Air carrier climbs above assigned altitude when distraction by TCASII RA.

Attributes
ACN	197000
Time
Date	199112
Day	Wed
Local Time Of Day	1201 To 1800
Place
Locale Reference	atc facility : dfw
State Reference	TX
Altitude	msl bound lower : 27000 msl bound upper : 27300
Environment
Flight Conditions	IMC
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zfw
Operator	common carrier : air carrier
Make Model Name	Large Transport, Low Wing, 3 Turbojet Eng
Flight Phase	climbout : intermediate altitude
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : flight engineer pilot : commercial
Experience	flight time last 90 days : 150 flight time total : 3200 flight time type : 2000
ASRS Report	197000
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Experience	flight time last 90 days : 160 flight time total : 8000
ASRS Report	196839
Events
Anomaly	altitude deviation : overshoot non adherence : clearance other anomaly other
Independent Detector	other controllera other flight crewa
Resolutory Action	none taken : anomaly accepted
Consequence	Other
Miss Distance	vertical : 800
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation other

Narrative:

While climbing through FL260 ftw center informed us to level at FL270 in 1 min or less for traffic. At FL269 while leveling for FL270 the captain inquired the copilot about a traffic proximity symbol approaching from 11 O'clock. ATC issued a traffic report, however the altitude portion of the report was blocked by the TCASII audio warning 'traffic, traffic.' while leveling at FL270 we received a RA warning. Focus shifted from the altimeter to the ivsi to execute the RA command. Interpretation was delayed by the knowledge of traffic below, a delay in the appearance of the ivsi's advisory lights, the suns washout affect of the ivsi lights when they did appear, and the RA's relative altitude separation of 09+ when we were 100 ft low of assigned altitude. We continued our current steady state flight conditions (slight climb) during interpretation, then followed the TCASII level command. The aircraft ballooned above the assigned altitude during the maneuver. ATC inquired about our altitude after we made the necessary correction. Supplemental information from acn 197104. Interpretation was delayed by the knowledge of traffic below and what seemed to be a delay in the ivsi TCASII lights appearing. The TCASII command was followed. At the same time, I spotted the other aircraft visually, and determined he was not a hazard.

Original NASA ASRS Text

Title: ACR CLBS ABOVE ASSIGNED ALT WHEN DISTR BY TCASII RA.

Narrative: WHILE CLBING THROUGH FL260 FTW CENTER INFORMED US TO LEVEL AT FL270 IN 1 MIN OR LESS FOR TFC. AT FL269 WHILE LEVELING FOR FL270 THE CAPT INQUIRED THE COPLT ABOUT A TFC PROX SYMBOL APCHING FROM 11 O'CLOCK. ATC ISSUED A TFC RPT, HOWEVER THE ALT PORTION OF THE RPT WAS BLOCKED BY THE TCASII AUDIO WARNING 'TFC, TFC.' WHILE LEVELING AT FL270 WE RECEIVED A RA WARNING. FOCUS SHIFTED FROM THE ALTIMETER TO THE IVSI TO EXECUTE THE RA COMMAND. INTERPRETATION WAS DELAYED BY THE KNOWLEDGE OF TFC BELOW, A DELAY IN THE APPEARANCE OF THE IVSI'S ADVISORY LIGHTS, THE SUNS WASHOUT AFFECT OF THE IVSI LIGHTS WHEN THEY DID APPEAR, AND THE RA'S RELATIVE ALT SEPARATION OF 09+ WHEN WE WERE 100 FT LOW OF ASSIGNED ALT. WE CONTINUED OUR CURRENT STEADY STATE FLT CONDITIONS (SLIGHT CLB) DURING INTERPRETATION, THEN FOLLOWED THE TCASII LEVEL COMMAND. THE ACFT BALLOONED ABOVE THE ASSIGNED ALT DURING THE MANEUVER. ATC INQUIRED ABOUT OUR ALT AFTER WE MADE THE NECESSARY CORRECTION. SUPPLEMENTAL INFO FROM ACN 197104. INTERPRETATION WAS DELAYED BY THE KNOWLEDGE OF TFC BELOW AND WHAT SEEMED TO BE A DELAY IN THE IVSI TCASII LIGHTS APPEARING. THE TCASII COMMAND WAS FOLLOWED. AT THE SAME TIME, I SPOTTED THE OTHER ACFT VISUALLY, AND DETERMINED HE WAS NOT A HAZARD.

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.