B747 first officer experiences a TCAS RA at FL370 on A590 north bound with a KC135 converging from t...

Attributes
ACN	1260108
Time
Date	201505
Local Time Of Day	0601-1200
Place
Locale Reference	RPHI.ARTCC
State Reference	FO
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Make Model Name	B747-400
Operating Under FAR Part	Part 121
Flight Phase	Cruise
Route In Use	Oceanic Airway A590
Flight Plan	IFR
Person 1
Function	Pilot Not Flying First Officer
Qualification	Flight Crew Air Transport Pilot (ATP) Flight Crew Flight Engineer
Experience	Flight Crew Last 90 Days 120 Flight Crew Total 25000 Flight Crew Type 10000
Events
Anomaly	Conflict Airborne Conflict Deviation - Altitude Excursion From Assigned Altitude
Miss Distance	Vertical 2200

Narrative:

Assigned FL370; northbound on airway A590 about 180 NM south of gurag intersection. The captain was pilot flying. We received a TCAS warning; 'traffic; traffic; descend; descend.' the traffic on TCAS was at our 0900 [o'clock] position (aircraft left) about 20 miles; at same altitude. I visually confirmed conflicting traffic in sight (captain did not see traffic). Captain did TCAS resolution maneuver; and descended. I monitored the descent on TCAS; and observed the conflicting traffic climbing; both on TCAS; and visually. We cleared traffic by 2;200 feet (per TCAS). We climbed back up to FL370; and when level; observed that conflicting traffic (now behind; and to our right) had also returned to FL370.we established contact with conflicting traffic on frequency 123.45. It was a KC135 tanker and he advised his cleared altitude was also FL370. Contacted manila radio on HF 8903 to pass along to manila control of our resolution advisory maneuver; and to also confirm our cleared altitude. Manila radio replied our confirmed altitude was FL370.

Original NASA ASRS Text

Title: B747 First Officer experiences a TCAS RA at FL370 on A590 north bound with a KC135 converging from the west at the same altitude. Evasive action is taken by both aircraft. Both aircraft were apparently at their correct altitude as assigned by Manila Control.

Narrative: Assigned FL370; northbound on Airway A590 about 180 NM south of GURAG Intersection. The Captain was pilot flying. We received a TCAS warning; 'TRAFFIC; TRAFFIC; DESCEND; DESCEND.' The traffic on TCAS was at our 0900 [o'clock] position (aircraft left) about 20 miles; at same altitude. I visually confirmed conflicting traffic in sight (Captain did not see traffic). Captain did TCAS resolution maneuver; and descended. I monitored the descent on TCAS; and observed the conflicting traffic climbing; both on TCAS; and visually. We cleared traffic by 2;200 feet (per TCAS). We climbed back up to FL370; and when level; observed that conflicting traffic (now behind; and to our right) had also returned to FL370.We established contact with conflicting traffic on frequency 123.45. It was a KC135 tanker and he advised his cleared altitude was also FL370. Contacted Manila Radio on HF 8903 to pass along to Manila Control of our resolution advisory maneuver; and to also confirm our cleared altitude. Manila Radio replied our confirmed altitude was FL370.

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.

B747 first officer experiences a TCAS RA at FL370 on A590 north bound with a KC135 converging from the west at the same altitude. Evasive action is taken by both aircraft. Both aircraft were apparently at their correct altitude as assigned by manila control.