Small Aircraft; High Wing; 1 Eng; Fixed Gear
Flight Crew Private
Flight Crew Last 90 Days 18; Flight Crew Total 310; Flight Crew Type 199
ATC Issue All Types; Aircraft Equipment Problem Less Severe; Airspace Violation All Types; Inflight Event / Encounter Other / Unknown
Air Traffic Control Issued Advisory / Alert; General Maintenance Action
Aircraft
I was flying Southbound down the Hudson River Exclusion Zone (I am familiar with the SFRA Rules and have taken the course online) reporting my location on 123.05. Just before I was about to report 'Hudson River Southbound Piper 1000 ft VZ' Newark Tower came on the channel and called out for Fixed Wing [aircraft] at the VZ. I responded with my tail number and confirmed my location. The tower said I was at 1500 ft and violating Class Bravo Airspace. I replied that my altimeter was set properly and was reporting 1000 ft and in addition that altitude from Stratus/Foreflight was reporting 1000ft as well. Tower replied with altimeter setting which I already had set correctly and I did not hear back from the tower. I continued my flight under VFR through the SFRA. I am confident that I was not in violation of the Class Bravo Airspace. Once entering McGuire airspace I climbed to 2000 ft level and called them for a Mode C check. At 2000 ft level with proper altimeter setting (confirmed with Stratus data) McGuire reported me at 2400 ft. Later when I returned to the airport I was able to upload the data recorded which confirmed my altitude was 1050 ft at the time the EWR tower contacted me. I will be having a pitot/static checked to see what the issue with the transponder reporting the wrong altitude.
The pilot of a small aircraft reported that during operation in the Hudson River Exclusion Zone Newark Tower reported an airspace violation. The aircraft altimeter was reported to be reading on planned altitude; but the transponder or encoder was providing an inaccurate altitude signal.