B737 flight crew with ZTL experienced TCASII RA during climb clearance from FL240 to FL290.

Attributes
ACN	640561
Time
Date	200411
Day	Tue
Local Time Of Day	1201 To 1800
Place
Locale Reference	atc facility : ztl.artcc
State Reference	GA
Altitude	msl bound lower : 24000 msl bound upper : 29000
Environment
Flight Conditions	IMC
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : ztl.artcc
Operator	common carrier : air carrier
Make Model Name	B737-500
Operating Under FAR Part	Part 121
Navigation In Use	other
Flight Phase	cruise : enroute altitude change
Flight Plan	IFR
Aircraft 2
Controlling Facilities	artcc : ztl.artcc
Make Model Name	Commercial Fixed Wing
Flight Phase	cruise : level
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : first officer
Experience	flight time last 90 days : 3000 flight time total : 11500 flight time type : 220
ASRS Report	640561
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Experience	flight time last 90 days : 5000 flight time total : 20000 flight time type : 250
ASRS Report	640562
Events
Anomaly	conflict : airborne critical non adherence : required legal separation
Independent Detector	atc equipment : conflict alert aircraft equipment : tcas other controllera other flight crewa other flight crewb
Resolutory Action	controller : issued new clearance controller : separated traffic flight crew : took evasive action
Consequence	faa : investigated Other
Miss Distance	horizontal : 12000
Supplementary
Problem Areas	Flight Crew Human Performance ATC Human Performance
Primary Problem	Ambiguous

Narrative:

ZTL (125.62) cleared flight aircraft X from FL240 to FL250, then to FL290. Both pilots heard the altitude clrncs and then readback clrncs and were confirmed and then readback by first officer. Each altitude was set, then reset on MCP and confirmed by captain. Passing FL250 aircraft received a TA with another aircraft less than 20 mi on radar screen. Aircraft subsequently received an RA initially accompanied by 'monitor vertical speed' and red vertical climb warnings, followed by 'descend' commands. The aircraft was immediately flown into a descent from FL250 to FL240 in response to RA commands. The autoplt was disengaged during the descent. Simultaneously with the RA commands, the ATC controller said 'aircraft X, maintain FL240 and what altitude were you assigned?' we responded FL290. The controller said 'descend immediately to FL240 traffic at 2 mi.' we followed RA commands to FL240 and received 'clear of conflict' at FL240. Prior to conflict aircraft had been cleared and was direct to spa with LNAV and VNAV engaged and autoplt on. Within several mins of conflict resolution, controller voices changed and we assumed an actual controller change had occurred.

Original NASA ASRS Text

Title: B737 FLT CREW WITH ZTL EXPERIENCED TCASII RA DURING CLB CLRNC FROM FL240 TO FL290.

Narrative: ZTL (125.62) CLRED FLT ACFT X FROM FL240 TO FL250, THEN TO FL290. BOTH PLTS HEARD THE ALT CLRNCS AND THEN READBACK CLRNCS AND WERE CONFIRMED AND THEN READBACK BY FO. EACH ALT WAS SET, THEN RESET ON MCP AND CONFIRMED BY CAPT. PASSING FL250 ACFT RECEIVED A TA WITH ANOTHER ACFT LESS THAN 20 MI ON RADAR SCREEN. ACFT SUBSEQUENTLY RECEIVED AN RA INITIALLY ACCOMPANIED BY 'MONITOR VERT SPD' AND RED VERT CLB WARNINGS, FOLLOWED BY 'DSND' COMMANDS. THE ACFT WAS IMMEDIATELY FLOWN INTO A DSCNT FROM FL250 TO FL240 IN RESPONSE TO RA COMMANDS. THE AUTOPLT WAS DISENGAGED DURING THE DSCNT. SIMULTANEOUSLY WITH THE RA COMMANDS, THE ATC CTLR SAID 'ACFT X, MAINTAIN FL240 AND WHAT ALT WERE YOU ASSIGNED?' WE RESPONDED FL290. THE CTLR SAID 'DSND IMMEDIATELY TO FL240 TFC AT 2 MI.' WE FOLLOWED RA COMMANDS TO FL240 AND RECEIVED 'CLR OF CONFLICT' AT FL240. PRIOR TO CONFLICT ACFT HAD BEEN CLRED AND WAS DIRECT TO SPA WITH LNAV AND VNAV ENGAGED AND AUTOPLT ON. WITHIN SEVERAL MINS OF CONFLICT RESOLUTION, CTLR VOICES CHANGED AND WE ASSUMED AN ACTUAL CTLR CHANGE HAD OCCURRED.

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.