Narrative:

I was flying with my private pilot student (approximately 15 hours) to ftg to do touch and go. We were told to enter the right base runway 8. I was aware that the denver class bravo airspace is fairly close to the approach end of the runway. That said; I told my student to keep his base in tight. It has been years since I have flown to ftg; but from my recollection the class bravo airspace started at a set of power lines that ran across the ground off to the west. I told my student to keep us significantly inside of that to remain clear of the bravo. On the base I noticed a road also just off the west end of the runway that runs north/south. I looked at the GPS and it appeared we were very near to the class B airspace. Our airplane was displayed just inside the class bravo divider; with some of the aircraft on the line. After the touch-and-go I queried tower to ask whether the class bravo started at the power lines or at this road. He responded that the class bravo airspace began at this road (imboden rd.). While I am fairly sure that we remained just inside of imboden rd. (In the class delta) on our first base; I was still nonetheless caught off guard by how near this airspace is to the approach end of runway 8 and I believe it is smart to fill out a NASA report for this instance; as I know I'm not the only one to have been in this situation. Ultimately on the follow-up patterns I had the student keep his base turn in even closer given this proximity to the class bravo airspace. My unfamiliarity with the airspace and reliance on an experience from several years ago took me far closer to class bravo airspace than I care to be without clearance. In the future I would perhaps ask another instructor who is more familiar with the airspace before going to an unfamiliar airport.

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Original NASA ASRS Text

Title: SR22 Instructor pilot reported encroaching (or nearly encroaching) on Class B airspace while in the pattern at FTG.

Narrative: I was flying with my private pilot student (approximately 15 hours) to FTG to do touch and go. We were told to enter the right base RWY 8. I was aware that the Denver Class Bravo airspace is fairly close to the approach end of the runway. That said; I told my student to keep his base in tight. It has been years since I have flown to FTG; but from my recollection the Class Bravo airspace started at a set of power lines that ran across the ground off to the West. I told my student to keep us significantly inside of that to remain clear of the Bravo. On the base I noticed a road also just off the West end of the runway that runs North/South. I looked at the GPS and it appeared we were very near to the Class B airspace. Our airplane was displayed just inside the class Bravo divider; with some of the aircraft on the line. After the touch-and-go I queried tower to ask whether the class Bravo started at the power lines or at this road. He responded that the class Bravo airspace began at this road (Imboden Rd.). While I am fairly sure that we remained just inside of Imboden Rd. (in the class Delta) on our first base; I was still nonetheless caught off guard by how near this airspace is to the approach end of RWY 8 and I believe it is smart to fill out a NASA report for this instance; as I know I'm not the only one to have been in this situation. Ultimately on the follow-up patterns I had the student keep his base turn in even closer given this proximity to the class Bravo airspace. My unfamiliarity with the airspace and reliance on an experience from several years ago took me far closer to class Bravo airspace than I care to be without clearance. In the future I would perhaps ask another instructor who is more familiar with the airspace before going to an unfamiliar airport.

Data retrieved from NASA's ASRS site 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.