Regional Jet 700 ER/LR (CRJ700)
Flight Crew Air Transport Pilot (ATP)
Communication Breakdown; Other / Unknown
ATC Issue All Types
Air Traffic Control Issued New Clearance
Human Factors; Procedure
Upon speaking with Clearance Delivery; to verify our departure/climbout; we were assigned the LGA 4 departure; CONEY climb; off of Runway 13. I programmed the departure/climb out in the FMS/FCP; briefed and verified; cross-referencing my current charts with the FMS/FCP; the departure fixes; altitude restrictions; airspeed restrictions; engine failure procedures; etc. While taxiing; and after completing all appropriate checklists; Ground Control changed our departure to the NTHNS 3. I verified the change with Ground Control; and then proceeded to familiarize myself with all associated parameters and limitations of the departure. I made the appropriate changes to the FMS/FCP/etc. and re-briefed (in detail) all aspects of the departure and re-ran appropriate checklists. While holding short of Runway 13; next in line for takeoff; Tower changed our departure to LGA 4 departure; Whitestone climb. I verified the change again with Tower and advised him that we would need a few minutes to get set up. I; once again; proceeded to familiarize myself with all associated parameters and limitations of the departure. I made the appropriate changes to the FMS/FCP/etc. and re-briefed (in detail) all aspects of the departure and re-ran appropriate checklists. Myself and the Captain were very careful to verify/input/brief properly; as we have had this happen multiple times in LGA and recognize the hazard. We executed the last assigned departure/climb (LGA 4/Whitestone) correctly. During the last part of the Whitestone climb (a left turn from 180 to 040;) and passing through approximately 2;500 FT and a heading of 140; [Controller] asked us to verify that we were on the NTHNS 3 departure. The Captain responded that we were on the Whitestone climb; turning left to heading 040. After a few seconds of radio silence the Captain again stated that we were in a left turn to heading 040. ATC then responded with 'Continue left turn to heading 240; climb/maintain 12;000.' We complied. The remainder of the flight was uneventful. The Captain and myself are 100% certain that we properly executed the last assigned departure and climbout. The ATC Controller seemed agitated but never stated that we did anything incorrectly nor did he query us any further on the issue or give us a phone number to call. The main threat was the normal practice of LGA ATC changing assigned departure/climbout instructions multiple times during taxi (a time of extremely high work-load).
CRJ700 First Officer reports receiving two SID changes from ATC after receiving clearance to taxi to Runway 13 at LGA. Initially LGA 4 Coney climb; then NTHNS 3; then back to LGA 4 with the Whitestone climb. On departure ATC is expecting the crew to be on the NTHNS 3 and issues a new heading.