Altitude deviation altitude undershot altitude excursion in pilot response to TCASII RA.

Attributes
ACN	214180
Time
Date	199206
Day	Sun
Local Time Of Day	1201 To 1800
Place
Locale Reference	airport : rdu
State Reference	NC
Altitude	msl bound lower : 5000 msl bound upper : 5400
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	tracon : rdu
Operator	common carrier : air carrier
Make Model Name	Light Transport, High Wing, 2 Turboprop Eng
Flight Phase	descent other
Route In Use	arrival other arrival star : star enroute : direct
Flight Plan	IFR
Aircraft 2
Make Model Name	Any Unknown or Unlisted Aircraft Manufacturer
Flight Phase	cruise other
Route In Use	enroute : direct
Flight Plan	VFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : cfi pilot : atp
Experience	flight time last 90 days : 90 flight time total : 2450 flight time type : 100
ASRS Report	214180
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : commercial pilot : instrument
Events
Anomaly	altitude deviation : undershoot conflict : airborne less severe non adherence : clearance
Independent Detector	aircraft equipment other aircraft equipment : unspecified
Resolutory Action	flight crew : took evasive action
Consequence	faa : reviewed incident with flight crew
Miss Distance	horizontal : 12000 vertical : 400
Supplementary
Primary Problem	Aircraft
Air Traffic Incident	Pilot Deviation other

Narrative:

As we were cleared to descend from 6000 to 4000, we encountered a RA on our TCASII system as we passed through 5000 ft. We initiated a climb, as per the vsi arc and TCASII. I advised raleigh approach control of our deviation and was told to contact the facility when we landed. There was no incident or accident to be reported, however approach told me that they needed to file a report regardless of the outcome. I feel that the TCASII system did provide a reasonable course of action to avoid a conflict and that airborne avoidance systems only enhance the ATC system.

Original NASA ASRS Text

Title: ALTDEV ALT UNDERSHOT ALT EXCURSION IN PLT RESPONSE TO TCASII RA.

Narrative: AS WE WERE CLRED TO DSND FROM 6000 TO 4000, WE ENCOUNTERED A RA ON OUR TCASII SYS AS WE PASSED THROUGH 5000 FT. WE INITIATED A CLB, AS PER THE VSI ARC AND TCASII. I ADVISED RALEIGH APCH CTL OF OUR DEV AND WAS TOLD TO CONTACT THE FACILITY WHEN WE LANDED. THERE WAS NO INCIDENT OR ACCIDENT TO BE RPTED, HOWEVER APCH TOLD ME THAT THEY NEEDED TO FILE A RPT REGARDLESS OF THE OUTCOME. I FEEL THAT THE TCASII SYS DID PROVIDE A REASONABLE COURSE OF ACTION TO AVOID A CONFLICT AND THAT AIRBORNE AVOIDANCE SYSTEMS ONLY ENHANCE THE ATC SYS.

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.