative: ACR X WAS ENRTE FROM NEW ZEALAND TO KOREA ALONG ATS RTE G339. THIS RTE TAKES THE ACFT THROUGH AIRSPACE CTLED BY THE GUAM CERAP. DURING THE XFER COORD WITH THE GUAM CTLR, THE ZOA CTLR REQUESTED THAT A CLRNC BE ISSUED TO ACR X TO CROSS 20 DEGS N LATITUDE AT FL390. ACR X WAS AT FL370. THIS WAS ACCOMPLISHED AS REQUESTED. ACR X ATTEMPTED TO CONTACT HONOLULU RADIO TO RPT LEAVING FL370 AS REQUIRED BY ICAO RULES. AT THIS SAME TIME, THE HONOLULU RADIO OPERATOR WAS ATTEMPTING TO ISSUE A CLRNC TO ANOTHER ACFT, ACR Y, TO CLB TO FL370. WHEN THE OPERATOR HEARD ACR X ON FREQ, THE ERRONEOUS ASSUMPTION WAS MADE THAT THIS ACFT WAS TAKING THE CLRNC INTENDED FOR ACR Y. IN FACT, EACH XMISSION FROM ACR X INDICATED THAT THE ACFT WAS LEAVING FL370 TO CROSS 20 DEGS N AT FL390. THE RADIO OPERATOR ASSIGNED ACR X A NEW FREQ TO MONITOR, AND THEN ISSUED THE CLRNC FOR ACR Y AGAIN. WHEN ACR X AGAIN ATTEMPTED TO RPT LEAVING, THE RADIO OPERATOR STATED 'NEGATIVE, THAT CLRNC IS FOR ACR Y.' ACR X RPTED LEVEL AT FL370, WITH AN ESTIMATE FOR WAYPOINT PAKDO. THE ACFT HAD INITIATED A CLB TO FL390 AS PREVIOUSLY CLRED, BUT RETURNED TO FL370 BASED ON INFO RECEIVED FROM THE HONOLULU RADIO OPERATOR. THE ZOA CTLR CONTACTED TOKYO ACC AND ADVISED THEM THAT ACR X WAS AT FL370 AND THAT ATTEMPTS TO ISSUE A NEW CLRNC TO FL390 HAD BEEN UNSUCCESSFUL. TOKYO ACC HAD TFC, ACR Z, AT FL370, AND SEPARATION WAS LOST BTWN THAT ACFT AND ACR X. HONOLULU RADIO WAS EVENTUALLY ABLE TO ESTABLISH COMS WITH ACR X, AND THE ACFT WAS CLRED TO FL390. THIS WAS AN FAA OPERROR. FOREIGN LANGUAGE COMPREHENSION WAS A FACTOR IN THIS ERROR AS WELL AS THE RADIO OPERATOR NOT BEING AWARE OF A CLRNC HAVING BEEN DELIVERED THROUGH ANOTHER AGENCY (GUAM CERAP).

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.