Small Aircraft; Low Wing; 1 Eng; Fixed Gear
Flight Crew Private; Flight Crew Instrument
Flight Crew Last 90 Days 31; Flight Crew Total 955; Flight Crew Type 955
Time Pressure
Conflict NMAC
Flight Crew Took Evasive Action
Airspace Structure; Human Factors
Heading Eastbound at 4;800 [feet] MSL; above the LGB Delta airspace; and below the 5;000 Bravo shelf. Ceiling was unlimited at my position; clear below me; with visibility 10+ miles; except for low clouds extending eastward from the NW to SE approximately 3;000 feet laterally from my position; with tops about 4;800 MSL. As I was beginning to turn southeastward to keep cloud clearance and head for a higher Bravo floor; I received a TCAS traffic alert; 100 feet below; less than 1 mile; at my 11:00 [position]. I took immediate evasive measures including climbing and turning faster to the south. I curtailed my climb abruptly at the floor of Bravo. While I did not ever see the actual traffic conflict (in a turning climb away from target); the TCAS target appeared to cross almost directly under me; with only 300 feet separation. Knowledge of the Bravo shelf kept me from aggressively climbing to avoid the conflict. Had Bravo shelf not been there; I would have climbed much more aggressively higher.
GA pilot reported a NMAC that required an evasive maneuver while operating between the ceiling of Delta airspace and the floor of Bravo airspace.