Similar call signs led to less than desired separation in ZMA airspace.

Attributes
ACN	470275
Time
Date	200004
Day	Sun
Local Time Of Day	0601 To 1200
Place
State Reference	FL
Altitude	msl bound lower : 27000 msl bound upper : 29000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zma.artcc tower : iah.tower
Operator	general aviation : corporate
Make Model Name	Citation II S2/Bravo
Operating Under FAR Part	Part 91
Navigation In Use	other
Flight Plan	IFR
Aircraft 2
Controlling Facilities	artcc : zma.artcc
Make Model Name	Any Unknown or Unlisted Aircraft Manufacturer
Operating Under FAR Part	Part 91
Flight Phase	cruise : level
Flight Plan	IFR
Person 1
Function	flight crew : first officer
Qualification	pilot : atp
Experience	flight time last 90 days : 120 flight time total : 3600 flight time type : 150
ASRS Report	470275
Person 2
Function	flight crew : captain oversight : pic
Qualification	pilot : multi engine pilot : cfi pilot : atp
Experience	flight time last 90 days : 120 flight time total : 3780 flight time type : 230
ASRS Report	470133
Events
Independent Detector	other controllera other flight crewa other flight crewb
Resolutory Action	none taken : detected after the fact
Consequence	faa : reviewed incident with flight crew
Supplementary
Problem Areas	ATC Human Performance
Primary Problem	ATC Human Performance
Air Traffic Incident	Operational Error

Narrative:

En route ktmb to mdlr, cleared direct albee intersection, FL270. Miami advised traffic at 12 O'clock and 20 mi descending to FL280. After a few mins, ATC cleared us to FL290. 2 sectors later requested (at FL370) us to call ZMA upon landing at mdlr. In our opinion, the other aircraft (previously mentioned 'traffic') was of a similar call sign and the controller wanted them to maintain FL290 instead of FL280, and mistakenly used our call sign. We read back our call sign and clearance to FL290 and were not corrected and no further communication was made to the effect of our altitude readback.

Original NASA ASRS Text

Title: SIMILAR CALL SIGNS LED TO LESS THAN DESIRED SEPARATION IN ZMA AIRSPACE.

Narrative: ENRTE KTMB TO MDLR, CLRED DIRECT ALBEE INTXN, FL270. MIAMI ADVISED TFC AT 12 O'CLOCK AND 20 MI DSNDING TO FL280. AFTER A FEW MINS, ATC CLRED US TO FL290. 2 SECTORS LATER REQUESTED (AT FL370) US TO CALL ZMA UPON LNDG AT MDLR. IN OUR OPINION, THE OTHER ACFT (PREVIOUSLY MENTIONED 'TFC') WAS OF A SIMILAR CALL SIGN AND THE CTLR WANTED THEM TO MAINTAIN FL290 INSTEAD OF FL280, AND MISTAKENLY USED OUR CALL SIGN. WE READ BACK OUR CALL SIGN AND CLRNC TO FL290 AND WERE NOT CORRECTED AND NO FURTHER COM WAS MADE TO THE EFFECT OF OUR ALT READBACK.

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.