Deviation from assigned altitude. Due to TCASII RA.

Attributes
ACN	202796
Time
Date	199202
Day	Tue
Local Time Of Day	0601 To 1200
Place
Locale Reference	atc facility : zla
State Reference	CA
Altitude	msl bound lower : 37000 msl bound upper : 37500
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zla
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 : on vectors enroute : direct enroute airway : zla
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : cfi pilot : flight engineer pilot : atp
Experience	flight time last 90 days : 200 flight time total : 11100 flight time type : 950
ASRS Report	202796
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	faa : reviewed incident with flight crew
Supplementary
Primary Problem	Aircraft
Air Traffic Incident	other

Narrative:

Level at FL370, we received TA on TCASII. Intruder was at 2 O'clock (on screen) at FL370. Several seconds later received 'climb-climb' RA. Climbed to FL37.5 and traffic intruder disappeared. Returned to assigned altitude. Never visually saw intruder. ATC seemed nonchalant and reported no aircraft at that altitude. This was a repeat airplane write-up (false alerts). Talking to other crews, and reading write-ups in other aircraft, false alerts are common near the colorado river due to military radar. If crews are taking evasive action for false targets, obviously there is a problem somewhere.

Original NASA ASRS Text

Title: DEV FROM ASSIGNED ALT. DUE TO TCASII RA.

Narrative: LEVEL AT FL370, WE RECEIVED TA ON TCASII. INTRUDER WAS AT 2 O'CLOCK (ON SCREEN) AT FL370. SEVERAL SECONDS LATER RECEIVED 'CLB-CLB' RA. CLBED TO FL37.5 AND TFC INTRUDER DISAPPEARED. RETURNED TO ASSIGNED ALT. NEVER VISUALLY SAW INTRUDER. ATC SEEMED NONCHALANT AND RPTED NO ACFT AT THAT ALT. THIS WAS A REPEAT AIRPLANE WRITE-UP (FALSE ALERTS). TALKING TO OTHER CREWS, AND READING WRITE-UPS IN OTHER ACFT, FALSE ALERTS ARE COMMON NEAR THE COLORADO RIVER DUE TO MIL RADAR. IF CREWS ARE TAKING EVASIVE ACTION FOR FALSE TARGETS, OBVIOUSLY THERE IS A PROBLEM SOMEWHERE.

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.