Air carrier flight crew deviated from their assigned altitude in response to the aircraft's TCASII a...

Attributes
ACN	205092
Time
Date	199203
Day	Sat
Local Time Of Day	0601 To 1200
Place
Locale Reference	atc facility : tcc
State Reference	NM
Altitude	msl bound lower : 25200 msl bound upper : 26000
Environment
Flight Conditions	Mixed
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zab
Operator	common carrier : air carrier
Make Model Name	Large Transport, Low Wing, 2 Turbojet Eng
Navigation In Use	Other Other
Flight Phase	cruise other
Route In Use	enroute airway : zab
Flight Plan	IFR
Aircraft 2
Make Model Name	Any Unknown or Unlisted Aircraft Manufacturer
Flight Phase	cruise other
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : instrument pilot : commercial pilot : flight engineer
Experience	flight time last 90 days : 180 flight time total : 4000 flight time type : 2000
ASRS Report	205092
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 other flight crewa
Resolutory Action	flight crew : returned to intended course or assigned course
Consequence	Other
Miss Distance	horizontal : 18000 vertical : 1000
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

TCASII issued an RA to descend. We descended to FL252 and informed the controller. Traffic was spotted about 30 seconds later at our 3 O'clock at 3 mi and 1000 ft above us. After clearing, we climbed to FL260. It appeared the TCASII was too sensitive and should not have issued the RA.

Original NASA ASRS Text

Title: ACR FLC DEVIATED FROM THEIR ASSIGNED ALT IN RESPONSE TO THE ACFT'S TCASII ALERT WARNING.

Narrative: TCASII ISSUED AN RA TO DSND. WE DSNDED TO FL252 AND INFORMED THE CTLR. TFC WAS SPOTTED ABOUT 30 SECONDS LATER AT OUR 3 O'CLOCK AT 3 MI AND 1000 FT ABOVE US. AFTER CLRING, WE CLBED TO FL260. IT APPEARED THE TCASII WAS TOO SENSITIVE AND SHOULD NOT HAVE ISSUED THE RA.

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.

Air carrier flight crew deviated from their assigned altitude in response to the aircraft's TCASII alert warning.