Altitude deviation due to TCASII.

Attributes
ACN	278723
Time
Date	199407
Day	Mon
Local Time Of Day	1201 To 1800
Place
Locale Reference	atc facility : pie
State Reference	FL
Altitude	msl bound lower : 12500 msl bound upper : 13000
Environment
Flight Conditions	Mixed
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zid
Operator	common carrier : air carrier
Make Model Name	Commercial Fixed Wing
Operating Under FAR Part	Part 121
Flight Phase	climbout : intermediate altitude
Route In Use	departure other enroute airway : zma
Flight Plan	IFR
Aircraft 2
Make Model Name	Any Unknown or Unlisted Aircraft Manufacturer
Operating Under FAR Part	other : unknown
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp pilot : flight engineer pilot : commercial pilot : cfi pilot : instrument
Experience	flight time last 90 days : 150 flight time total : 10000 flight time type : 3000
ASRS Report	278723
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : instrument pilot : commercial
Events
Anomaly	aircraft equipment problem : less severe altitude deviation : excursion from assigned altitude non adherence : clearance non adherence : required legal separation other anomaly other
Independent Detector	aircraft equipment other aircraft equipment : unspecified other flight crewa
Resolutory Action	none taken : anomaly accepted
Consequence	faa : reviewed incident with flight crew
Supplementary
Primary Problem	Aircraft
Air Traffic Incident	Pilot Deviation other

Narrative:

Approaching 13000 ft MSL during climb out, we had a TCASII TA pop upon the screen at 12 O'clock and less than 5 mi. Simultaneously, almost, the controller advised us of traffic at 12 O'clock and 2 mi at 13300 ft. We could not see the traffic due to the WX conditions. Also, although we did not receive a RA, because of the close proximity of the traffic (2 mi and 300 ft) and our rate of climb and closure rate, I elected to stop the climb and initiated a brief descent (down to approximately 12500 ft MSL) until we cleared the traffic. I advised the controller of my actions and reasons. She mentioned some traffic below us and we immediately resumed our climb to altitude. Previous TCASII events I have experienced worked just as they were supposed to, but this one was unconventional. The traffic should have appeared sooner on our screen the way we had it configured (30 mi scale and above) and, with the controller confirming the position and altitude of the traffic, we felt we had a potential problem and acted to resolve it using our best judgement and experience.

Original NASA ASRS Text

Title: ALTDEV DUE TO TCASII.

Narrative: APCHING 13000 FT MSL DURING CLBOUT, WE HAD A TCASII TA POP UPON THE SCREEN AT 12 O'CLOCK AND LESS THAN 5 MI. SIMULTANEOUSLY, ALMOST, THE CTLR ADVISED US OF TFC AT 12 O'CLOCK AND 2 MI AT 13300 FT. WE COULD NOT SEE THE TFC DUE TO THE WX CONDITIONS. ALSO, ALTHOUGH WE DID NOT RECEIVE A RA, BECAUSE OF THE CLOSE PROX OF THE TFC (2 MI AND 300 FT) AND OUR RATE OF CLB AND CLOSURE RATE, I ELECTED TO STOP THE CLB AND INITIATED A BRIEF DSCNT (DOWN TO APPROX 12500 FT MSL) UNTIL WE CLRED THE TFC. I ADVISED THE CTLR OF MY ACTIONS AND REASONS. SHE MENTIONED SOME TFC BELOW US AND WE IMMEDIATELY RESUMED OUR CLB TO ALT. PREVIOUS TCASII EVENTS I HAVE EXPERIENCED WORKED JUST AS THEY WERE SUPPOSED TO, BUT THIS ONE WAS UNCONVENTIONAL. THE TFC SHOULD HAVE APPEARED SOONER ON OUR SCREEN THE WAY WE HAD IT CONFIGURED (30 MI SCALE AND ABOVE) AND, WITH THE CTLR CONFIRMING THE POS AND ALT OF THE TFC, WE FELT WE HAD A POTENTIAL PROB AND ACTED TO RESOLVE IT USING OUR BEST JUDGEMENT AND EXPERIENCE.

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.