B737-800
Flight Crew Air Transport Pilot (ATP); Flight Crew Instrument; Flight Crew Multiengine
Flight Crew Type 438
Communication Breakdown; Confusion; Situational Awareness; Workload
ATC Issue All Types; Airspace Violation All Types; Deviation - Altitude Crossing Restriction Not Met; Deviation - Altitude Overshoot; Deviation / Discrepancy - Procedural Clearance; Deviation / Discrepancy - Procedural Published Material / Policy
Air Traffic Control Issued Advisory / Alert; Flight Crew Became Reoriented
Human Factors; Procedure
Upon receiving clearance to proceed and descend via the ANJLL 4 RNAV arrival; we were given multiple changes from ATC. We were cleared after HACKMN to OTOOLE for the ANJLLL 4 Arrival except to maintain 12;500' for Military Airspace. He then cleared us direct OTOOLE after verification of the original clearance. We were then cleared direct to CAANN and maintain 300 knots. This put the aircraft in a high energy state and high. The Captain tried to use speedbrakes and Level Change to dissipate energy. We were then given 280 knots. That changed our energy state. We were then told to maintain 14;000'. The Controller then queried us why we went through the CAANN restriction of at or above 17;000' and said we left his airspace. There was just a lot of confusion on what altitude; what fix; and what airspeed we were given from SoCal in such a short span that we ended up just complying with the remaining instructions and came in for an uneventful landing.There should not be so many clearance changes to altitude; entry fix; proceeding direct off the arrival; and airspeed changes in such a busy airspace.
B737-800 First Officer reported overshooting an altitude restriction on arrival into LAX; citing multiple changes to their clearance as contributing.