TCASII RA creates an altitude deviation altitude excursion by PIC.

Attributes
ACN	188607
Time
Date	199108
Day	Thu
Local Time Of Day	1201 To 1800
Place
Locale Reference	atc facility : pxt
State Reference	MD
Altitude	msl bound lower : 25300 msl bound upper : 26000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zdc
Operator	common carrier : air carrier
Make Model Name	Widebody, Low Wing, 3 Turbojet Eng
Flight Phase	cruise other
Flight Plan	IFR
Aircraft 2
Operator	common carrier : air carrier
Make Model Name	Medium Large Transport, Low Wing, 2 Turbojet Eng
Flight Phase	descent other
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : atp
ASRS Report	188607
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Events
Anomaly	altitude deviation : excursion from assigned altitude non adherence : clearance other anomaly other
Independent Detector	aircraft equipment other aircraft equipment : unspecified
Resolutory Action	flight crew : took evasive action
Consequence	faa : reviewed incident with flight crew
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation other

Narrative:

Near pxt (patuxent) VOR at FL260, received a TCASII TA and observed on scope target 10 NM ahead, opposite direction, 2400 ft above and descending. At 7 NM the TA turned to an RA which commanded captain to descend at 2000 FPM on vertical speed indicator. Conflict aircraft was now 2000 ft above, descending, and closing. At 25500 ft MSL the RA stopped. The captain stopped descent at 25300 ft and began climb back to FL260. Start of descent from FL260 was reported to ATC 'due to RA', washington center. They reported conflicting traffic had been cleared to FL270 where he leveled and presented no threat.

Original NASA ASRS Text

Title: TCASII RA CREATES AN ALT DEV ALT EXCURSION BY PIC.

Narrative: NEAR PXT (PATUXENT) VOR AT FL260, RECEIVED A TCASII TA AND OBSERVED ON SCOPE TARGET 10 NM AHEAD, OPPOSITE DIRECTION, 2400 FT ABOVE AND DSNDING. AT 7 NM THE TA TURNED TO AN RA WHICH COMMANDED CAPT TO DSND AT 2000 FPM ON VERT SPD INDICATOR. CONFLICT ACFT WAS NOW 2000 FT ABOVE, DSNDING, AND CLOSING. AT 25500 FT MSL THE RA STOPPED. THE CAPT STOPPED DSCNT AT 25300 FT AND BEGAN CLB BACK TO FL260. START OF DSCNT FROM FL260 WAS RPTED TO ATC 'DUE TO RA', WASHINGTON CENTER. THEY RPTED CONFLICTING TFC HAD BEEN CLRED TO FL270 WHERE HE LEVELED AND PRESENTED NO THREAT.

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.