Narrative:

After landing at metropolitan oakland on runway 27R, I was directed to back-taxi on runway 9L for a left downwind departure to the northwest. The tower controller asked if I would need radar services my return flight to ccr. I replied that I would not be necessary, since I encountered very little GA traffic along the same route a few mins earlier. Also, the controller for bay approach seemed to be working several large sectors at the same time, so I didn't want to add any more unnecessary workload on his shoulders. The tower instructed me to squawk VFR (1200) and cleared me for takeoff. After departure, I climbed to the altitude I had flown inbound mins earlier -- 2500 ft MSL -- and advised the tower that I wanted to circle lake merritt before proceeding northwest toward richmond, which was approved as requested. As I approached lake merritt, the tower controller advised that I was leaving his airspace and that a frequency change was approved. It was then I realized that I had just entered the secondary ring for the oak class C airspace at 2500 ft MSL and was no longer in 2-WAY communication with ATC (the effective altitudes for the ring in that sector were from 1500 ft MSL to the base of the overlying class B airspace, which was at 3000 ft MSL). I immediately started a descent to 1400 ft MSL, which took about 1 min to complete. I decided against orbiting lake merritt and continued northwest until I had flown past the northern boundary of the oak class C airspace, at which point I climbed back to 2500 ft MSL and continued my flight. Although I had communicated with bay approach on my inbound leg, I did not attempt to contact them throughout this period or afterward. Although I had flown this route several times at night, this was the first time that I was instructed to squawk VFR before departure (because I had declined radar services) and also the first time 2-WAY radio communication was severed by ATC while I was still within the confines of class C airspace. (In the past, I've been instructed to contact bay departure or I remained with the local controller until past the northern boundary of class C, whereupon I was advised that 'frequency change was approved.') in the future, it is my intention to more carefully distinguish the boundaries of responsibility between the approach/departure and local controllers and to fly accordingly. It is my suggestion that even though it is not the local controller's responsibility to keep VFR traffic from violating class C airspace in the manner in which I did, he was in a position to correct the violation before it happened -- traffic was very light, and I think I was the only aircraft he was working at the time.

Related reports:

Google
 

Original NASA ASRS Text

Title: A PIPER CHEROKEE PLT ENTERED OAK CLASS C AIRSPACE WITHOUT A CLRNC.

Narrative: AFTER LNDG AT METRO OAKLAND ON RWY 27R, I WAS DIRECTED TO BACK-TAXI ON RWY 9L FOR A L DOWNWIND DEP TO THE NW. THE TWR CTLR ASKED IF I WOULD NEED RADAR SVCS MY RETURN FLT TO CCR. I REPLIED THAT I WOULD NOT BE NECESSARY, SINCE I ENCOUNTERED VERY LITTLE GA TFC ALONG THE SAME RTE A FEW MINS EARLIER. ALSO, THE CTLR FOR BAY APCH SEEMED TO BE WORKING SEVERAL LARGE SECTORS AT THE SAME TIME, SO I DIDN'T WANT TO ADD ANY MORE UNNECESSARY WORKLOAD ON HIS SHOULDERS. THE TWR INSTRUCTED ME TO SQUAWK VFR (1200) AND CLRED ME FOR TKOF. AFTER DEP, I CLBED TO THE ALT I HAD FLOWN INBOUND MINS EARLIER -- 2500 FT MSL -- AND ADVISED THE TWR THAT I WANTED TO CIRCLE LAKE MERRITT BEFORE PROCEEDING NW TOWARD RICHMOND, WHICH WAS APPROVED AS REQUESTED. AS I APCHED LAKE MERRITT, THE TWR CTLR ADVISED THAT I WAS LEAVING HIS AIRSPACE AND THAT A FREQ CHANGE WAS APPROVED. IT WAS THEN I REALIZED THAT I HAD JUST ENTERED THE SECONDARY RING FOR THE OAK CLASS C AIRSPACE AT 2500 FT MSL AND WAS NO LONGER IN 2-WAY COM WITH ATC (THE EFFECTIVE ALTS FOR THE RING IN THAT SECTOR WERE FROM 1500 FT MSL TO THE BASE OF THE OVERLYING CLASS B AIRSPACE, WHICH WAS AT 3000 FT MSL). I IMMEDIATELY STARTED A DSCNT TO 1400 FT MSL, WHICH TOOK ABOUT 1 MIN TO COMPLETE. I DECIDED AGAINST ORBITING LAKE MERRITT AND CONTINUED NW UNTIL I HAD FLOWN PAST THE NORTHERN BOUNDARY OF THE OAK CLASS C AIRSPACE, AT WHICH POINT I CLBED BACK TO 2500 FT MSL AND CONTINUED MY FLT. ALTHOUGH I HAD COMMUNICATED WITH BAY APCH ON MY INBOUND LEG, I DID NOT ATTEMPT TO CONTACT THEM THROUGHOUT THIS PERIOD OR AFTERWARD. ALTHOUGH I HAD FLOWN THIS RTE SEVERAL TIMES AT NIGHT, THIS WAS THE FIRST TIME THAT I WAS INSTRUCTED TO SQUAWK VFR BEFORE DEP (BECAUSE I HAD DECLINED RADAR SVCS) AND ALSO THE FIRST TIME 2-WAY RADIO COM WAS SEVERED BY ATC WHILE I WAS STILL WITHIN THE CONFINES OF CLASS C AIRSPACE. (IN THE PAST, I'VE BEEN INSTRUCTED TO CONTACT BAY DEP OR I REMAINED WITH THE LCL CTLR UNTIL PAST THE NORTHERN BOUNDARY OF CLASS C, WHEREUPON I WAS ADVISED THAT 'FREQ CHANGE WAS APPROVED.') IN THE FUTURE, IT IS MY INTENTION TO MORE CAREFULLY DISTINGUISH THE BOUNDARIES OF RESPONSIBILITY BTWN THE APCH/DEP AND LCL CTLRS AND TO FLY ACCORDINGLY. IT IS MY SUGGESTION THAT EVEN THOUGH IT IS NOT THE LCL CTLR'S RESPONSIBILITY TO KEEP VFR TFC FROM VIOLATING CLASS C AIRSPACE IN THE MANNER IN WHICH I DID, HE WAS IN A POS TO CORRECT THE VIOLATION BEFORE IT HAPPENED -- TFC WAS VERY LIGHT, AND I THINK I WAS THE ONLY ACFT HE WAS WORKING AT THE TIME.

Data retrieved from NASA's ASRS site as of July 2007 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.