Possible transposition of call signs causes holding incident.

Attributes
ACN	295873
Time
Date	199502
Day	Fri
Local Time Of Day	1201 To 1800
Place
Locale Reference	atc facility : buj
State Reference	TX
Altitude	msl bound lower : 24000 msl bound upper : 25000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zfw
Operator	common carrier : air carrier
Make Model Name	Any Unknown or Unlisted Aircraft Manufacturer
Operating Under FAR Part	Part 121
Navigation In Use	Other Other
Flight Phase	other
Route In Use	arrival other arrival star : star enroute airway : zfw
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	other
Route In Use	arrival other arrival star : star
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : atp
Experience	flight time last 90 days : 200 flight time total : 4100 flight time type : 1200
ASRS Report	295873
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Experience	flight time last 90 days : 300 flight time total : 8000 flight time type : 250
ASRS Report	295658
Events
Anomaly	conflict : airborne less severe non adherence : required legal separation other anomaly other
Independent Detector	other controllera other flight crewa
Resolutory Action	controller : issued new clearance other
Consequence	Other
Miss Distance	horizontal : 18000 vertical : 0
Supplementary
Primary Problem	ATC Human Performance
Air Traffic Incident	Operational Error

Narrative:

En route from phl to dfw, on the blue ridge 6 arrival into dfw, we were cleared to hold at conny intersection as published at FL280. Approaching conny, we were cleared by the controller to descend to FL250 and maintain that in the holding pattern. We repeated back FL250 to the controller, and she said, no, that we were cleared down to FL240. When we got to FL240, we noticed another aircraft (a B-727, I believe) in the same holding pattern. He was ahead of us at conny intersection making his right hand turn and he was at the same altitude. As we noticed this and were about to call center, the center controller asked our altitude, we said FL240. She said to climb back up to FL250 and told us of the aircraft at the same altitude. We told her that, we had descended to FL240 initially because she told us to and that we had read back FL240 and nothing was said to us when we read it back. We were at the same altitude, but basically following the other aircraft in the holding pattern. Fortunately it was VMC, not IMC, though we did not know if our speed was greater than the other aircraft. I believe that since both aircraft were company airlines, the controller confused the call signs and the altitude. Maybe we were originally supposed to go FL250 (as she originally said) and the other aircraft was cleared to FL240 almost simultaneously in the stack.

Original NASA ASRS Text

Title: POSSIBLE TRANSPOSITION OF CALL SIGNS CAUSES HOLDING INCIDENT.

Narrative: ENRTE FROM PHL TO DFW, ON THE BLUE RIDGE 6 ARR INTO DFW, WE WERE CLRED TO HOLD AT CONNY INTXN AS PUBLISHED AT FL280. APCHING CONNY, WE WERE CLRED BY THE CTLR TO DSND TO FL250 AND MAINTAIN THAT IN THE HOLDING PATTERN. WE REPEATED BACK FL250 TO THE CTLR, AND SHE SAID, NO, THAT WE WERE CLRED DOWN TO FL240. WHEN WE GOT TO FL240, WE NOTICED ANOTHER ACFT (A B-727, I BELIEVE) IN THE SAME HOLDING PATTERN. HE WAS AHEAD OF US AT CONNY INTXN MAKING HIS R HAND TURN AND HE WAS AT THE SAME ALT. AS WE NOTICED THIS AND WERE ABOUT TO CALL CTR, THE CTR CTLR ASKED OUR ALT, WE SAID FL240. SHE SAID TO CLB BACK UP TO FL250 AND TOLD US OF THE ACFT AT THE SAME ALT. WE TOLD HER THAT, WE HAD DSNDED TO FL240 INITIALLY BECAUSE SHE TOLD US TO AND THAT WE HAD READ BACK FL240 AND NOTHING WAS SAID TO US WHEN WE READ IT BACK. WE WERE AT THE SAME ALT, BUT BASICALLY FOLLOWING THE OTHER ACFT IN THE HOLDING PATTERN. FORTUNATELY IT WAS VMC, NOT IMC, THOUGH WE DID NOT KNOW IF OUR SPD WAS GREATER THAN THE OTHER ACFT. I BELIEVE THAT SINCE BOTH ACFT WERE COMPANY AIRLINES, THE CTLR CONFUSED THE CALL SIGNS AND THE ALT. MAYBE WE WERE ORIGINALLY SUPPOSED TO GO FL250 (AS SHE ORIGINALLY SAID) AND THE OTHER ACFT WAS CLRED TO FL240 ALMOST SIMULTANEOUSLY IN THE STACK.

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.