PLT OF PA28 ENTERED LGB CLASS D AIRSPACE WITHOUT 2 WAY COM.

Narrative

I DEPARTED WHITEMAN ARPT IN A CHEROKEE 180; FOR A VFR FLT TO LONG BEACH; CA. I INFORMED WHITEMAN TWR THAT I'D BE TRANSITIONING THROUGH BURBANK CLASS C AIRSPACE. WHITEMAN TWR COORDINATED WITH BURBANK TWR AND ASSIGNED ME A SQUAWK CODE. AFTER LEAVING BURBANK AIRSPACE FREQ CHANGE WAS APPROVED AND CODE WAS CHANGED TO 1200. I WAS AT 1500 FT FLYING S ALONG LOS ANGELES RIVERBED. APPROX 6 MI N OF LONG BEACH ARPT I STARTED CALLING LONG BEACH TWR. I MADE SEVERAL ATTEMPTS TO ESTABLISH 2-WAY COM WITH THE TWR WITH NO OTHER RESULTS. REALIZING THAT LONG BEACH TWR WAS BUSY WITH TFC AND UNABLE TO RESPOND TO MY CALLS I MADE A 180 DEG COURSE REVERSAL AND STARTED TO FLY N ALONG THE RIVERBED. HOWEVER; I WAS ALREADY IN LONG BEACH AIRSPACE AND HAD UNINTENTIONALLY CROSSED INTO IT. AS I WAS TURNING NBOUND I NOTICED 2 AIRPLANES ON EXTENDED R DOWNWIND FOR RWY 16R. MY APPROX ALT WAS BTWN 1200-1300 FT WITH GREATER THAN 1/2 MI DISTANCE FROM 2 DOWNWIND AIRPLANES. AFTER EXITING LONG BEACH AIRSPACE COM WITH LONG BEACH TWR WAS ESTABLISHED FOLLOWED BY CLRNC FOR LNDG ON RWY 16R.