Narrative:

I was over the town of monument, co, at 10500 ft MSL after having flown around over the hills to the west. I set up for a cruise descent back to my base at centennial airport, tuned, idented, and turned toward the casse NDB, and then tuned in and noted centennial's ATIS. A few mi south of castle rock, at 10000 ft MSL and a little east of I25 (the main highway), I glanced at the den terminal chart to see where the class B began, and was horrified to see that I was close to penetrating that airspace, if I had not done so already. I had somehow thought that the boundary was north of castle rock. I pulled the throttle all the way back and began a 1000 FPM descending left turn back to the south. When I was down to 8500 ft MSL, I turned back to the north and continued toward centennial. As I arrived over the point where I had first noticed the possible incursion, I noted that the LORAN, which is not very accurate, indicated that I was 18.3 mi from centennial. On my den terminal chart I measured the distance from centennial to the edge of the class B (in the direction of castle rock) to be roughly 13 mi, and the distance from centennial to the point where I think I turned around to be roughly 15 mi. If I'm right, then no incursion took place. If I'm wrong.... I should have continued circling over monument until I had formulated a complete plan for the return to base. I did feel a little pressure from 1 of my passenger, who wanted to get back in time for a dinner engagement. Whether or not an incursion took place, I do feel that I screwed up in not having proper situational awareness regarding the location of the class B. In the future, whenever I am ready to head back toward the class B, I will take the extra time to review class B particulars before heading back.

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Original NASA ASRS Text

Title: AN SMA FLYING IN DEN, CO, AIRSPACE IS UNCERTAIN OF THE LOCATION OF CLASS B AIRSPACE. PLT FEELS THERE MIGHT HAVE BEEN AN INTRUSION.

Narrative: I WAS OVER THE TOWN OF MONUMENT, CO, AT 10500 FT MSL AFTER HAVING FLOWN AROUND OVER THE HILLS TO THE W. I SET UP FOR A CRUISE DSCNT BACK TO MY BASE AT CENTENNIAL ARPT, TUNED, IDENTED, AND TURNED TOWARD THE CASSE NDB, AND THEN TUNED IN AND NOTED CENTENNIAL'S ATIS. A FEW MI S OF CASTLE ROCK, AT 10000 FT MSL AND A LITTLE E OF I25 (THE MAIN HWY), I GLANCED AT THE DEN TERMINAL CHART TO SEE WHERE THE CLASS B BEGAN, AND WAS HORRIFIED TO SEE THAT I WAS CLOSE TO PENETRATING THAT AIRSPACE, IF I HAD NOT DONE SO ALREADY. I HAD SOMEHOW THOUGHT THAT THE BOUNDARY WAS N OF CASTLE ROCK. I PULLED THE THROTTLE ALL THE WAY BACK AND BEGAN A 1000 FPM DSNDING L TURN BACK TO THE S. WHEN I WAS DOWN TO 8500 FT MSL, I TURNED BACK TO THE N AND CONTINUED TOWARD CENTENNIAL. AS I ARRIVED OVER THE POINT WHERE I HAD FIRST NOTICED THE POSSIBLE INCURSION, I NOTED THAT THE LORAN, WHICH IS NOT VERY ACCURATE, INDICATED THAT I WAS 18.3 MI FROM CENTENNIAL. ON MY DEN TERMINAL CHART I MEASURED THE DISTANCE FROM CENTENNIAL TO THE EDGE OF THE CLASS B (IN THE DIRECTION OF CASTLE ROCK) TO BE ROUGHLY 13 MI, AND THE DISTANCE FROM CENTENNIAL TO THE POINT WHERE I THINK I TURNED AROUND TO BE ROUGHLY 15 MI. IF I'M RIGHT, THEN NO INCURSION TOOK PLACE. IF I'M WRONG.... I SHOULD HAVE CONTINUED CIRCLING OVER MONUMENT UNTIL I HAD FORMULATED A COMPLETE PLAN FOR THE RETURN TO BASE. I DID FEEL A LITTLE PRESSURE FROM 1 OF MY PAX, WHO WANTED TO GET BACK IN TIME FOR A DINNER ENGAGEMENT. WHETHER OR NOT AN INCURSION TOOK PLACE, I DO FEEL THAT I SCREWED UP IN NOT HAVING PROPER SITUATIONAL AWARENESS REGARDING THE LOCATION OF THE CLASS B. IN THE FUTURE, WHENEVER I AM READY TO HEAD BACK TOWARD THE CLASS B, I WILL TAKE THE EXTRA TIME TO REVIEW CLASS B PARTICULARS BEFORE HDG BACK.

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.