Computer aircraft receives TCASII RA in IMC. Responds.

Attributes
ACN	222282
Time
Date	199209
Day	Sun
Local Time Of Day	1201 To 1800
Place
Locale Reference	airport : clt
State Reference	NC
Altitude	msl bound lower : 8500 msl bound upper : 9000
Environment
Flight Conditions	IMC
Light	Daylight
Aircraft 1
Controlling Facilities	tracon : clt
Operator	common carrier : air carrier
Make Model Name	Medium Transport, High Wing, 2 Turboprop Eng
Navigation In Use	Other
Flight Phase	cruise other descent : approach descent other
Route In Use	arrival other
Flight Plan	IFR
Aircraft 2
Operator	common carrier : air carrier
Make Model Name	Any Unknown or Unlisted Aircraft Manufacturer
Flight Phase	descent other
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Experience	flight time last 90 days : 270 flight time total : 7000 flight time type : 3000
ASRS Report	222282
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : instrument pilot : commercial
Events
Anomaly	altitude deviation : excursion from assigned altitude conflict : airborne less severe non adherence : clearance other anomaly other
Independent Detector	aircraft equipment other aircraft equipment : unspecified
Resolutory Action	flight crew : took evasive action
Consequence	Other
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	other

Narrative:

Cruising at 9000 ft under control of clt approach frequency 126.15, we received a TA from ATC that an medium large transport was coming up on us 6 O'clock descending to 10000 ft. When the medium large transport passed 2400 ft above us, the TCASII issued a TA, followed by an RA 'descend, descend now,' when the medium large transport passed 1400 ft above us. We left 9000 ft to comply with the RA with a descent rate of 1000 to 2000 FPM until reading 8500 ft when the RA eased without verbal warning. (Only red arc on the top half of the ivsi). When the RA totally cleared, we returned back to 9000 ft. At 9000 ft we noticed the medium large transport above us at 900 ft according to the TCASII. While complying with the TCASII RA we notified ATC of the RA compliance.

Original NASA ASRS Text

Title: COMPUTER ACFT RECEIVES TCASII RA IN IMC. RESPONDS.

Narrative: CRUISING AT 9000 FT UNDER CTL OF CLT APCH FREQ 126.15, WE RECEIVED A TA FROM ATC THAT AN MLG WAS COMING UP ON US 6 O'CLOCK DSNDING TO 10000 FT. WHEN THE MLG PASSED 2400 FT ABOVE US, THE TCASII ISSUED A TA, FOLLOWED BY AN RA 'DSND, DSND NOW,' WHEN THE MLG PASSED 1400 FT ABOVE US. WE LEFT 9000 FT TO COMPLY WITH THE RA WITH A DSCNT RATE OF 1000 TO 2000 FPM UNTIL READING 8500 FT WHEN THE RA EASED WITHOUT VERBAL WARNING. (ONLY RED ARC ON THE TOP HALF OF THE IVSI). WHEN THE RA TOTALLY CLRED, WE RETURNED BACK TO 9000 FT. AT 9000 FT WE NOTICED THE MLG ABOVE US AT 900 FT ACCORDING TO THE TCASII. WHILE COMPLYING WITH THE TCASII RA WE NOTIFIED ATC OF THE RA COMPLIANCE.

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.