Cessna 210 Centurion / Turbo Centurion 210C; 210D
Flight Crew Air Transport Pilot (ATP); Flight Crew Multiengine
Flight Crew Last 90 Days 30; Flight Crew Total 3000; Flight Crew Type 700
Human-Machine Interface; Situational Awareness
Airspace Violation All Types
Air Traffic Control Issued Advisory / Alert; Air Traffic Control Issued New Clearance; Flight Crew Became Reoriented
Aircraft; Airspace Structure; Human Factors
While responding on a law enforcement mission in a state aircraft to a location near a towered airport below Class B airspace; we set up an orbit over the location of the report at 4;500 FT MSL. We later discovered that half of our orbit was inside the Class B airspace and the other half of the orbit was clear of controlled airspace. After departing the primary airport; and being given a heading to turn southbound; Tower handed us to TRACON. We had climbed to 4;500 FT MSL before we had an opportunity to check in with TRACON and advised TRACON that we were at 4;500 FT and requesting direct to the scene (approximately 15 miles southeast of our current position). TRACON advised we were clear of the Bravo and to squawk 1200. Approximately 10 miles west of ZZZ we contacted ZZZ Tower and advised we were at 4;500 FT and would be over their airspace (top of ZZZ Class D airspace is 3;000) and were calling as a courtesy. After approximately 10 minutes; ZZZ Tower asked if we were still monitoring their frequency and to call TRACON. We did so and TRACON advised that we had been flying into and out of a slice of the Class B airspace based on our altitude of 4;500 FT. The section of airspace that we were clear of became controlled at 5;000 FT (the airspace we were in after being instructed to squawk 1200 after our initial call to TRACON after departing.) Of note: We use commercially available geo-referenced iPad software to show aircraft position over an electronic sectional chart. Before departing; a direct route was plotted from our hangar to ZZZ. The software displayed a solid magenta line. That magenta line showing the direct course; aligned perfectly with the Class B airspace boundary that marked the Class B floor change from 5;000 FT MSL to 4;500 FT [4;000] MSL. This magenta line obscured the Class B boundary line that we ended up flying over during our orbit(s). After contacting TRACON; we asked for and received a squawk and clearance; and remained on scene until released by ground officers. Continued vigilance of airspace altitude changes; with respect to locating our ground target (visually) is required to prevent a repeat occurrence. Asking TRACON for continued flight following; instead of accepting their request to squawk 1200 during the initial call to TRACON and not plotting a direct course that obscured the airspace boundary would have aided in preventing this occurrence.
C210 pilot reports inadvertently orbiting in and out of Class B airspace on a law enforcement mission. An iPad was being used for navigation and a magenta course line from the departure airport to the scene coincided with and obscured a line denoting a Class B floor change from 5;000 FT to 4;000 FT.