Narrative:

We were doing practice approachs into bjc. I was flying as the safety pilot. We were flying VFR with no flight plan. We asked den approach for an ILS runway 29 at bjc. We were given an altitude of 7200 ft MSL and a heading towards the approach for the ILS. I am pretty familiar with the airspace, so I did not have my terminal area chart with me. We covered this same ground 3 times, twice for an ILS, once for a VOR/DME, all at 7200 ft MSL. On the third approach, we asked about class B clearance, and the controller gave it to us. When I looked at my tac later, I realized we actually penetrated the airspace on all 3 approachs, and were in the airspace before receiving the clearance on the last approach. The airspace goes down to 7000 ft MSL. I knew we were near their airspace, but since we were given headings and altitudes, I assumed the controller would either keep us out of the airspace or clear us in. Next time, I will have my tac with me and know exactly where the airspace is.

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Original NASA ASRS Text

Title: C172 PLT AND SAFETY PLT, VIOLATED DEN CLASS B AIRSPACE WHILE PRACTICING APCHS TO AN ADJACENT ARPT.

Narrative: WE WERE DOING PRACTICE APCHS INTO BJC. I WAS FLYING AS THE SAFETY PLT. WE WERE FLYING VFR WITH NO FLT PLAN. WE ASKED DEN APCH FOR AN ILS RWY 29 AT BJC. WE WERE GIVEN AN ALT OF 7200 FT MSL AND A HDG TOWARDS THE APCH FOR THE ILS. I AM PRETTY FAMILIAR WITH THE AIRSPACE, SO I DID NOT HAVE MY TERMINAL AREA CHART WITH ME. WE COVERED THIS SAME GND 3 TIMES, TWICE FOR AN ILS, ONCE FOR A VOR/DME, ALL AT 7200 FT MSL. ON THE THIRD APCH, WE ASKED ABOUT CLASS B CLRNC, AND THE CTLR GAVE IT TO US. WHEN I LOOKED AT MY TAC LATER, I REALIZED WE ACTUALLY PENETRATED THE AIRSPACE ON ALL 3 APCHS, AND WERE IN THE AIRSPACE BEFORE RECEIVING THE CLRNC ON THE LAST APCH. THE AIRSPACE GOES DOWN TO 7000 FT MSL. I KNEW WE WERE NEAR THEIR AIRSPACE, BUT SINCE WE WERE GIVEN HDGS AND ALTS, I ASSUMED THE CTLR WOULD EITHER KEEP US OUT OF THE AIRSPACE OR CLR US IN. NEXT TIME, I WILL HAVE MY TAC WITH ME AND KNOW EXACTLY WHERE THE AIRSPACE IS.

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.