TCASII alert and RA avoids conflict.

Attributes
ACN	296396
Time
Date	199502
Day	Sun
Local Time Of Day	1201 To 1800
Place
Locale Reference	atc facility : hmo
State Reference	FO
Altitude	msl bound lower : 28000 msl bound upper : 28000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : mmzt
Operator	common carrier : air carrier
Make Model Name	B737-200
Operating Under FAR Part	Part 121
Flight Phase	climbout : intermediate altitude cruise other
Route In Use	enroute airway : mmzt
Flight Plan	IFR
Aircraft 2
Operator	common carrier : air carrier
Make Model Name	B727 Undifferentiated or Other Model
Operating Under FAR Part	Part 121
Flight Phase	cruise other cruise other
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Experience	flight time last 90 days : 220 flight time total : 17000 flight time type : 7000
ASRS Report	296396
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : commercial pilot : instrument
Events
Anomaly	altitude deviation : excursion from assigned altitude conflict : airborne less severe other anomaly other
Independent Detector	aircraft equipment other aircraft equipment : unspecified other flight crewa
Resolutory Action	flight crew : took evasive action
Consequence	Other
Miss Distance	horizontal : 20 vertical : 800
Supplementary
Primary Problem	ATC Human Performance
Air Traffic Incident	Operational Error other

Narrative:

Flight XXXX was in cruise flight at assigned FL280 and in communication with mazatlan center. At approximately XX30 and 10 NM north of hmo VORTAC, we received a TCASII traffic alert at 6 NM north of our position and 600 ft below us. As the target moved toward us from the 12 O'clock position, altitude separation became 500 ft then 400 ft and still closing dead ahead! We initiated a climb just prior to TCASII resolution of 'monitor vertical speed' followed quickly with 'climb, climb now!' we climbed to FL290, received TCASII 'clear of conflict,' and descended back to FL280. During this scenario, my first officer declared to mmzt ARTCC that we were deviating for a TCASII conflict, no response from mmzt ARTCC! He told them we were at FL290, no response! When we descended back to FL280, he 'again' informed mmzt ARTCC that we were back to assigned FL280, and again, no response! During this entire scenario, mmzt ARTCC never replied once to our incident! The intruder, a B727 passing below us slightly right of centerline! Air crews, be alert and believe your TCASII.

Original NASA ASRS Text

Title: TCASII ALERT AND RA AVOIDS CONFLICT.

Narrative: FLT XXXX WAS IN CRUISE FLT AT ASSIGNED FL280 AND IN COM WITH MAZATLAN CTR. AT APPROX XX30 AND 10 NM N OF HMO VORTAC, WE RECEIVED A TCASII TFC ALERT AT 6 NM N OF OUR POS AND 600 FT BELOW US. AS THE TARGET MOVED TOWARD US FROM THE 12 O'CLOCK POS, ALT SEPARATION BECAME 500 FT THEN 400 FT AND STILL CLOSING DEAD AHEAD! WE INITIATED A CLB JUST PRIOR TO TCASII RESOLUTION OF 'MONITOR VERT SPD' FOLLOWED QUICKLY WITH 'CLB, CLB NOW!' WE CLBED TO FL290, RECEIVED TCASII 'CLR OF CONFLICT,' AND DSNDED BACK TO FL280. DURING THIS SCENARIO, MY FO DECLARED TO MMZT ARTCC THAT WE WERE DEVIATING FOR A TCASII CONFLICT, NO RESPONSE FROM MMZT ARTCC! HE TOLD THEM WE WERE AT FL290, NO RESPONSE! WHEN WE DSNDED BACK TO FL280, HE 'AGAIN' INFORMED MMZT ARTCC THAT WE WERE BACK TO ASSIGNED FL280, AND AGAIN, NO RESPONSE! DURING THIS ENTIRE SCENARIO, MMZT ARTCC NEVER REPLIED ONCE TO OUR INCIDENT! THE INTRUDER, A B727 PASSING BELOW US SLIGHTLY R OF CTRLINE! AIR CREWS, BE ALERT AND BELIEVE YOUR TCASII.

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.