A BA46 flight crew lost separation after responding to a TCASII RA from crossing traffic at a lower ...

Attributes
ACN	451430
Time
Date	199910
Day	Wed
Local Time Of Day	0601 To 1200
Place
Locale Reference	airport : ith.airport
State Reference	NY
Altitude	msl single value : 33000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zbw.artcc
Operator	common carrier : air carrier
Make Model Name	BAe 146 Undifferentiated or Other Model
Operating Under FAR Part	Part 121
Navigation In Use	other
Flight Phase	cruise : level
Flight Plan	IFR
Aircraft 2
Controlling Facilities	artcc : zbw.artcc
Operator	general aviation : corporate
Make Model Name	Gates Learjet Corp Undifferentiated or Other Model
Operating Under FAR Part	Part 91
Flight Phase	cruise : level
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp pilot : multi engine pilot : instrument pilot : cfi
Experience	flight time last 90 days : 250 flight time total : 12500 flight time type : 2000
ASRS Report	451430
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : multi engine pilot : instrument pilot : commercial
Events
Anomaly	aircraft equipment problem : less severe altitude deviation : excursion from assigned altitude conflict : airborne less severe
Independent Detector	aircraft equipment : tcas other controllera other flight crewa other flight crewb
Resolutory Action	controller : issued alert flight crew : returned to assigned altitude
Consequence	faa : investigated other
Miss Distance	horizontal : 12000 vertical : 1200
Supplementary
Problem Areas	Aircraft
Primary Problem	Aircraft

Narrative:

Received an RA on TCASII as learjet passed our 7-8 O'clock position at FL310. We were at FL330. TCASII commanded us to descend with RA target indicating in our 7 O'clock position. Descended at 800 ft which violated separation on the lear. ATC said there was no other traffic in the vicinity except the lear. Notified me the tapes were being pulled for review. They have also filed it as an incident. We as a crew did everything we were trained to do -- we must always follow TCASII when visual contact cannot be made. However, this seems like it may have been false.

Original NASA ASRS Text

Title: A BA46 FLC LOST SEPARATION AFTER RESPONDING TO A TCASII RA FROM XING TFC AT A LOWER ALT NEAR ITH.

Narrative: RECEIVED AN RA ON TCASII AS LEARJET PASSED OUR 7-8 O'CLOCK POS AT FL310. WE WERE AT FL330. TCASII COMMANDED US TO DSND WITH RA TARGET INDICATING IN OUR 7 O'CLOCK POS. DSNDED AT 800 FT WHICH VIOLATED SEPARATION ON THE LEAR. ATC SAID THERE WAS NO OTHER TFC IN THE VICINITY EXCEPT THE LEAR. NOTIFIED ME THE TAPES WERE BEING PULLED FOR REVIEW. THEY HAVE ALSO FILED IT AS AN INCIDENT. WE AS A CREW DID EVERYTHING WE WERE TRAINED TO DO -- WE MUST ALWAYS FOLLOW TCASII WHEN VISUAL CONTACT CANNOT BE MADE. HOWEVER, THIS SEEMS LIKE IT MAY HAVE BEEN FALSE.

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.

A BA46 flight crew lost separation after responding to a TCASII RA from crossing traffic at a lower altitude near ith.