ZID controller described a separation event during a busy traffic period which included aircraft wit...

Narrative:

Air carrier X northeast bound FL370 turned 5 degrees left to go behind air carrier west 1221 and air carrier Y. Air carrier west 1221 turned 5 degrees right to stay in front of air carrier Y. Air carrier Y assigned present heading to go between the two. Air carrier Z 1221 blocked the transmission to air carrier Y asking if the turn for air carrier west 1221 was for him. After correcting the confusion I had another flight at FL350 declare he needed a different altitude. There had been chop in the area so I assumed he wanted to change altitude for the ride; he wasn't very clear as to the need for change nor was the transmission legible. He stated again he wanted lower and this time said smoke in the cockpit. My attention was diverted from the air carrier Y missed readback as I assisted the aircraft with the smoke issue with alternate airports and getting him down to 10000 ft. Conflict alert activated and TCAS was invoked by air carrier X. Air carrier Y said he never was assigned present heading when questioned. Also there was a military refueling flight requesting to break up at the same time. Recommendation; better radios and I was told; that the similar call signs air carrier Z 1221 and air carrier west 1221 had been turned in numerous times.

Original NASA ASRS Text

Title: ZID Controller described a separation event during a busy traffic period which included aircraft with similar flight numbers; a military flight requesting a break up and an aircraft reporting smoke in the cockpit; all leading to a missed clearance instruction.

Narrative: Air Carrier X northeast bound FL370 turned 5 degrees left to go behind Air Carrier W 1221 and Air Carrier Y. Air Carrier W 1221 turned 5 degrees right to stay in front of Air Carrier Y. Air Carrier Y assigned present heading to go between the two. Air Carrier Z 1221 blocked the transmission to Air Carrier Y asking if the turn for Air Carrier W 1221 was for him. After correcting the confusion I had another flight at FL350 declare he needed a different altitude. There had been chop in the area so I assumed he wanted to change altitude for the ride; he wasn't very clear as to the need for change nor was the transmission legible. He stated again he wanted lower and this time said smoke in the cockpit. My attention was diverted from the Air Carrier Y missed readback as I assisted the aircraft with the smoke issue with alternate airports and getting him down to 10000 FT. Conflict alert activated and TCAS was invoked by Air Carrier X. Air Carrier Y said he never was assigned present heading when questioned. Also there was a military refueling flight requesting to break up at the same time. Recommendation; better radios and I was told; that the similar call signs Air Carrier Z 1221 and Air Carrier W 1221 had been turned in numerous times.

Data retrieved from NASA's ASRS site as of April 2012 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.

Attributes
ACN	894100
Time
Date	201006
Local Time Of Day	0001-0600
Place
Locale Reference	ZID.ARTCC
State Reference	IN
Aircraft 1
Make Model Name	Commercial Fixed Wing
Operating Under FAR Part	Part 121
Flight Phase	Cruise
Route In Use	Vectors
Flight Plan	IFR
Aircraft 2
Make Model Name	Commercial Fixed Wing
Operating Under FAR Part	Part 121
Flight Phase	Cruise
Route In Use	Vectors
Flight Plan	IFR
Person 1
Qualification	Air Traffic Control Fully Certified
Events
Anomaly	ATC Issue All Types Deviation - Procedural Published Material / Policy

ZID controller described a separation event during a busy traffic period which included aircraft with similar flight numbers; a military flight requesting a break up and an aircraft reporting smoke in the cockpit; all leading to a missed clearance instruction.