Less than standard separation between small aircraft and air carrier on approach control frequency.

Attributes
ACN	117656
Time
Date	198907
Day	Sat
Local Time Of Day	1201 To 1800
Place
Locale Reference	airport : cvg
State Reference	OH
Altitude	msl bound lower : 6450 msl bound upper : 7000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	tracon : cvg artcc : zob
Operator	common carrier : air carrier
Make Model Name	Medium Large Transport, Low Wing, 2 Turbojet Eng
Flight Phase	cruise other cruise other other
Flight Plan	IFR
Aircraft 2
Operator	general aviation : personal
Make Model Name	Small Aircraft, Low Wing, 1 Eng, Retractable Gear
Flight Phase	cruise other
Flight Plan	VFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : instrument pilot : commercial pilot : atp
Experience	flight time last 90 days : 150 flight time total : 8000 flight time type : 3500
ASRS Report	117656
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : atp
Experience	flight time last 90 days : 210 flight time total : 3600 flight time type : 700
ASRS Report	117800
Events
Anomaly	altitude deviation : excursion from assigned altitude conflict : airborne less severe non adherence : required legal separation other anomaly other
Independent Detector	other controllera
Resolutory Action	controller : issued new clearance other
Consequence	Other
Miss Distance	horizontal : 1500 vertical : 300
Supplementary
Primary Problem	Ambiguous
Air Traffic Incident	Operational Error other

Narrative:

We were cleared by cvg approach to descend from 7000 to 4000' MSL. When passing 6500' MSL approach control told us to climb immediately to 7000' MSL as we had 10 O'clock traffic, 3 NM, converging at 6000' MSL. We initiated a climb back to 7000' MSL and I saw an small aircraft go slightly behind us. The controller said there was a mix up. I asked if we were part of the mix up and he responded with something about similar call signs. There was a company flight Y on frequency at the same time. I feel we were given flight Y's descent. I did read back the descent clearance and call sign. Possibly the controller was under pressure and also there were similar call signs on a frequency at the same time. There should not be similar call signs on a frequency at the same time unless one is delayed. Supplemental information from acn 117800: controller stated he confused similar call sign aircraft and descent wasn't for us.

Original NASA ASRS Text

Title: LESS THAN STANDARD SEPARATION BETWEEN SMA AND ACR ON APCH CTL FREQ.

Narrative: WE WERE CLRED BY CVG APCH TO DSND FROM 7000 TO 4000' MSL. WHEN PASSING 6500' MSL APCH CTL TOLD US TO CLB IMMEDIATELY TO 7000' MSL AS WE HAD 10 O'CLOCK TFC, 3 NM, CONVERGING AT 6000' MSL. WE INITIATED A CLB BACK TO 7000' MSL AND I SAW AN SMA GO SLIGHTLY BEHIND US. THE CTLR SAID THERE WAS A MIX UP. I ASKED IF WE WERE PART OF THE MIX UP AND HE RESPONDED WITH SOMETHING ABOUT SIMILAR CALL SIGNS. THERE WAS A COMPANY FLT Y ON FREQ AT THE SAME TIME. I FEEL WE WERE GIVEN FLT Y'S DSCNT. I DID READ BACK THE DSCNT CLRNC AND CALL SIGN. POSSIBLY THE CTLR WAS UNDER PRESSURE AND ALSO THERE WERE SIMILAR CALL SIGNS ON A FREQ AT THE SAME TIME. THERE SHOULD NOT BE SIMILAR CALL SIGNS ON A FREQ AT THE SAME TIME UNLESS ONE IS DELAYED. SUPPLEMENTAL INFO FROM ACN 117800: CTLR STATED HE CONFUSED SIMILAR CALL SIGN ACFT AND DSCNT WASN'T FOR US.

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.