Date: 201708
Local time of day: 0001-0600
Location: LGA.Airport, NY
Flight conditions: VMC
Light: Daylight
Aircraft: Regional Jet 900 (CRJ900)
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Passenger
Flight phase: Initial Approach
Airspace: Class B NYC
ATC / advisory: Tower LGA
Second aircraft: Helicopter
Reporter organization: Air Carrier
Reporter function: Pilot Flying; First Officer
Reporter qualification: Flight Crew Air Transport Pilot (ATP)
Human factors: Confusion; Situational Awareness; Communication Breakdown
Anomaly: Conflict Airborne Conflict; Deviation / Discrepancy - Procedural Published Material / Policy
Detector: Automation Aircraft TA; Automation Aircraft RA
When detected: In-flight
Result: Flight Crew Became Reoriented; Flight Crew Took Evasive Action
Contributing factors: Human Factors; Procedure
Primary problem: Human Factors

Narrative: Going into LaGuardia we had just been vectored onto base for the ILS 22; had called airport in sight; and had been cleared for the visual approach. We had been assigned about a 130 heading prior to being cleared for the visual so I set the heading to approximately 180 to join the LOC at GREKO thus shallow our localizer intercept angle; I also selected approach mode. We were already in a descent to 2000 ft; approaching 3000 ft; and I noted we were high on the glideslope; so I set 1000 ft into the FCP and increased our rate of descent to 1500 FPM. My intention was to descend faster initially till we were closer to the glideslope; then shallow the descent to make sure the glideslope would capture at GREKO; not ALTSCAP at 2000 before GS intercept (GS altitude is 1900 at GREKO). As we descended we got a 'TRAFFIC' TA. Glancing at the map I noted traffic about 1500 ft below us and moving from right to left; and I thought it would be a transitory TA and clear shortly as we passed. The Captain; who was pilot monitoring; then called out something like 'you need 1000 FPM'. For some reason I mistakenly thought he was referring to the stabilized approach criteria and continued; since I was about to reduce my rate of descent in a few seconds anyway for the glideslope. He repeated himself and I acknowledged and began to spin the vertical speed wheel to reduce the rate of descent. At this point The TA switched to an RA though I don't recall hearing an audible command. Looking at the VSI I saw it was red with a single green line at 0 indicating we needed to level off. It took me a few seconds to process this; move my hand back to the yoke since it had been on the FCP; click off the auto-pilot; and pull back to arrest the descent. At this point according to the display the traffic was 300 ft below us and off to our left; moving away. The Captain called the RA in to tower and I continued to hand fly the rest of the approach; joining the ILS and landing. The traffic turned out to be a helicopter though I do not recall ATC calling them out at any point prior to the TA/RA nor did I ever see the traffic. The tricky thing about this event was that there were multiple things happening simultaneously. My mind was focused on efficiently joining the approach and not thinking of the possibility of the traffic becoming a conflict; especially since I had not heard the traffic called by ATC. When the SA happened my attention was split between visually flying the approach and looking for traffic; managing the automation; and keeping track of the traffic on TCAS; and trying to decide how best to handle them all at once; which led to a slow reaction. After we landed the Captain said that for a TA you are to reduce your rate of climb/descent to 1000 FPM or less which is what he meant by his call of me needing '1000 FPM' though I don't recall that from training. He may have intended the reduced rate of descent as a command which I interpreted as only a suggestion and thus I didn't react with as much urgency as I should have. This was also my first time having an actual RA and not simply a TA that resolved itself without any need for action. I think the combination of it being not unusual; especially in busy airspace; to have a TA that resolves itself without any maneuvering combined with all RA's in training being JUST an RA (in other words; you're expecting to deal with an RA; not doing a complicated maneuver and then an TA/RA happens unexpectedly) also contributed to my reactions not being as swift as I would have liked.




Synopsis: CRJ-900 First Officer reported a NMAC while on approach as they were too slow to react to a RA from a helicopter.