EMB135 flight crew descended in response to a TCASII RA and stopped descent when approaching high rising mountainous terrain and observing no conflicting traffic or non observed by the departure controller.

Home

Browse by month

Random

Latest

About

Contact

Attributes
ACN	512018
Time
Date	200105
Day	Mon
Local Time Of Day	0601 To 1200
Place
Locale Reference	navaid : vxv.vortac
State Reference	TN
Altitude	msl bound lower : 7800 msl bound upper : 9000
Environment
Flight Conditions	IMC
Light	Daylight
Aircraft 1
Controlling Facilities	tracon : tys.tracon tracon : d21.tracon
Operator	common carrier : air carrier
Make Model Name	EMB ERJ 135 ER&LR
Operating Under FAR Part	Part 121
Navigation In Use	other
Flight Phase	climbout : intermediate altitude
Route In Use	departure : on vectors
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : atp
Experience	flight time last 90 days : 160 flight time total : 29000 flight time type : 200
ASRS Report	512018
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Events
Anomaly	aircraft equipment problem : critical altitude deviation : excursion from assigned altitude non adherence : published procedure non adherence : clearance
Independent Detector	aircraft equipment : tcas other flight crewa
Resolutory Action	flight crew : took precautionary avoidance action flight crew : overrode automation
Consequence	faa : reviewed incident with flight crew other
Supplementary
Problem Areas	Aircraft
Primary Problem	Aircraft

Narrative:

Upon climb out from tys, en route to cle, we received an RA from our TCASII. The initial RA was received at approximately 9000 ft, at which time we immediately began a descent as instructed to do by the TCASII. At the same time, I notified ATC of the possible conflict and advised them that we were descending as per the RA. At approximately 7800 ft, we began to stop our descent. Since TCASII was still advising us to descend at 1500 FPM and after verifying twice with ATC that there was no conflicting traffic on his radar, we (crew) determined that it was the TCASII which was giving us a false RA. Positional awareness. Was critical in this incident, since we were in mountainous terrain and if we would have continued a descent as per RA, we would have contacted the terrain at approximately 5600 ft MSL. The TCASII system was turned off and we continued to the destination without further incident. The inoperative TCASII system was noted in the aircraft logbook and the proper MEL was placed upon it by maintenance control.

Original NASA ASRS Text

Title: EMB135 FLC DSNDED IN RESPONSE TO A TCASII RA AND STOPPED DSCNT WHEN APCHING HIGH RISING MOUNTAINOUS TERRAIN AND OBSERVING NO CONFLICTING TFC OR NON OBSERVED BY THE DEP CTLR.

Narrative: UPON CLBOUT FROM TYS, ENRTE TO CLE, WE RECEIVED AN RA FROM OUR TCASII. THE INITIAL RA WAS RECEIVED AT APPROX 9000 FT, AT WHICH TIME WE IMMEDIATELY BEGAN A DSCNT AS INSTRUCTED TO DO BY THE TCASII. AT THE SAME TIME, I NOTIFIED ATC OF THE POSSIBLE CONFLICT AND ADVISED THEM THAT WE WERE DSNDING AS PER THE RA. AT APPROX 7800 FT, WE BEGAN TO STOP OUR DSCNT. SINCE TCASII WAS STILL ADVISING US TO DSND AT 1500 FPM AND AFTER VERIFYING TWICE WITH ATC THAT THERE WAS NO CONFLICTING TFC ON HIS RADAR, WE (CREW) DETERMINED THAT IT WAS THE TCASII WHICH WAS GIVING US A FALSE RA. POSITIONAL AWARENESS. WAS CRITICAL IN THIS INCIDENT, SINCE WE WERE IN MOUNTAINOUS TERRAIN AND IF WE WOULD HAVE CONTINUED A DSCNT AS PER RA, WE WOULD HAVE CONTACTED THE TERRAIN AT APPROX 5600 FT MSL. THE TCASII SYS WAS TURNED OFF AND WE CONTINUED TO THE DEST WITHOUT FURTHER INCIDENT. THE INOP TCASII SYS WAS NOTED IN THE ACFT LOGBOOK AND THE PROPER MEL WAS PLACED UPON IT BY MAINT CTL.

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.