Large transport given clearance to descend as TCASII RA sounds.

Attributes
ACN	274412
Time
Date	199406
Day	Wed
Local Time Of Day	0601 To 1200
Place
Locale Reference	atc facility : tul
State Reference	OK
Altitude	msl bound lower : 28000 msl bound upper : 35000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zfw
Operator	common carrier : air carrier
Make Model Name	Commercial Fixed Wing
Operating Under FAR Part	Part 121
Flight Phase	cruise other descent other
Route In Use	enroute : on vectors
Flight Plan	IFR
Aircraft 2
Operator	common carrier : air carrier
Make Model Name	Commercial Fixed Wing
Operating Under FAR Part	Part 121
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Experience	flight time last 90 days : 150 flight time total : 25000 flight time type : 750
ASRS Report	274412
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : atp pilot : commercial pilot : instrument
Events
Anomaly	altitude deviation : excursion from assigned altitude non adherence : clearance non adherence : far other anomaly other
Independent Detector	aircraft equipment other aircraft equipment : unspecified
Resolutory Action	flight crew : took evasive action
Consequence	faa : reviewed incident with flight crew Other
Supplementary
Primary Problem	ATC Human Performance
Air Traffic Incident	Inter Facility Coordination Failure Operational Deviation

Narrative:

We were on ATC vectors toward tul for re-routing to dfw. Several heading vectors and changes were made because of dfw arrival delays. Both aircraft were at 350 degrees. Situation developing unbeknownst to ZFW or flight crew of air carrier was: another aircraft from ZKC flew into ZFW space with possible no radio contact. Sequence of events: ATC issued us a heading of 350 degrees.with urgency in the controller's voice, he then issued a heading of 030 degrees. At the same time I observed a yellow target on the TCASII scope. No voice. Position approximately. 1-2 O'clock position. With strong urgency in the controller's voice, he cleared us to FL310. At the same time the TCASII voice mode said 'traffic, traffic.' thus confusing his clearance to 310 degrees. The copilot increased his bank rate to approximately 40 degrees stating 'something is not right.' at the same time I pulled the spoiler handle full aft and stated 'take it down.' at approximately the same time the TCASII voice mode stated, 'descend, descend.' we descended at a rate of approximately 6000 FPM until reaching FL280. Only then was I able to confirm the clearance altitude because both the ATC controller and I continued to stop on each others xmissions. Fortunately, the seat belt sign was on and all passenger were in their seats. All but one flight attendant were seated. She said that she left the floor but was not hurt. I have requested ATC report.

Original NASA ASRS Text

Title: LGT GIVEN CLRNC TO DSND AS TCASII RA SOUNDS.

Narrative: WE WERE ON ATC VECTORS TOWARD TUL FOR RE-RTING TO DFW. SEVERAL HDG VECTORS AND CHANGES WERE MADE BECAUSE OF DFW ARR DELAYS. BOTH ACFT WERE AT 350 DEGS. SIT DEVELOPING UNBEKNOWNST TO ZFW OR FLC OF ACR WAS: ANOTHER ACFT FROM ZKC FLEW INTO ZFW SPACE WITH POSSIBLE NO RADIO CONTACT. SEQUENCE OF EVENTS: ATC ISSUED US A HDG OF 350 DEGS.WITH URGENCY IN THE CTLR'S VOICE, HE THEN ISSUED A HDG OF 030 DEGS. AT THE SAME TIME I OBSERVED A YELLOW TARGET ON THE TCASII SCOPE. NO VOICE. POS APPROX. 1-2 O'CLOCK POS. WITH STRONG URGENCY IN THE CTLR'S VOICE, HE CLRED US TO FL310. AT THE SAME TIME THE TCASII VOICE MODE SAID 'TFC, TFC.' THUS CONFUSING HIS CLRNC TO 310 DEGS. THE COPLT INCREASED HIS BANK RATE TO APPROX 40 DEGS STATING 'SOMETHING IS NOT RIGHT.' AT THE SAME TIME I PULLED THE SPOILER HANDLE FULL AFT AND STATED 'TAKE IT DOWN.' AT APPROX THE SAME TIME THE TCASII VOICE MODE STATED, 'DSND, DSND.' WE DSNDED AT A RATE OF APPROX 6000 FPM UNTIL REACHING FL280. ONLY THEN WAS I ABLE TO CONFIRM THE CLRNC ALT BECAUSE BOTH THE ATC CTLR AND I CONTINUED TO STOP ON EACH OTHERS XMISSIONS. FORTUNATELY, THE SEAT BELT SIGN WAS ON AND ALL PAX WERE IN THEIR SEATS. ALL BUT ONE FLT ATTENDANT WERE SEATED. SHE SAID THAT SHE LEFT THE FLOOR BUT WAS NOT HURT. I HAVE REQUESTED ATC RPT.

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.