Flight crew responds to TCASII RA.

Attributes
ACN	319269
Time
Date	199510
Day	Wed
Local Time Of Day	0601 To 1200
Place
Locale Reference	airport : cmh
State Reference	OH
Altitude	msl bound lower : 6000 msl bound upper : 8000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	tracon : cmh
Operator	common carrier : air carrier
Make Model Name	MD-88
Operating Under FAR Part	Part 121
Navigation In Use	Other Other
Flight Phase	cruise other descent other
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : atp
Experience	flight time last 90 days : 180 flight time total : 5000 flight time type : 200
ASRS Report	319269
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Events
Anomaly	conflict : airborne less severe other anomaly other
Independent Detector	aircraft equipment other aircraft equipment : unspecified
Resolutory Action	flight crew : returned to intended course or assigned course flight crew : took evasive action
Consequence	faa : reviewed incident with flight crew
Miss Distance	horizontal : 7000 vertical : 100
Supplementary
Air Traffic Incident	other

Narrative:

Descending to cmh for runway 28L, cleared to 6000 ft (?). At about 8000 ft, ATC called traffic at 12 O'clock and 7 (?) mi. Traffic was on TCASII, but we couldn't see it visually. Traffic closed, we got 'traffic' (TA) from TCASII. Then controller issued turn left to 360 degree heading (about a 30 degree left turn). Captain reached up to rotate heading knob to 360 degrees but, before aircraft responded, we got an RA to 'descend.' I saw traffic at 12 O'clock on a collision course, so I took control, clicked off the autoplt, increased the descent rate and turned left. Maneuver was quick but not violent. Light twin passed about 1 to 1 1/2 mi right and about 100 ft high. After clear of traffic, I put aircraft back on autoplt and formally transferred control back to the captain. Captain was very mildly miffed at me for taking control, but I felt there was no time for discussion. This is a TCASII save, even with some help from ATC. I should have at least said 'tally-ho' or something to let him know I was maneuvering based on a visual. Evading (or responding to RA) using autoplt inputs would have been too slow in this case. I should have communicated better, but I would do the same thing again. Captain and I discussed coordination and control after we landed. No clearance deviation. TCASII is saving lives every day.

Original NASA ASRS Text

Title: FLC RESPONDS TO TCASII RA.

Narrative: DSNDING TO CMH FOR RWY 28L, CLRED TO 6000 FT (?). AT ABOUT 8000 FT, ATC CALLED TFC AT 12 O'CLOCK AND 7 (?) MI. TFC WAS ON TCASII, BUT WE COULDN'T SEE IT VISUALLY. TFC CLOSED, WE GOT 'TFC' (TA) FROM TCASII. THEN CTLR ISSUED TURN L TO 360 DEG HDG (ABOUT A 30 DEG L TURN). CAPT REACHED UP TO ROTATE HDG KNOB TO 360 DEGS BUT, BEFORE ACFT RESPONDED, WE GOT AN RA TO 'DSND.' I SAW TFC AT 12 O'CLOCK ON A COLLISION COURSE, SO I TOOK CTL, CLICKED OFF THE AUTOPLT, INCREASED THE DSCNT RATE AND TURNED L. MANEUVER WAS QUICK BUT NOT VIOLENT. LIGHT TWIN PASSED ABOUT 1 TO 1 1/2 MI R AND ABOUT 100 FT HIGH. AFTER CLR OF TFC, I PUT ACFT BACK ON AUTOPLT AND FORMALLY TRANSFERRED CTL BACK TO THE CAPT. CAPT WAS VERY MILDLY MIFFED AT ME FOR TAKING CTL, BUT I FELT THERE WAS NO TIME FOR DISCUSSION. THIS IS A TCASII SAVE, EVEN WITH SOME HELP FROM ATC. I SHOULD HAVE AT LEAST SAID 'TALLY-HO' OR SOMETHING TO LET HIM KNOW I WAS MANEUVERING BASED ON A VISUAL. EVADING (OR RESPONDING TO RA) USING AUTOPLT INPUTS WOULD HAVE BEEN TOO SLOW IN THIS CASE. I SHOULD HAVE COMMUNICATED BETTER, BUT I WOULD DO THE SAME THING AGAIN. CAPT AND I DISCUSSED COORD AND CTL AFTER WE LANDED. NO CLRNC DEV. TCASII IS SAVING LIVES EVERY DAY.

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.