TCASII induced less than standard separation. Air carrier X TCASII RA with VFR aircraft non compliance with ATC clearance unauthorized descent from assigned altitude had less than standard separation with light transport. Pilot deviation.

Home

Browse by month

Random

Latest

About

Contact

Attributes
ACN	239498
Time
Date	199304
Day	Thu
Local Time Of Day	1201 To 1800
Place
Locale Reference	atc facility : pdz
State Reference	CA
Altitude	msl bound lower : 8000 msl bound upper : 8600
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	tracon : ont
Operator	common carrier : air carrier
Make Model Name	Large Transport, Low Wing, 2 Turbojet Eng
Navigation In Use	Other Other
Flight Phase	cruise other descent other
Route In Use	enroute : on vectors
Flight Plan	IFR
Aircraft 2
Operator	common carrier : air carrier
Make Model Name	Light Transport, Low Wing, 2 Turboprop Eng
Flight Phase	climbout : intermediate altitude cruise other
Route In Use	enroute : direct
Flight Plan	IFR
Person 1
Affiliation	government : faa
Function	controller : approach
Qualification	controller : radar
Experience	controller military : 4 controller non radar : 9 controller radar : 2
ASRS Report	239498
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Events
Anomaly	altitude deviation : excursion from assigned altitude conflict : airborne less severe non adherence : required legal separation non adherence : clearance
Independent Detector	aircraft equipment other aircraft equipment : unspecified other controllera
Resolutory Action	controller : issued new clearance other
Consequence	Other
Miss Distance	horizontal : 9000 vertical : 600
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

Air carrier X level at 10000 ft swbound. VFR traffic at 10500 ft ahead and to the right, and VFR traffic at 10000 ft nebound. The VFR nebound was turned to heading of 030 degrees. Air carrier X was turned 20 degrees left, away from both VFR targets. Air carrier X had a TCASII resolution and descended to 8600 ft. There was an light transport sebound climbing out of 7000 ft to 9000 ft. The light transport was leveled off at 8000 ft and saw the air carrier X pass in front of him. The 2 aircraft came within 600 ft and 1 1/2 mi. I think the TCASII system should be adjusted so that the TCASII resolution doesn't go off unless the aircraft will be less than 500 ft vertical and less than a mi horizontally.

Original NASA ASRS Text

Title: TCASII INDUCED LTSS. ACR X TCASII RA WITH VFR ACFT NON COMPLIANCE WITH ATC CLRNC UNAUTH DSCNT FROM ASSIGNED ALT HAD LTSS WITH LTT. PLTDEV.

Narrative: ACR X LEVEL AT 10000 FT SWBOUND. VFR TFC AT 10500 FT AHEAD AND TO THE R, AND VFR TFC AT 10000 FT NEBOUND. THE VFR NEBOUND WAS TURNED TO HDG OF 030 DEGS. ACR X WAS TURNED 20 DEGS L, AWAY FROM BOTH VFR TARGETS. ACR X HAD A TCASII RESOLUTION AND DSNDED TO 8600 FT. THERE WAS AN LTT SEBOUND CLBING OUT OF 7000 FT TO 9000 FT. THE LTT WAS LEVELED OFF AT 8000 FT AND SAW THE ACR X PASS IN FRONT OF HIM. THE 2 ACFT CAME WITHIN 600 FT AND 1 1/2 MI. I THINK THE TCASII SYS SHOULD BE ADJUSTED SO THAT THE TCASII RESOLUTION DOESN'T GO OFF UNLESS THE ACFT WILL BE LESS THAN 500 FT VERT AND LESS THAN A MI HORIZLY.

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.