Air carrier X had less than standard separation from military Y. System error.

Attributes
ACN	174339
Time
Date	199102
Day	Sat
Local Time Of Day	0601 To 1200
Place
Locale Reference	atc facility : mtu
State Reference	UT
Altitude	msl bound lower : 23500 msl bound upper : 35000
Environment
Flight Conditions	IMC
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zlc
Operator	common carrier : air carrier
Make Model Name	Widebody, Low Wing, 2 Turbojet Eng
Navigation In Use	Other Other
Flight Phase	climbout : intermediate altitude
Route In Use	enroute : direct
Flight Plan	IFR
Aircraft 2
Operator	other
Make Model Name	Experimental
Flight Phase	cruise other
Route In Use	enroute : direct
Flight Plan	IFR
Person 1
Affiliation	government : faa
Function	controller : radar
Qualification	controller : radar
Experience	controller non radar : 2 controller radar : 3
ASRS Report	174339
Person 2
Affiliation	government : faa
Function	controller : radar
Qualification	controller : radar
Events
Anomaly	conflict : airborne less severe non adherence : published procedure non adherence : required legal separation
Independent Detector	other controllera
Resolutory Action	controller : issued new clearance other
Consequence	faa : investigated
Miss Distance	horizontal : 18000 vertical : 1500
Supplementary
Primary Problem	ATC Human Performance
Air Traffic Incident	Operational Error

Narrative:

Air carrier X was issued a clearance to stop at FL330 for military Y traffic at FL350. Air carrier X continued climb through FL330 to FL380 resulting in loss of sep with utah 51. Closest proximity was 1500' and 3 mi. Review of tape revealed no readback from air carrier X. Air carrier X was noticed immediately climbing through FL330 and was issued clearance to maintain FL330. The crew acknowledged. I feel human error contributed greatly to this situation. I, as the controller, did not verify the readback. Possibly if the crew were paying more attention, the clearance would have been acknowledged the first time it was issued. Callback conversation with reporter revealed the following: reporter stated he was an fpl with 3 yrs radar and 2 yrs non radar experience. The incident happened 2 mins after position relief. C/a did not activate because FL330 was entered into the data block. The reporter had failed to receive an acknowledgement of the stop at FL330. Relieving controller heard FL330 issued during the position relief briefing and assumed the air carrier X flight crew had acknowledged.

Original NASA ASRS Text

Title: ACR X HAD LESS THAN STANDARD SEPARATION FROM MIL Y. SYSTEM ERROR.

Narrative: ACR X WAS ISSUED A CLRNC TO STOP AT FL330 FOR MIL Y TFC AT FL350. ACR X CONTINUED CLB THROUGH FL330 TO FL380 RESULTING IN LOSS OF SEP WITH UTAH 51. CLOSEST PROX WAS 1500' AND 3 MI. REVIEW OF TAPE REVEALED NO READBACK FROM ACR X. ACR X WAS NOTICED IMMEDIATELY CLBING THROUGH FL330 AND WAS ISSUED CLRNC TO MAINTAIN FL330. THE CREW ACKNOWLEDGED. I FEEL HUMAN ERROR CONTRIBUTED GREATLY TO THIS SITUATION. I, AS THE CTLR, DID NOT VERIFY THE READBACK. POSSIBLY IF THE CREW WERE PAYING MORE ATTN, THE CLRNC WOULD HAVE BEEN ACKNOWLEDGED THE FIRST TIME IT WAS ISSUED. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING: RPTR STATED HE WAS AN FPL WITH 3 YRS RADAR AND 2 YRS NON RADAR EXPERIENCE. THE INCIDENT HAPPENED 2 MINS AFTER POS RELIEF. C/A DID NOT ACTIVATE BECAUSE FL330 WAS ENTERED INTO THE DATA BLOCK. THE RPTR HAD FAILED TO RECEIVE AN ACKNOWLEDGEMENT OF THE STOP AT FL330. RELIEVING CTLR HEARD FL330 ISSUED DURING THE POS RELIEF BRIEFING AND ASSUMED THE ACR X FLT CREW HAD ACKNOWLEDGED.

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.