Medium large transport encounters blocked frequency on handoff. TCASII RA sounds.

Attributes
ACN	274201
Time
Date	199406
Day	Fri
Local Time Of Day	0601 To 1200
Place
Locale Reference	atc facility : stl
State Reference	MO
Altitude	msl bound lower : 31000 msl bound upper : 32000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zkc tracon : bwi
Operator	common carrier : air carrier
Make Model Name	Commercial Fixed Wing
Operating Under FAR Part	Part 121
Navigation In Use	Other Other
Flight Phase	cruise other
Flight Plan	IFR
Aircraft 2
Make Model Name	Commercial Fixed Wing
Operating Under FAR Part	other : unknown
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : flight engineer pilot : atp
Experience	flight time last 90 days : 160 flight time total : 10000 flight time type : 1000
ASRS Report	274201
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : instrument pilot : commercial
Events
Anomaly	altitude deviation : excursion from assigned altitude conflict : airborne less severe non adherence : clearance other anomaly other
Independent Detector	aircraft equipment other aircraft equipment : unspecified other flight crewa
Resolutory Action	flight crew : took evasive action flight crew : overcame equipment problem
Consequence	Other
Miss Distance	horizontal : 0 vertical : 900
Supplementary
Air Traffic Incident	other

Narrative:

While in cruise at FL310, just north of stl we were given by ATC a substantial rerte to destination dfw. We were then switched to ZKC frequency 127.22 MHZ. Checking in on the new frequency was being made impossible by what appeared to be a stuck microphone transmitter on another aircraft. While in the process of returning to the previous frequency we received a TCASII TA, quickly followed by an RA to climb. We immediately initiated a climb, and followed TCASII instruction. At FL320 we saw a 'right to left' aircraft immediately above us, and then looking out my left window, saw a 'left to right' aircraft immediately below us. The aircraft below us had a vertical separation of approximately 900 ft and a lateral separation of '0' ft. We received a new ATC frequency and returned to our originally assigned altitude. Had it not been for the TCASII system and the training that goes with it, then this could have been a major tragedy over the city of st. Louis.

Original NASA ASRS Text

Title: MLG ENCOUNTERS BLOCKED FREQ ON HDOF. TCASII RA SOUNDS.

Narrative: WHILE IN CRUISE AT FL310, JUST N OF STL WE WERE GIVEN BY ATC A SUBSTANTIAL RERTE TO DEST DFW. WE WERE THEN SWITCHED TO ZKC FREQ 127.22 MHZ. CHKING IN ON THE NEW FREQ WAS BEING MADE IMPOSSIBLE BY WHAT APPEARED TO BE A STUCK MIKE XMITTER ON ANOTHER ACFT. WHILE IN THE PROCESS OF RETURNING TO THE PREVIOUS FREQ WE RECEIVED A TCASII TA, QUICKLY FOLLOWED BY AN RA TO CLB. WE IMMEDIATELY INITIATED A CLB, AND FOLLOWED TCASII INSTRUCTION. AT FL320 WE SAW A 'R TO L' ACFT IMMEDIATELY ABOVE US, AND THEN LOOKING OUT MY L WINDOW, SAW A 'L TO R' ACFT IMMEDIATELY BELOW US. THE ACFT BELOW US HAD A VERT SEPARATION OF APPROX 900 FT AND A LATERAL SEPARATION OF '0' FT. WE RECEIVED A NEW ATC FREQ AND RETURNED TO OUR ORIGINALLY ASSIGNED ALT. HAD IT NOT BEEN FOR THE TCASII SYS AND THE TRAINING THAT GOES WITH IT, THEN THIS COULD HAVE BEEN A MAJOR TRAGEDY OVER THE CITY OF ST. LOUIS.

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.