Narrative:

This was a short repositioning flight from tmb to fll. Because of thunderstorms to the east of tmb, I elected to depart tmb to the northwest and then to the west of the miami class B airspace at 1500 ft. I was giving the 10 mi ring around mia about a 1.5 mi buffer (using a GPS with a current database). The base in the class B airspace in that area is 3000 ft. I look over to my right and saw a BE1900 750-1000 ft to my right (he had come up from behind). He began a climb and I descended. He then turned right and crossed above me inbound to miami (I would guess). This was pretty close. I am worried that I might have been too close to the class B airspace even though the GPS showed I was 1.5 mi west of the 1500 ft floor. I called up fll about 5 mins later for flight following into fll and landed uneventfully. In looking at the chart later, it looks like I was west of a canal that was also west of the 10 mi ring. Looking at the regulation, there is no requirement for ATC to have the BE1900 inside the class B airspace although the low ceiling and convective activity may have pushed him down to 1500 ft sooner.

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Original NASA ASRS Text

Title: VFR MOONEY M20K PLT TRAVERSING JUST OUTSIDE OF THE MIA CLASS B AIRSPACE HAS CLOSE ENCOUNTER WITH A BEECH 1900 GOING TO MIA.

Narrative: THIS WAS A SHORT REPOSITIONING FLT FROM TMB TO FLL. BECAUSE OF TSTMS TO THE E OF TMB, I ELECTED TO DEPART TMB TO THE NW AND THEN TO THE W OF THE MIAMI CLASS B AIRSPACE AT 1500 FT. I WAS GIVING THE 10 MI RING AROUND MIA ABOUT A 1.5 MI BUFFER (USING A GPS WITH A CURRENT DATABASE). THE BASE IN THE CLASS B AIRSPACE IN THAT AREA IS 3000 FT. I LOOK OVER TO MY R AND SAW A BE1900 750-1000 FT TO MY R (HE HAD COME UP FROM BEHIND). HE BEGAN A CLB AND I DSNDED. HE THEN TURNED R AND CROSSED ABOVE ME INBOUND TO MIAMI (I WOULD GUESS). THIS WAS PRETTY CLOSE. I AM WORRIED THAT I MIGHT HAVE BEEN TOO CLOSE TO THE CLASS B AIRSPACE EVEN THOUGH THE GPS SHOWED I WAS 1.5 MI W OF THE 1500 FT FLOOR. I CALLED UP FLL ABOUT 5 MINS LATER FOR FLT FOLLOWING INTO FLL AND LANDED UNEVENTFULLY. IN LOOKING AT THE CHART LATER, IT LOOKS LIKE I WAS W OF A CANAL THAT WAS ALSO W OF THE 10 MI RING. LOOKING AT THE REG, THERE IS NO REQUIREMENT FOR ATC TO HAVE THE BE1900 INSIDE THE CLASS B AIRSPACE ALTHOUGH THE LOW CEILING AND CONVECTIVE ACTIVITY MAY HAVE PUSHED HIM DOWN TO 1500 FT SOONER.

Data retrieved from NASA's ASRS site as of July 2007 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.