Clearance for another aircraft intercepted. Altitude deviation. Less than standard separation.

Attributes
ACN	123263
Time
Date	198909
Day	Thu
Local Time Of Day	1201 To 1800
Place
Locale Reference	atc facility : atl
State Reference	GA
Altitude	msl bound lower : 19600 msl bound upper : 20000
Environment
Flight Conditions	IMC
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : ztl tower : oak
Operator	common carrier : air carrier
Make Model Name	Medium Large Transport, Low Wing, 2 Turbojet Eng
Flight Phase	climbout : intermediate altitude cruise other
Route In Use	enroute : on vectors
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Experience	flight time last 90 days : 150 flight time total : 10000 flight time type : 4000
ASRS Report	123263
Person 2
Affiliation	government : faa
Function	controller : radar
Qualification	controller : radar
Events
Anomaly	altitude deviation : overshoot non adherence : required legal separation non adherence : clearance
Independent Detector	other controllera
Resolutory Action	none taken : anomaly accepted
Consequence	Other
Supplementary
Primary Problem	ATC Human Performance
Air Traffic Incident	Operational Error Pilot Deviation other

Narrative:

We received a clearance to 19,000' which was changed to 18,000'. Shortly thereafter, the controller (ZTL frequency 134.95) asked if we could give him a good rate thru 19,000'. We replied affirmative and asked what altitude he wished us to climb to. He replied FL230. We acknowledged climb to 230, good rate thru 19,000. As we were passing 19,600 the controller asked our altitude. We told him and advised him that we had read back the clearance. He told us that this clearance was meant for another aircraft (who apparently never responded). We were given an immediate turn to 360 (originally heading 090) and told to level at 20,000 which we did. As we were doing this the controller issued heading and altitude instructions to an air carrier aircraft that we apparently were in conflict with.

Original NASA ASRS Text

Title: CLRNC FOR ANOTHER ACFT INTERCEPTED. ALT DEVIATION. LESS THAN STANDARD SEPARATION.

Narrative: WE RECEIVED A CLRNC TO 19,000' WHICH WAS CHANGED TO 18,000'. SHORTLY THEREAFTER, THE CTLR (ZTL FREQ 134.95) ASKED IF WE COULD GIVE HIM A GOOD RATE THRU 19,000'. WE REPLIED AFFIRMATIVE AND ASKED WHAT ALT HE WISHED US TO CLIMB TO. HE REPLIED FL230. WE ACKNOWLEDGED CLIMB TO 230, GOOD RATE THRU 19,000. AS WE WERE PASSING 19,600 THE CTLR ASKED OUR ALT. WE TOLD HIM AND ADVISED HIM THAT WE HAD READ BACK THE CLRNC. HE TOLD US THAT THIS CLRNC WAS MEANT FOR ANOTHER ACFT (WHO APPARENTLY NEVER RESPONDED). WE WERE GIVEN AN IMMEDIATE TURN TO 360 (ORIGINALLY HDG 090) AND TOLD TO LEVEL AT 20,000 WHICH WE DID. AS WE WERE DOING THIS THE CTLR ISSUED HDG AND ALT INSTRUCTIONS TO AN ACR ACFT THAT WE APPARENTLY WERE IN CONFLICT WITH.

Data retrieved from NASA's ASRS site as of August 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.