Gulfstream V / G500 / G550
Flight Crew Air Transport Pilot (ATP)
Flight Crew Last 90 Days 30; Flight Crew Total 20000; Flight Crew Type 600
Human-Machine Interface
Aircraft Equipment Problem Less Severe; Conflict NMAC; Deviation - Altitude Excursion From Assigned Altitude
Flight Crew Took Evasive Action
Procedure; Human Factors; Airspace Structure
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.
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.