Potential conflict less than standard separation between climbing descending traffic.

Attributes
ACN	188583
Time
Date	199109
Day	Mon
Local Time Of Day	1201 To 1800
Place
Locale Reference	atc facility : ogd
State Reference	UT
Altitude	msl bound lower : 28300 msl bound upper : 28300
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zlc artcc : zoa
Operator	common carrier : air carrier
Make Model Name	Large Transport, Low Wing, 2 Turbojet Eng
Navigation In Use	Other Other
Flight Phase	descent other
Flight Plan	IFR
Aircraft 2
Operator	common carrier : air carrier
Make Model Name	Any Unknown or Unlisted Aircraft Manufacturer
Flight Phase	climbout : intermediate altitude
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : instrument pilot : flight engineer pilot : commercial pilot : atp
Experience	flight time last 90 days : 190 flight time total : 18000 flight time type : 190
ASRS Report	188583
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : atp
Events
Anomaly	conflict : airborne less severe non adherence : required legal separation non adherence : published procedure other anomaly other
Independent Detector	aircraft equipment other aircraft equipment : unspecified other controllera other flight crewa
Resolutory Action	none taken : anomaly accepted
Consequence	Other
Miss Distance	horizontal : 12000 vertical : 200
Supplementary
Primary Problem	ATC Human Performance
Air Traffic Incident	Operational Error Pilot Deviation
Situations
ATC Facility	procedure or policy : unspecified

Narrative:

Clearance was from FL410 to maintain FL260, cross 20 north of ogd at 17000 ft. The large transport was equipped with TCASII and it was in use. Traffic was observed approaching northbound at approximately 30 NM range on the TCASII. Visual sighting at approximately 10 mi. We continued descent and at 28300 ft, ATC called and advised to 'maintain FL290'. At about this time the 'traffic' call was issued from the TCASII (no RA). The aircraft climbing out passed off our right wing at an estimated 2 mi lateral separation and altitude of 28500 ft. No evasive action was necessary. We did not climb back to FL290 as the traffic was just passing us and the clearance was obviously late in coming. ATC then cleared us to continue on down to 17000 ft. I suspect this incident violated ATC separation standards and in my opinion the instruction to 'maintain FL290' was late in coming. I was not aware of what altitude the northbound aircraft was cleared to. I did not at any time feel that there was any significant threat to safe operation since the traffic was in sight at all times and was also being observed on the TCASII. If anything, this certainly reinforced my belief that TCASII is one of the best safety enhancing items to be put on aircraft since radar.

Original NASA ASRS Text

Title: POTENTIAL CONFLICT LTSS BTWN CLBING DSNDING TFC.

Narrative: CLRNC WAS FROM FL410 TO MAINTAIN FL260, CROSS 20 N OF OGD AT 17000 FT. THE LGT WAS EQUIPPED WITH TCASII AND IT WAS IN USE. TFC WAS OBSERVED APCHING NBOUND AT APPROX 30 NM RANGE ON THE TCASII. VISUAL SIGHTING AT APPROX 10 MI. WE CONTINUED DSCNT AND AT 28300 FT, ATC CALLED AND ADVISED TO 'MAINTAIN FL290'. AT ABOUT THIS TIME THE 'TFC' CALL WAS ISSUED FROM THE TCASII (NO RA). THE ACFT CLBING OUT PASSED OFF OUR R WING AT AN ESTIMATED 2 MI LATERAL SEPARATION AND ALT OF 28500 FT. NO EVASIVE ACTION WAS NECESSARY. WE DID NOT CLB BACK TO FL290 AS THE TFC WAS JUST PASSING US AND THE CLRNC WAS OBVIOUSLY LATE IN COMING. ATC THEN CLRED US TO CONTINUE ON DOWN TO 17000 FT. I SUSPECT THIS INCIDENT VIOLATED ATC SEPARATION STANDARDS AND IN MY OPINION THE INSTRUCTION TO 'MAINTAIN FL290' WAS LATE IN COMING. I WAS NOT AWARE OF WHAT ALT THE NBOUND ACFT WAS CLRED TO. I DID NOT AT ANY TIME FEEL THAT THERE WAS ANY SIGNIFICANT THREAT TO SAFE OP SINCE THE TFC WAS IN SIGHT AT ALL TIMES AND WAS ALSO BEING OBSERVED ON THE TCASII. IF ANYTHING, THIS CERTAINLY REINFORCED MY BELIEF THAT TCASII IS ONE OF THE BEST SAFETY ENHANCING ITEMS TO BE PUT ON ACFT SINCE RADAR.

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.