Air carrier medium large transport less than standard separation but apparently short of a 'deal'.

Attributes
ACN	190546
Time
Date	199110
Day	Wed
Local Time Of Day	0601 To 1200
Place
Locale Reference	atc facility : abq
State Reference	NM
Altitude	msl bound lower : 23000 msl bound upper : 26000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zab
Operator	common carrier : air carrier
Make Model Name	Medium Large Transport, Low Wing, 2 Turbojet Eng
Flight Phase	descent other
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : commercial pilot : atp
Experience	flight time last 90 days : 240 flight time total : 12000 flight time type : 10500
ASRS Report	190546
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : atp
Events
Anomaly	non adherence : required legal separation other anomaly other
Independent Detector	other controllera other flight crewa
Resolutory Action	controller : issued new clearance
Consequence	Other
Supplementary
Primary Problem	ATC Human Performance
Air Traffic Incident	Operational Error

Narrative:

Initial cruise altitude was 350. Clearance was given to 260. After reaching 260, next clearance was for descend through 230 discretion to 150. Almost immediately after acknowledgement of clearance, the clearance was amended to be out of 230 within 1 min. Descent had been initiated prior to amended clearance, so descent was increased to 4500 FPM. We were through 240 when center called back and amended clearance again to stop descent at 250. I told center that we were through 240 and asked for clarification of exactly what (altitude) they wanted. We were told to continue descent through 230, cross 35 east of abq at 150. Through 210 we observed traffic passing over us at 240. The aircraft involved were never in close proximity. The conflict was within the en route separation requirements I suppose. However, ATC created a few intense moments as the clrncs and acknowledgements were all back to back and traffic was never pointed out to us.

Original NASA ASRS Text

Title: ACR MLG LTSS BUT APPARENTLY SHORT OF A 'DEAL'.

Narrative: INITIAL CRUISE ALT WAS 350. CLRNC WAS GIVEN TO 260. AFTER REACHING 260, NEXT CLRNC WAS FOR DSND THROUGH 230 DISCRETION TO 150. ALMOST IMMEDIATELY AFTER ACKNOWLEDGEMENT OF CLRNC, THE CLRNC WAS AMENDED TO BE OUT OF 230 WITHIN 1 MIN. DSCNT HAD BEEN INITIATED PRIOR TO AMENDED CLRNC, SO DSCNT WAS INCREASED TO 4500 FPM. WE WERE THROUGH 240 WHEN CENTER CALLED BACK AND AMENDED CLRNC AGAIN TO STOP DSCNT AT 250. I TOLD CENTER THAT WE WERE THROUGH 240 AND ASKED FOR CLARIFICATION OF EXACTLY WHAT (ALT) THEY WANTED. WE WERE TOLD TO CONTINUE DSCNT THROUGH 230, CROSS 35 E OF ABQ AT 150. THROUGH 210 WE OBSERVED TFC PASSING OVER US AT 240. THE ACFT INVOLVED WERE NEVER IN CLOSE PROX. THE CONFLICT WAS WITHIN THE ENRTE SEPARATION REQUIREMENTS I SUPPOSE. HOWEVER, ATC CREATED A FEW INTENSE MOMENTS AS THE CLRNCS AND ACKNOWLEDGEMENTS WERE ALL BACK TO BACK AND TFC WAS NEVER POINTED OUT TO US.

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.