Flight Crew Multiengine; Flight Crew Air Transport Pilot (ATP)
Flight Crew Last 90 Days 100; Flight Crew Total 4700; Flight Crew Type 100
Confusion; Situational Awareness
ATC Issue All Types; Airspace Violation All Types; Conflict Airborne Conflict
Air Traffic Control Provided Assistance; Flight Crew Took Evasive Action
Human Factors; Airspace Structure
VFR flight from to [Airport X]. Level at 9;500 MSL and approximately 10 miles outside the outer limit of Denver Class B airspace I was switched over to Denver Approach. I checked in and requested clearance into Class B airspace. This request was denied and I was told to remain clear of Class B airspace and to descend below. I made a decent to 8;500 MSL to fly below the outer layer of Class B airspace with a floor of 9;000 feet MSL. The next layer of Class B airspace had a floor of 8;000 feet MSL. I again requested clearance into Class B airspace and was told that I would not be cleared into the airspace and that they handle 100's of aircraft VFR in and out of [Airport X] each day. I informed the controller I did not want to descend below the 8;000 MSL layer until I was closer to [Airport X]. I was then informed by the controller that the floor of the airspace in front of me was 10;000 MSL. I responded that my charts said 8;000 MSL and started a descend to 7;800 MSL to remain clear of the Class B airspace. As soon I leveled at 7;800 to remain clear of the airspace a traffic contact 500 below me came up on my TCAS as a yellow target. [Airport X] tower informed me of the traffic; said he thought they were talking to Denver Approach and that I might need to make a turn or climb to avoid the traffic if they continued to climb. The traffic did not level off and my TCAS gave me an RA 'Traffic; Climb Climb!' I responded as necessary which caused me to climb into the Class B airspace at an altitude of 8300 MSL. Where I temporarily leveled until my TCAS gave me the RA clear message and then I descended back to 7;800 MSL.
Aircraft responded to a Resolution Advisory (RA) while on approach. During the evasive event there was a possible incursion into class B airspace; but it is not clear that it actually occurred. Denver approach control did not state as such.