Close proximity air carrier-medium large transport unk-aircraft on airway east ont.

Attributes
ACN	165484
Time
Date	199012
Day	Fri
Local Time Of Day	0601 To 1200
Place
Locale Reference	atc facility : pdz airport : ont
State Reference	CA
Altitude	msl bound lower : 10000 msl bound upper : 10800
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	tower : dtw
Operator	common carrier : air carrier
Make Model Name	Medium Large Transport, Low Wing, 2 Turbojet Eng
Navigation In Use	Other
Flight Phase	cruise other
Route In Use	enroute airway : ont
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : commercial pilot : flight engineer pilot : atp
Experience	flight time last 90 days : 140 flight time total : 12000 flight time type : 3500
ASRS Report	165484
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 non adherence : clearance
Independent Detector	aircraft equipment other aircraft equipment : unspecified other controllera
Resolutory Action	controller : issued new clearance flight crew : took evasive action other
Consequence	Other
Miss Distance	vertical : 300
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	other

Narrative:

Ziggy arrival to ont airport level at 1000' just coming over mountains by lake arrowhead and approaching valley. Approach called out traffic 5 mi ahead 9500' heading east. It appeared on TCAS scope and I acknowledged xmissions. The target immediately changed to a traffic advisory and I requested a vector since we did not have it visually, and the target indicated a climb and and on a collision course. Controller gave us a left turn to 180 degrees about that time the TCAS dictated a resolution advisory and we started a climb in conjunction with the turn and notified approach of our actions--altitude deviation approximately 800'. Target passed quite close approximately 300' below. We did not endanger any other aircraft with our maneuver and continued the approach. The sequence of events transpired very fast--faster than you really can analyze the situation. The warnings and commands are very authoritative and you react almost out of fright. The command to climb at 1500-2000 FPM could put the aircraft in a dangerous position and it was difficult to stop and return to original altitude.

Original NASA ASRS Text

Title: CLOSE PROX ACR-MLG UNK-ACFT ON AIRWAY EAST ONT.

Narrative: ZIGGY ARR TO ONT ARPT LEVEL AT 1000' JUST COMING OVER MOUNTAINS BY LAKE ARROWHEAD AND APCHING VALLEY. APCH CALLED OUT TFC 5 MI AHEAD 9500' HDG E. IT APPEARED ON TCAS SCOPE AND I ACKNOWLEDGED XMISSIONS. THE TARGET IMMEDIATELY CHANGED TO A TFC ADVISORY AND I REQUESTED A VECTOR SINCE WE DID NOT HAVE IT VISUALLY, AND THE TARGET INDICATED A CLB AND AND ON A COLLISION COURSE. CTLR GAVE US A LEFT TURN TO 180 DEGS ABOUT THAT TIME THE TCAS DICTATED A RESOLUTION ADVISORY AND WE STARTED A CLB IN CONJUNCTION WITH THE TURN AND NOTIFIED APCH OF OUR ACTIONS--ALT DEVIATION APPROX 800'. TARGET PASSED QUITE CLOSE APPROX 300' BELOW. WE DID NOT ENDANGER ANY OTHER ACFT WITH OUR MANEUVER AND CONTINUED THE APCH. THE SEQUENCE OF EVENTS TRANSPIRED VERY FAST--FASTER THAN YOU REALLY CAN ANALYZE THE SITUATION. THE WARNINGS AND COMMANDS ARE VERY AUTHORITATIVE AND YOU REACT ALMOST OUT OF FRIGHT. THE COMMAND TO CLB AT 1500-2000 FPM COULD PUT THE ACFT IN A DANGEROUS POS AND IT WAS DIFFICULT TO STOP AND RETURN TO ORIGINAL ALT.

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.