The pilot of a small aircraft reported that during operation in the hudson river exclusion zone newa...

Narrative:

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.

Original NASA ASRS Text

Title: 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.

Narrative: 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.

Data retrieved from NASA's ASRS site 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.

Attributes
ACN	1312826
Time
Date	201511
Local Time Of Day	1201-1800
Place
Locale Reference	EWR.Airport
State Reference	NJ
Environment
Flight Conditions	VMC
Light	Dusk
Aircraft 1
Make Model Name	Small Aircraft High Wing 1 Eng Fixed Gear
Operating Under FAR Part	Part 91
Flight Phase	Cruise
Flight Plan	VFR
Component
Aircraft Component	Transponder
Person 1
Function	Single Pilot
Qualification	Flight Crew Private
Experience	Flight Crew Last 90 Days 18 Flight Crew Total 310 Flight Crew Type 199
Events
Anomaly	ATC Issue All Types Aircraft Equipment Problem Less Severe Airspace Violation All Types Inflight Event / Encounter Other / Unknown

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.