Air carrier medium large transport altitude deviation excursion from clearance altitude in response ...

Attributes
ACN	197115
Time
Date	199112
Day	Sat
Local Time Of Day	1201 To 1800
Place
Locale Reference	atc facility : aus
State Reference	TX
Altitude	msl bound lower : 15000 msl bound upper : 15700
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zhu
Operator	common carrier : air carrier
Make Model Name	Medium Large Transport, Low Wing, 2 Turbojet Eng
Navigation In Use	Other
Flight Phase	cruise other descent other
Route In Use	arrival star : star enroute : on vectors enroute airway : zhu
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp pilot : flight engineer
Experience	flight time last 90 days : 192 flight time total : 15000 flight time type : 210
ASRS Report	197115
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : atp
Events
Anomaly	altitude deviation : excursion from assigned altitude conflict : airborne less severe
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:

First officer flying medium large transport on autoplt at 15000 ft, navigation on aus 083 degree radial prior to joining cugar STAR into iah. TCASII aural warning 'traffic, traffic,' looking in 1230 to 1 O'clock produced no visual target. Went to 5 mi scale (from 10). RA issued a climb and first officer disconnected autoplt and climbed to 15700 ft when TCASII issued a 'clear of conflict' message. Returned to 15000 and told controller we had an RA and climbed to 15700 ft. Frequency changed to iah approach and conducted a visual normal landing to runway 8. Intruder was never seen by cockpit crew nor was it pointed out by controller. 700 ft is what it took to resolve conflict. I don't know what vertical distance in reality we missed the intruder.

Original NASA ASRS Text

Title: ACR MLG ALTDEV EXCURSION FROM CLRNC ALT IN RESPONSE TO TCASII RA.

Narrative: FO FLYING MLG ON AUTOPLT AT 15000 FT, NAV ON AUS 083 DEG RADIAL PRIOR TO JOINING CUGAR STAR INTO IAH. TCASII AURAL WARNING 'TFC, TFC,' LOOKING IN 1230 TO 1 O'CLOCK PRODUCED NO VISUAL TARGET. WENT TO 5 MI SCALE (FROM 10). RA ISSUED A CLB AND FO DISCONNECTED AUTOPLT AND CLBED TO 15700 FT WHEN TCASII ISSUED A 'CLR OF CONFLICT' MESSAGE. RETURNED TO 15000 AND TOLD CTLR WE HAD AN RA AND CLBED TO 15700 FT. FREQ CHANGED TO IAH APCH AND CONDUCTED A VISUAL NORMAL LNDG TO RWY 8. INTRUDER WAS NEVER SEEN BY COCKPIT CREW NOR WAS IT POINTED OUT BY CTLR. 700 FT IS WHAT IT TOOK TO RESOLVE CONFLICT. I DON'T KNOW WHAT VERT DISTANCE IN REALITY WE MISSED THE INTRUDER.

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.

Air carrier medium large transport altitude deviation excursion from clearance altitude in response to TCASII RA.