ZME controller describes a near loss of separation saved by TCASII at FL270.

Attributes
ACN	616153
Time
Date	200405
Day	Sat
Local Time Of Day	1201 To 1800
Place
Locale Reference	navaid : dyr.vortac
State Reference	TN
Altitude	msl single value : 27000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zme.artcc
Operator	common carrier : air carrier
Make Model Name	MD-80 Series (DC-9-80) Undifferentiated or Other Model
Operating Under FAR Part	Part 121
Flight Phase	climbout : intermediate altitude
Flight Plan	IFR
Aircraft 2
Controlling Facilities	artcc : zme.artcc
Operator	common carrier : air carrier
Make Model Name	MD-80 Series (DC-9-80) Undifferentiated or Other Model
Operating Under FAR Part	Part 121
Flight Phase	cruise : level
Flight Plan	IFR
Person 1
Affiliation	government : faa
Function	controller : radar
Qualification	controller : radar
Experience	controller time certified in position1 : 15
ASRS Report	616153
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Events
Anomaly	altitude deviation : excursion from assigned altitude altitude deviation : undershoot conflict : airborne critical non adherence : published procedure
Independent Detector	atc equipment : conflict alert aircraft equipment : tcas
Resolutory Action	controller : issued new clearance controller : issued alert flight crew : took evasive action
Miss Distance	vertical : 1000
Supplementary
Problem Areas	ATC Human Performance
Primary Problem	ATC Human Performance

Narrative:

Aircraft X given clearance from FL280 to FL260. At 13 mi, they got an RA to climb back up. In this case, TCASII was very effective because the pilots were looking farther out than usual and separation was reestablished with vertical spacing before horizontal was lost.

Original NASA ASRS Text

Title: ZME CTLR DESCRIBES A NEAR LOSS OF SEPARATION SAVED BY TCASII AT FL270.

Narrative: ACFT X GIVEN CLRNC FROM FL280 TO FL260. AT 13 MI, THEY GOT AN RA TO CLB BACK UP. IN THIS CASE, TCASII WAS VERY EFFECTIVE BECAUSE THE PLTS WERE LOOKING FARTHER OUT THAN USUAL AND SEPARATION WAS REESTABLISHED WITH VERT SPACING BEFORE HORIZ WAS LOST.

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.