Piarco control granted the crew's climb request from FL340 to FL360. Another aircraft with a similar...

Attributes
ACN	1167481
Time
Date	201404
Local Time Of Day	0001-0600
Place
Locale Reference	TTZP.ARTCC
State Reference	FO
Environment
Flight Conditions	VMC
Light	Night
Aircraft 1
Make Model Name	Commercial Fixed Wing
Operating Under FAR Part	Part 121
Flight Phase	Cruise
Person 1
Function	Pilot Flying First Officer
Experience	Flight Crew Total 9
Person 2
Function	First Officer Pilot Not Flying
Qualification	Flight Crew Air Transport Pilot (ATP)
Events
Anomaly	ATC Issue All Types Conflict Airborne Conflict Deviation - Procedural Published Material / Policy Deviation - Procedural Clearance

Narrative:

Over waypoint perga we requested climb from FL340 to FL360. Piarco control cleared us direct anada and to climb to FL360. Clearance was read back slowly and clearly and piarco said nothing. As aircraft climbed through FL350; another aircraft with a similar sounding call sign at FL360 several miles behind us called piarco and noted our converging altitudes. We began an immediate descent back to FL340 without further incident. Piarco claimed he had not cleared us to climb; but we emphatically stated otherwise. Poor radio reception; poor controller english; and similar sounding callsigns were contributing factors. Closer attention to call signs and clearly understood clearance (by controller after readback by aircraft) must be maintained.

Original NASA ASRS Text

Title: Piarco Control granted the crew's climb request from FL340 to FL360. Another aircraft with a similar sounding call sign behind the climbing aircraft called Piarco to remind ATC their aircraft were converging at FL360 so the climbing crew descended to FL340.

Narrative: Over waypoint PERGA we requested climb from FL340 to FL360. PIARCO Control cleared us direct ANADA and to climb to FL360. Clearance was read back slowly and clearly and PIARCO said nothing. As aircraft climbed through FL350; another aircraft with a similar sounding call sign at FL360 several miles behind us called PIARCO and noted our converging altitudes. We began an immediate descent back to FL340 without further incident. PIARCO claimed he had not cleared us to climb; but we emphatically stated otherwise. Poor radio reception; poor controller English; and similar sounding callsigns were contributing factors. Closer attention to call signs and clearly understood clearance (by controller after readback by aircraft) must be maintained.

Data retrieved from NASA's ASRS site 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.

Piarco control granted the crew's climb request from FL340 to FL360. Another aircraft with a similar sounding call sign behind the climbing aircraft called piarco to remind ATC their aircraft were converging at FL360 so the climbing crew descended to FL340.