Air carrier X climb to occupied altitude had less than standard separation from air carrier Y. Pilot...

Attributes
ACN	302550
Time
Date	199504
Day	Sat
Local Time Of Day	1201 To 1800
Place
Locale Reference	atc facility : lyh
State Reference	VA
Altitude	msl bound lower : 24000 msl bound upper : 24000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zdc
Operator	common carrier : air carrier
Make Model Name	Commercial Fixed Wing
Operating Under FAR Part	Part 121
Navigation In Use	Other Other
Flight Phase	cruise other
Route In Use	enroute : direct
Flight Plan	IFR
Aircraft 2
Operator	common carrier : air carrier
Make Model Name	Commercial Fixed Wing
Operating Under FAR Part	Part 121
Flight Phase	cruise other
Route In Use	enroute : direct
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Experience	flight time last 90 days : 210 flight time total : 12000 flight time type : 1200
ASRS Report	302550
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : instrument pilot : commercial
Events
Anomaly	altitude deviation : overshoot conflict : airborne less severe non adherence : clearance non adherence : required legal separation
Independent Detector	other flight crewa
Resolutory Action	none taken : anomaly accepted
Consequence	faa : investigated
Miss Distance	horizontal : 12000 vertical : 0
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

Air carrier X was cleared to FL240 and told 'traffic at FL240, upon clearing, higher available.' arriving at FL240 was asked 'what altitude were you assigned?' to which we answered 'FL240.' TCASII indicated (no alerts) air carrier Y at FL240 within estimated 2 mi passing to our left rear eastbound. We are wbound. No other xmissions occurred concerning the above. We were either cleared in error or misunderstood the clearance to FL240 with traffic call at FL240. Procedures provide PNF set and PF confirm altitude settings. But, there was only 2 of us and we both misunderstood, or didn't see strange clearance and traffic call at same altitude.

Original NASA ASRS Text

Title: ACR X CLB TO OCCUPIED ALT HAD LTSS FROM ACR Y. PLTDEV.

Narrative: ACR X WAS CLRED TO FL240 AND TOLD 'TFC AT FL240, UPON CLRING, HIGHER AVAILABLE.' ARRIVING AT FL240 WAS ASKED 'WHAT ALT WERE YOU ASSIGNED?' TO WHICH WE ANSWERED 'FL240.' TCASII INDICATED (NO ALERTS) ACR Y AT FL240 WITHIN ESTIMATED 2 MI PASSING TO OUR L REAR EBOUND. WE ARE WBOUND. NO OTHER XMISSIONS OCCURRED CONCERNING THE ABOVE. WE WERE EITHER CLRED IN ERROR OR MISUNDERSTOOD THE CLRNC TO FL240 WITH TFC CALL AT FL240. PROCS PROVIDE PNF SET AND PF CONFIRM ALT SETTINGS. BUT, THERE WAS ONLY 2 OF US AND WE BOTH MISUNDERSTOOD, OR DIDN'T SEE STRANGE CLRNC AND TFC CALL AT SAME ALT.

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.

Air carrier X climb to occupied altitude had less than standard separation from air carrier Y. Pilot deviation.