CL604 flight crew reports TCAS TA at FL370 20 NM southeast of cea in vecf airspace with B747.

Attributes
ACN	771090
Time
Date	200801
Local Time Of Day	1201 To 1800
Place
Locale Reference	atc facility : vecf.artcc
State Reference	FO
Altitude	msl single value : 37000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : vecf.artcc
Operator	general aviation : corporate
Make Model Name	Challenger CL604
Operating Under FAR Part	Part 91
Navigation In Use	other
Flight Phase	cruise : level
Flight Plan	IFR
Aircraft 2
Controlling Facilities	artcc : vecf.artcc
Operator	common carrier : air carrier
Make Model Name	B747-400
Operating Under FAR Part	Part 129
Flight Phase	cruise : level
Flight Plan	IFR
Person 1
Affiliation	company : corporate
Function	flight crew : captain oversight : pic
Qualification	pilot : atp pilot : multi engine
Experience	flight time last 90 days : 90 flight time total : 17000 flight time type : 1300
ASRS Report	771090
Events
Anomaly	conflict : airborne less severe non adherence : required legal separation
Independent Detector	aircraft equipment : tcas other flight crewa
Resolutory Action	none taken : anomaly accepted
Miss Distance	horizontal : 22800 vertical : 0
Supplementary
Problem Areas	ATC Human Performance Flight Crew Human Performance
Primary Problem	ATC Human Performance

Narrative:

In cruise flight from vomm to vhhh initially level FL350. Chennai ATC requested our flight climb to FL370. Later while level FL370 new frequency and ATC handoff to kolkata ATC. Prior to passing legos intersection; kolkata cleared us direct sumag; report abeam legos. At XA57Z I made the position report abeam legos XA57 FL370. At XB02Z a TCAS target was observed at 11 O'clock position and 20 mi closing left to right. The target was observed visually as it moved into our 12 O'clock position at approximately 4 mi. A TA alert displayed and sounded as the traffic passed to the 1 O'clock position closing within 4 mi (possibly 3.5 mi). I advised ATC of the conflict and ATC responded with 'traffic under positive control.' I later contacted ATC and asked for the flight information for the conflict aircraft. ATC advised that the flight was aircraft Y; a B747. I called the flight on many frequencys and finally made contact with aircraft Y. I met the flight on frequency 123.45 where the pilot acknowledged we were observed on their TCAS. I advised aircraft Y that I would most probably be reporting the incident.

Original NASA ASRS Text

Title: CL604 FLT CREW REPORTS TCAS TA AT FL370 20 NM SE OF CEA IN VECF AIRSPACE WITH B747.

Narrative: IN CRUISE FLT FROM VOMM TO VHHH INITIALLY LEVEL FL350. CHENNAI ATC REQUESTED OUR FLT CLB TO FL370. LATER WHILE LEVEL FL370 NEW FREQ AND ATC HDOF TO KOLKATA ATC. PRIOR TO PASSING LEGOS INTXN; KOLKATA CLRED US DIRECT SUMAG; RPT ABEAM LEGOS. AT XA57Z I MADE THE POS RPT ABEAM LEGOS XA57 FL370. AT XB02Z A TCAS TARGET WAS OBSERVED AT 11 O'CLOCK POS AND 20 MI CLOSING L TO R. THE TARGET WAS OBSERVED VISUALLY AS IT MOVED INTO OUR 12 O'CLOCK POS AT APPROX 4 MI. A TA ALERT DISPLAYED AND SOUNDED AS THE TFC PASSED TO THE 1 O'CLOCK POS CLOSING WITHIN 4 MI (POSSIBLY 3.5 MI). I ADVISED ATC OF THE CONFLICT AND ATC RESPONDED WITH 'TFC UNDER POSITIVE CTL.' I LATER CONTACTED ATC AND ASKED FOR THE FLT INFO FOR THE CONFLICT ACFT. ATC ADVISED THAT THE FLT WAS ACFT Y; A B747. I CALLED THE FLT ON MANY FREQS AND FINALLY MADE CONTACT WITH ACFT Y. I MET THE FLT ON FREQ 123.45 WHERE THE PLT ACKNOWLEDGED WE WERE OBSERVED ON THEIR TCAS. I ADVISED ACFT Y THAT I WOULD MOST PROBABLY BE REPORTING THE INCIDENT.

Data retrieved from NASA's ASRS site as of May 2009 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.