Attempting to follow approach controllers instructions, flight crew of medium large transport was di...

Attributes
ACN	196984
Time
Date	199112
Day	Sun
Local Time Of Day	0601 To 1200
Place
Locale Reference	airport : sna
State Reference	CA
Altitude	msl bound lower : 3000 msl bound upper : 7000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	tracon : sna
Operator	common carrier : air carrier
Make Model Name	Medium Large Transport, Low Wing, 2 Turbojet Eng
Flight Phase	descent : approach descent other
Route In Use	approach : visual
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp pilot : instrument pilot : commercial
Experience	flight time last 90 days : 250 flight time total : 15000 flight time type : 6000
ASRS Report	196984
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : commercial pilot : instrument pilot : atp
Events
Anomaly	altitude deviation : excursion from assigned altitude non adherence : clearance other anomaly other other spatial deviation
Independent Detector	aircraft equipment other aircraft equipment : unspecified other flight crewa
Resolutory Action	none taken : anomaly accepted
Consequence	Other
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

Inbound to sna on kayoh 2 arrival, coast approach advised us we would be vectored across 19R localizer for spacing, for a visual approach. This being a sunday with large numbers of light aircraft, this was later to expose us to a number of conflicting traffic. We ended up being turned north just east of anaheim as lower altitudes to descend to (from 7000 MSL to 3000 MSL). Approach also pointed out several aircraft as traffic. TCASII gave us several traffic alert messages (TA) as well as 3 resolutions advisories (RA). 2 ras commanded dscnts, which we were able to follow, merely by increasing rate to resolve conflict, and still be above altitude descending to. The third commanded a climb (still descending), which was initiated, and after gaining a couple of hundred ft at most, we were clear of conflict. In each case we saw traffic after gaining a couple of hundred ft at most. We were clear of conflict. In each case we saw traffic after getting RA message. Each message gave correct RA. This approach was made extremely busy and difficult, to where our ability to receive and follow ATC instructions were compromised. The controller was advised of this, after we missed what he said while the controller and TCASII computer (audio) were talking at the same time. This happened more than once, significantly increasing the workload for all of us. According to controller, we missed a heading change, and were not aware of this until he questioned our lack of response. The only reason we were able to follow RA commands, was by visual picture on ivsi, as constant chatter garbled audio message. TCASII does not presently fit into ATC system, but adds an element of interruption and confusion to an already overloaded system. Nor does it fit into our present cockpit management, preventing pilots from making timely verbal commands and also their ability to understand same.

Original NASA ASRS Text

Title: ATTEMPTING TO FOLLOW APCH CTLRS INSTRUCTIONS, FLC OF MLG WAS DISTR BY OVER LOUD TCASII ALERTS AND UNABLE TO HEAR CTLR INSTRUCTIONS. MISSING A HDG CHANGE.

Narrative: INBOUND TO SNA ON KAYOH 2 ARR, COAST APCH ADVISED US WE WOULD BE VECTORED ACROSS 19R LOC FOR SPACING, FOR A VISUAL APCH. THIS BEING A SUNDAY WITH LARGE NUMBERS OF LIGHT ACFT, THIS WAS LATER TO EXPOSE US TO A NUMBER OF CONFLICTING TFC. WE ENDED UP BEING TURNED N JUST E OF ANAHEIM AS LOWER ALTS TO DSND TO (FROM 7000 MSL TO 3000 MSL). APCH ALSO POINTED OUT SEVERAL ACFT AS TFC. TCASII GAVE US SEVERAL TFC ALERT MESSAGES (TA) AS WELL AS 3 RESOLUTIONS ADVISORIES (RA). 2 RAS COMMANDED DSCNTS, WHICH WE WERE ABLE TO FOLLOW, MERELY BY INCREASING RATE TO RESOLVE CONFLICT, AND STILL BE ABOVE ALT DSNDING TO. THE THIRD COMMANDED A CLB (STILL DSNDING), WHICH WAS INITIATED, AND AFTER GAINING A COUPLE OF HUNDRED FT AT MOST, WE WERE CLR OF CONFLICT. IN EACH CASE WE SAW TFC AFTER GAINING A COUPLE OF HUNDRED FT AT MOST. WE WERE CLR OF CONFLICT. IN EACH CASE WE SAW TFC AFTER GETTING RA MESSAGE. EACH MESSAGE GAVE CORRECT RA. THIS APCH WAS MADE EXTREMELY BUSY AND DIFFICULT, TO WHERE OUR ABILITY TO RECEIVE AND FOLLOW ATC INSTRUCTIONS WERE COMPROMISED. THE CTLR WAS ADVISED OF THIS, AFTER WE MISSED WHAT HE SAID WHILE THE CTLR AND TCASII COMPUTER (AUDIO) WERE TALKING AT THE SAME TIME. THIS HAPPENED MORE THAN ONCE, SIGNIFICANTLY INCREASING THE WORKLOAD FOR ALL OF US. ACCORDING TO CTLR, WE MISSED A HDG CHANGE, AND WERE NOT AWARE OF THIS UNTIL HE QUESTIONED OUR LACK OF RESPONSE. THE ONLY REASON WE WERE ABLE TO FOLLOW RA COMMANDS, WAS BY VISUAL PICTURE ON IVSI, AS CONSTANT CHATTER GARBLED AUDIO MESSAGE. TCASII DOES NOT PRESENTLY FIT INTO ATC SYS, BUT ADDS AN ELEMENT OF INTERRUPTION AND CONFUSION TO AN ALREADY OVERLOADED SYS. NOR DOES IT FIT INTO OUR PRESENT COCKPIT MGMNT, PREVENTING PLTS FROM MAKING TIMELY VERBAL COMMANDS AND ALSO THEIR ABILITY TO UNDERSTAND SAME.

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.

Attempting to follow approach controllers instructions, flight crew of medium large transport was distraction by over loud TCASII alerts and unable to hear controller instructions. Missing a heading change.