Altitude deviation altitude excursion after TCASII RA on opposite direction traffic.

Attributes
ACN	201626
Time
Date	199202
Day	Thu
Local Time Of Day	0601 To 1200
Place
Locale Reference	atc facility : okk
State Reference	IN
Altitude	msl bound lower : 27000 msl bound upper : 27300
Environment
Flight Conditions	Mixed
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zau
Operator	common carrier : air carrier
Make Model Name	Medium Large Transport, Low Wing, 2 Turbojet Eng
Navigation In Use	Other Other
Flight Phase	cruise other
Route In Use	enroute : on vectors enroute : direct
Flight Plan	IFR
Aircraft 2
Operator	common carrier : air carrier
Make Model Name	Any Unknown or Unlisted Aircraft Manufacturer
Flight Phase	climbout : intermediate altitude
Route In Use	enroute : on vectors
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Experience	flight time last 90 days : 180 flight time total : 11000 flight time type : 1000
ASRS Report	201626
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : atp
Events
Anomaly	aircraft equipment problem : less severe altitude deviation : excursion from assigned altitude non adherence : clearance other anomaly other
Independent Detector	aircraft equipment other aircraft equipment : unspecified
Resolutory Action	flight crew : exited adverse environment flight crew : took evasive action
Consequence	faa : reviewed incident with flight crew
Miss Distance	vertical : 1000
Supplementary
Primary Problem	Aircraft
Air Traffic Incident	Pilot Deviation

Narrative:

Position approximately 35 mi sse okk VOR proceeding direct okk VOR level FL270. TCASII in TA/RA mode. TCASII traffic observed 12-1 O'clock. Traffic also pointed out by ATC. Traffic was climbing through 250. Events then occurred quickly. TCASII gave TA followed by RA to climb. On my order first officer started to climb. I then informed ATC of our actions due to TCASII RA. ATC began explaining that no traffic conflict existed. My assessment was that this was probably correct but I was not 100 percent convinced and still elected to climb. ATC then issued a 270 degree vector (from 330 degrees). At the same instant TCASII sounded clear of traffic. We informed ATC of this and received direct okk. Opposite traffic said it received a TCASII TA but no RA. ATC said we were not in a situation that required us to take the action. We took the action because of what appeared to be a valid TCASII RA.

Original NASA ASRS Text

Title: ALTDEV ALT EXCURSION AFTER TCASII RA ON OPPOSITE DIRECTION TFC.

Narrative: POS APPROX 35 MI SSE OKK VOR PROCEEDING DIRECT OKK VOR LEVEL FL270. TCASII IN TA/RA MODE. TCASII TFC OBSERVED 12-1 O'CLOCK. TFC ALSO POINTED OUT BY ATC. TFC WAS CLBING THROUGH 250. EVENTS THEN OCCURRED QUICKLY. TCASII GAVE TA FOLLOWED BY RA TO CLB. ON MY ORDER FO STARTED TO CLB. I THEN INFORMED ATC OF OUR ACTIONS DUE TO TCASII RA. ATC BEGAN EXPLAINING THAT NO TFC CONFLICT EXISTED. MY ASSESSMENT WAS THAT THIS WAS PROBABLY CORRECT BUT I WAS NOT 100 PERCENT CONVINCED AND STILL ELECTED TO CLB. ATC THEN ISSUED A 270 DEG VECTOR (FROM 330 DEGS). AT THE SAME INSTANT TCASII SOUNDED CLR OF TFC. WE INFORMED ATC OF THIS AND RECEIVED DIRECT OKK. OPPOSITE TFC SAID IT RECEIVED A TCASII TA BUT NO RA. ATC SAID WE WERE NOT IN A SITUATION THAT REQUIRED US TO TAKE THE ACTION. WE TOOK THE ACTION BECAUSE OF WHAT APPEARED TO BE A VALID TCASII RA.

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.