MD80 crew responds to TCASII RA during STAR at dfw.

Attributes
ACN	437893
Time
Date	199905
Day	Sat
Local Time Of Day	1201 To 1800
Place
Locale Reference	navaid : ttt.vor
State Reference	TX
Altitude	msl bound lower : 9000 msl bound upper : 11000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zfw.artcc
Operator	common carrier : air carrier
Make Model Name	MD-80 Super 80
Operating Under FAR Part	Part 121
Navigation In Use	other other vortac
Flight Phase	descent : intermediate altitude
Route In Use	arrival star : wilbr two
Flight Plan	IFR
Aircraft 2
Controlling Facilities	artcc : zfw.artcc
Operator	general aviation : personal
Make Model Name	Any Unknown or Unlisted Aircraft Manufacturer
Operating Under FAR Part	Part 91
Navigation In Use	other
Flight Phase	cruise : level
Flight Plan	VFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
ASRS Report	437893
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : commercial pilot : instrument pilot : multi engine
Events
Anomaly	altitude deviation : excursion from assigned altitude conflict : nmac conflict : airborne critical non adherence : required legal separation
Independent Detector	aircraft equipment : tcas other flight crewa
Resolutory Action	flight crew : took evasive action
Supplementary
Problem Areas	ATC Human Performance Airspace Structure Chart Or Publication
Primary Problem	Airspace Structure
Air Traffic Incident	Operational Error

Narrative:

TTT 042 degree radial 053 DME. Filed to dfw via byp 3 arrival. Reclred wilbr 2 due to skydiving aircraft near byp. Found 1 skydive aircraft on TCASII when level 11000 ft on wilbr 2 at radial/DME fix indicated above. I looked at TCASII display to see another aircraft pop up on TCASII display behind first skydive aircraft for just a moment, then it disappeared from screen. Seconds later received TCASII RA with a 'descend, descend' message and vsi showing 1500 FPM descent. Found aircraft visually as I descended. It corresponded to the second aircraft that briefly appeared on TCASII screen. After approximately 1000 ft descent, received 'monitor vertical speed' message, followed shortly thereafter by another 'descend, descend' message. I continued descent as aircraft passed abeam to the right. Continued descent while waiting for 'clear of conflict' message. After reaching about 9000 ft, with the aircraft behind us, I decided to return to 11000 ft. We did not receive a 'clear of conflict' message. ZFW advised of RA, and we were cleared to dfw approach control. The mix of skydiving aircraft and dfw inbound arrival aircraft in the area around byp is unacceptable. The wilbr arrival does not provide enough lateral separation between skydive aircraft and dfw arrival traffic.

Original NASA ASRS Text

Title: MD80 CREW RESPONDS TO TCASII RA DURING STAR AT DFW.

Narrative: TTT 042 DEG RADIAL 053 DME. FILED TO DFW VIA BYP 3 ARR. RECLRED WILBR 2 DUE TO SKYDIVING ACFT NEAR BYP. FOUND 1 SKYDIVE ACFT ON TCASII WHEN LEVEL 11000 FT ON WILBR 2 AT RADIAL/DME FIX INDICATED ABOVE. I LOOKED AT TCASII DISPLAY TO SEE ANOTHER ACFT POP UP ON TCASII DISPLAY BEHIND FIRST SKYDIVE ACFT FOR JUST A MOMENT, THEN IT DISAPPEARED FROM SCREEN. SECONDS LATER RECEIVED TCASII RA WITH A 'DSND, DSND' MESSAGE AND VSI SHOWING 1500 FPM DSCNT. FOUND ACFT VISUALLY AS I DSNDED. IT CORRESPONDED TO THE SECOND ACFT THAT BRIEFLY APPEARED ON TCASII SCREEN. AFTER APPROX 1000 FT DSCNT, RECEIVED 'MONITOR VERT SPD' MESSAGE, FOLLOWED SHORTLY THEREAFTER BY ANOTHER 'DSND, DSND' MESSAGE. I CONTINUED DSCNT AS ACFT PASSED ABEAM TO THE R. CONTINUED DSCNT WHILE WAITING FOR 'CLR OF CONFLICT' MESSAGE. AFTER REACHING ABOUT 9000 FT, WITH THE ACFT BEHIND US, I DECIDED TO RETURN TO 11000 FT. WE DID NOT RECEIVE A 'CLR OF CONFLICT' MESSAGE. ZFW ADVISED OF RA, AND WE WERE CLRED TO DFW APCH CTL. THE MIX OF SKYDIVING ACFT AND DFW INBOUND ARR ACFT IN THE AREA AROUND BYP IS UNACCEPTABLE. THE WILBR ARR DOES NOT PROVIDE ENOUGH LATERAL SEPARATION BTWN SKYDIVE ACFT AND DFW ARR TFC.

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.