Cessna 210 Centurion / Turbo Centurion 210C; 210D
Flight Crew Private; Flight Crew Instrument
Flight Crew Last 90 Days 30; Flight Crew Total 4500; Flight Crew Type 3500
Aircraft Equipment Problem Less Severe; Airspace Violation All Types; Deviation / Discrepancy - Procedural FAR
General None Reported / Taken
Airspace Structure; Procedure
When departing HWD heading 010 and approximately 3 nm from the airport; all GPS signal was lost on both Garmin WASS receivers and 1 portable. The signal was restored at about 5nm. The loss of positional awareness may have caused the aircraft to climb above 1500 ft. and into Oakland Class C airspace. This loss of signal also happened on another occasion. During this time period; the RNAV 28L approach was NOTAMed out of service. When I asked the Hayward Tower about the loss of signal - they did not know of the loss of signal. A NOTAM should have been issued that there was GPS signal loss in this area.
C210 pilot reported momentary loss of GPS signal while departing HWD airport.