G550 captain experiences a TCAS RA at 3;000 ft while being vectored for the ILS at teb. The initial ...

Attributes
ACN	1132757
Time
Date	201311
Local Time Of Day	1201-1800
Place
Locale Reference	TEB.Airport
State Reference	NY
Environment
Flight Conditions	IMC
Aircraft 1
Make Model Name	Gulfstream V / G500 / G550
Operating Under FAR Part	Part 91
Flight Phase	Initial Approach
Route In Use	Vectors
Flight Plan	IFR
Component
Aircraft Component	Traffic Collision Avoidance System (TCAS)
Person 1
Function	Captain
Qualification	Flight Crew Air Transport Pilot (ATP)
Experience	Flight Crew Last 90 Days 30 Flight Crew Total 20000 Flight Crew Type 600
Events
Anomaly	Aircraft Equipment Problem Less Severe Conflict NMAC Deviation - Altitude Excursion From Assigned Altitude
Miss Distance	Horizontal 100 Vertical 100

Narrative:

Being vectored for approach to ILS 19 at teb IMC at 3;000 ft MSL; 190 KTS; received a TA followed immediately by an RA descend command and within one second RA reversed to a climb; then an increase climb command. Topped out at 3;800 ft MSL. RA was displaying -500 then -100 and the RA commenced. The issue was the initial descend command with the target below us. It didn't make sense; but followed the commands and they reversed themselves to a climb shortly after the descent. No visual on the conflicting traffic. Approach was moderately busy and did not provide a traffic advisory. Training is to always follow the TCAS commands and we did. This G550 is equipped with certification F [cpdlc software] and submitting this to crosscheck if other like equipped G550s have had similar reversal ras.

Original NASA ASRS Text

Title: G550 Captain experiences a TCAS RA at 3;000 FT while being vectored for the ILS at TEB. The initial RA is to descend and is then reversed to a climb; then an increase climb. The reporter was in IMC and did not see the intruder and ATC did not provide a traffic advisory.

Narrative: Being vectored for approach to ILS 19 at TEB IMC at 3;000 FT MSL; 190 KTS; received a TA followed immediately by an RA descend command and within one second RA reversed to a climb; then an increase climb command. Topped out at 3;800 FT MSL. RA was displaying -500 then -100 and the RA commenced. The issue was the initial descend command with the target below us. It didn't make sense; but followed the commands and they reversed themselves to a climb shortly after the descent. No visual on the conflicting traffic. Approach was moderately busy and did not provide a traffic advisory. Training is to always follow the TCAS commands and we did. This G550 is equipped with Certification F [CPDLC Software] and submitting this to crosscheck if other like equipped G550s have had similar reversal RAs.

Data retrieved from NASA's ASRS site as of July 2013 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.

G550 captain experiences a TCAS RA at 3;000 ft while being vectored for the ILS at teb. The initial RA is to descend and is then reversed to a climb; then an increase climb. The reporter was in IMC and did not see the intruder and ATC did not provide a traffic advisory.