When advised by approach control he had violated the floor of the san diego class B when transiting ...

Narrative:

A routine flight was made to sdm. This was one of nine flights performed to sdm for the month; tracking basically the same flight path as the previous flights. A garmin 430 (certified for IFR flight with a current card) with a moving map display was programmed and activated to go GPS direct to sdm; the VOR (poggi-109.8) radial 350 (170 heading). Upon departing we proceeded southbound to sdm via the eastern side over sweetwater reservoir. The course was flown underneath class bravo airspace with the floor varying between 4;800 MSL and 1;800 MSL and 300 MSL. At all the times the aircraft was operated below the floor of class bravo airspace. Upon landing at sdm; the controller asked that I contact the approach control supervisor. I complied and contacted him via phone. I informed approach control that I remained clear of the class bravo airspace at all times and had checked my position via GPS and VFR waypoints to ensure an incursion into the airspace would not and did not occur. As a result of events of the day; I retraced the flight later that evening with a class bravo clearance. Upon passing north of sweetwater reservoir; a VFR waypoint; and the point at which the floor of class bravo airspace changes from 1;800 MSL to 3;000 MSL; the controller was asked the verify the floor of the airspace above. The controller stated 1;800 MSL. I verified my position via GPS and the VFR waypoint (sweetwater reservoir) and confirmed that pursuant to the marking of class bravo airspace on the VFR chart; san diego that the floor of class bravo airspace indicated to be 3;000 MSL at that position. The overlay of class bravo airspace as shown on the VFR terminal chart; san diego with respect to ATC radar and GPS receiver should be verified.

Original NASA ASRS Text

Title: When advised by Approach Control he had violated the floor of the San Diego Class B when transiting to SDM; the pilot of a GPS equipped C150 advised he had not and suggested the accuracy of local area charts compared to ATC radar be examined.

Narrative: A routine flight was made to SDM. This was one of nine flights performed to SDM for the month; tracking basically the same flight path as the previous flights. A Garmin 430 (certified for IFR flight with a current card) with a moving map display was programmed and activated to go GPS direct to SDM; the VOR (POGGI-109.8) radial 350 (170 heading). Upon departing we proceeded southbound to SDM via the eastern side over Sweetwater Reservoir. The course was flown underneath Class Bravo Airspace with the floor varying between 4;800 MSL and 1;800 MSL and 300 MSL. At all the times the aircraft was operated below the floor of class Bravo Airspace. Upon landing at SDM; the Controller asked that I contact the Approach Control Supervisor. I complied and contacted him via phone. I informed Approach Control that I remained clear of the Class Bravo Airspace at all times and had checked my position via GPS and VFR waypoints to ensure an incursion into the airspace would not and did not occur. As a result of events of the day; I retraced the flight later that evening with a Class Bravo clearance. Upon passing north of Sweetwater Reservoir; a VFR waypoint; and the point at which the floor of Class Bravo Airspace changes from 1;800 MSL to 3;000 MSL; the Controller was asked the verify the floor of the airspace above. The Controller stated 1;800 MSL. I verified my position via GPS and the VFR waypoint (Sweetwater Reservoir) and confirmed that pursuant to the marking of Class Bravo Airspace on the VFR chart; San Diego that the floor of Class Bravo Airspace indicated to be 3;000 MSL at that position. The overlay of Class Bravo Airspace as shown on the VFR terminal chart; San Diego with respect to ATC radar and GPS receiver should be verified.

Data retrieved from NASA's ASRS site as of July 2013 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	1006820
Time
Date	201204
Local Time Of Day	1201-1800
Place
Locale Reference	SAN.Airport
State Reference	CA
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Make Model Name	Cessna 150
Operating Under FAR Part	Part 91
Flight Phase	Cruise
Route In Use	Direct
Flight Plan	None
Person 1
Function	Single Pilot
Qualification	Flight Crew Air Transport Pilot (ATP) Flight Crew Multiengine Flight Crew Instrument Flight Crew Flight Instructor Flight Crew Commercial
Experience	Flight Crew Last 90 Days 39.7 Flight Crew Total 12466 Flight Crew Type 1890
Events
Anomaly	ATC Issue All Types Airspace Violation All Types

When advised by approach control he had violated the floor of the san diego class B when transiting to sdm; the pilot of a GPS equipped C150 advised he had not and suggested the accuracy of local area charts compared to ATC radar be examined.