Altitude deviation account TCASII RA.

Attributes
ACN	176048
Time
Date	199104
Day	Fri
Local Time Of Day	0601 To 1200
Place
Locale Reference	atc facility : vhp
State Reference	IN
Altitude	msl bound lower : 34500 msl bound upper : 35000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zid
Operator	common carrier : air carrier
Make Model Name	Widebody, Low Wing, 3 Turbojet Eng
Navigation In Use	Other
Flight Phase	cruise other
Route In Use	enroute airway : j80
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Experience	flight time last 90 days : 120 flight time total : 14000 flight time type : 5000
ASRS Report	176048
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : commercial pilot : instrument
Events
Anomaly	aircraft equipment problem : less severe altitude deviation : excursion from assigned altitude
Independent Detector	aircraft equipment other aircraft equipment : unspecified
Resolutory Action	flight crew : returned to intended course or assigned course
Consequence	Other
Supplementary
Primary Problem	Aircraft
Air Traffic Incident	other

Narrative:

A sudden TCAS RA warning command (visibility and aural) occurred at above time and place. An immediate descent was started and I advised ATC. Descended 500' to FL345 before level-off. ATC advised us that no traffic was anywhere near us so we climbed back to FL350. After return to FL350, first officer told me that RA did not come on his side; the false RA was only on the captain's side. RA warning was complete (symbol on WX screen, vertical speed indicator). Aural was, 'traffic, traffic. Descend, descend.' callback conversation with reporter revealed the following: reporter filed a report with company, but has received no information to date. First officer, PF, was confused by the warning since his unit did not indicate an RA. The descent was delayed. In general, the reporter likes the equipment, but his airline has put it on hold until a new software system can be installed. Does not like the noise level and has received some false warnings shortly after takeoff. Would like to see some warnings inhibited until the flaps are retracted and then the system activated. Company policy is to use the TA function only until the after takeoff check is complete, but sometimes this can be delayed till nearing 10000'.

Original NASA ASRS Text

Title: ALT DEVIATION ACCOUNT TCASII RA.

Narrative: A SUDDEN TCAS RA WARNING COMMAND (VIS AND AURAL) OCCURRED AT ABOVE TIME AND PLACE. AN IMMEDIATE DSNT WAS STARTED AND I ADVISED ATC. DSNDED 500' TO FL345 BEFORE LEVEL-OFF. ATC ADVISED US THAT NO TFC WAS ANYWHERE NEAR US SO WE CLBED BACK TO FL350. AFTER RETURN TO FL350, F/O TOLD ME THAT RA DID NOT COME ON HIS SIDE; THE FALSE RA WAS ONLY ON THE CAPT'S SIDE. RA WARNING WAS COMPLETE (SYMBOL ON WX SCREEN, VERT SPD INDICATOR). AURAL WAS, 'TFC, TFC. DSND, DSND.' CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING: RPTR FILED A RPT WITH COMPANY, BUT HAS RECEIVED NO INFO TO DATE. F/O, PF, WAS CONFUSED BY THE WARNING SINCE HIS UNIT DID NOT INDICATE AN RA. THE DSNT WAS DELAYED. IN GENERAL, THE RPTR LIKES THE EQUIP, BUT HIS AIRLINE HAS PUT IT ON HOLD UNTIL A NEW SOFTWARE SYS CAN BE INSTALLED. DOES NOT LIKE THE NOISE LEVEL AND HAS RECEIVED SOME FALSE WARNINGS SHORTLY AFTER TKOF. WOULD LIKE TO SEE SOME WARNINGS INHIBITED UNTIL THE FLAPS ARE RETRACTED AND THEN THE SYS ACTIVATED. COMPANY POLICY IS TO USE THE TA FUNCTION ONLY UNTIL THE AFTER TKOF CHK IS COMPLETE, BUT SOMETIMES THIS CAN BE DELAYED TILL NEARING 10000'.

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.