Distraction; Confusion; Communication Breakdown; Training / Qualification
Conflict Airborne Conflict
Flight Crew FLC complied w / Automation / Advisory; Flight Crew Took Evasive Action; Flight Crew Requested ATC Assistance / Clarification
Airspace Structure; Human Factors; Procedure
Prior to departure for our flight I briefed the First Officer that there is a lot of VFR traffic and flight training in the vicinity of our destination airport. Well in four miles of that airspace lining up for a right base we got two separate RAs; one to climb and one to descend. Both times we came within 200 ft. vertically of the aircraft which we eventually saw. Plus we got one additional TA for a third aircraft. All three other aircraft were not on approach control's frequency. We had just been handed off from approach control to the tower. Busy airspace with a lot of local flight training from students training at an adjacent airport. Suggest air work flight training not be allowed in the airspace between the two airports.
While on approach and cleared for the Visual Approach by Approach Control we were handed over to Tower. As we were descending through around 5;000 ft. we were receiving multiple targets on the TCAS and after first receiving a TA it quickly turned into an RA. I notified the tower that we were responding to an RA and were told to advise when clear. Shortly after; we received another TA which also turned into an RA. We notified the tower of the second RA and eventually when clear of the second conflict we advised the tower and we were instructed that we were clear to land.Busy airspace due to proximity to a major airport and multiple other airports in the area; the airspace is very busy with both corporate jets and piston aircraft. In short; the immediate airspace was saturated with traffic. Not quite sure what would be a good remedy to prevent this from happening again. Personally; I believe the only way would be to remain on an instrument approach with defined separation from other aircraft. However; that is not always possible in VMC conditions as other aircraft may be operating on a VFR flight plan and not necessarily communicating with ATC. Also the lack of TCAS on most small GA aircraft precludes from safely acquiring traffic.
Corporate flight crew reported responding to two RA's for traffic they had not been advised about when switching from Approach to Tower frequency.