Large transport has TCASII RA. Climbs, determines it is false warning.

Attributes
ACN	235990
Time
Date	199303
Day	Mon
Local Time Of Day	1201 To 1800
Place
Locale Reference	airport : ord
State Reference	IL
Altitude	msl bound lower : 4500 msl bound upper : 5300
Environment
Flight Conditions	Mixed
Light	Dusk
Aircraft 1
Controlling Facilities	tracon : ord artcc : zny
Operator	common carrier : air carrier
Make Model Name	Large Transport, Low Wing, 2 Turbojet Eng
Navigation In Use	Other Other
Flight Phase	climbout : initial
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp pilot : flight engineer
Experience	flight time last 90 days : 180 flight time total : 10000 flight time type : 700
ASRS Report	235990
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : atp pilot : instrument pilot : commercial
Events
Anomaly	altitude deviation : overshoot 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 flight crew : took evasive action other
Consequence	Other
Supplementary
Primary Problem	Aircraft
Air Traffic Incident	other

Narrative:

At 4500 ft got a TCASII to monitor rate at 4800 ft to increase rate. We were cleared to 5000 ft. Went to 5300 ft, told controller, he said no traffic and do what we had to. Traffic symbol was 100 ft below us and climbing in formation with us. At 5300 ft I decided it was a false warning and stopped climb. Controller cleared us to 6000 ft. I talked to chief pilot at ord and he said that the military uses aircraft to adjust their radar and it's a problem around navy glenview.

Original NASA ASRS Text

Title: LGT HAS TCASII RA. CLBS, DETERMINES IT IS FALSE WARNING.

Narrative: AT 4500 FT GOT A TCASII TO MONITOR RATE AT 4800 FT TO INCREASE RATE. WE WERE CLRED TO 5000 FT. WENT TO 5300 FT, TOLD CTLR, HE SAID NO TFC AND DO WHAT WE HAD TO. TFC SYMBOL WAS 100 FT BELOW US AND CLBING IN FORMATION WITH US. AT 5300 FT I DECIDED IT WAS A FALSE WARNING AND STOPPED CLB. CTLR CLRED US TO 6000 FT. I TALKED TO CHIEF PLT AT ORD AND HE SAID THAT THE MIL USES ACFT TO ADJUST THEIR RADAR AND IT'S A PROB AROUND NAVY GLENVIEW.

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.