Narrative:

I was a passenger on a business flight from stk to apa. Centennial airport is located under the den TCA, and it is possible that we inadvertently entered the TCA without a clearance. We departed stk VFR knowing that the en route visibility was good, but as the afternoon progressed, the thunderstorms would become difficult to circumnav. As we reached the halfway point, we could see thunderstorms developing to the west of our course. We were approximately 35 NM from apa at 6700 ft MSL. I noticed that there were rainshowers and thunderstorms from our 3 O'clock position to about our 1130 position. At that point I tuned in the apa ATIS and there was a thunderstorm over the airport and the temperature/dew point spread was prime for microburst activity. This fact was confirmed by moderate, localized dust storms to the west of our course. Due to past encounters with microburst activity, I was uncomfortable with our altitude and I asked the pilot (private pilot) to climb to 7500 ft MSL. The floor of the TCA at our position was at 8000 ft MSL, so this gave us a 500 ft buffer on altitude but we were close to a sector where the floor of the TCA was at 7000 ft MSL. I could see apa and the thunderstorm had passed to the east and left the airfield wet. We were approximately 8-10 NM to the east of buckley air national guard base when I called the tower for permission to transition the air traffic area to the southeast of the airfield. Tower advised me to contact den approach. I called approach and advised them that we were VFR to apa, and they gave me a squawk and said 'remain VFR.' the floor of the TCA at this point was at 7500 ft. Approximately 10 NM from apa I advised den that apa was in sight. An uneventful landing soon followed. Human factor: I have been flying large turning aircraft for a commuter airline for 2 1/2 yrs up to this point. I had forgotten what it was like to fly in a light single engine aircraft, especially when dealing with hazardous WX. This unfamiliarity caused me to focus mainly on WX avoidance and put the monitoring of our position lower on the list of priorities. The pilot I was flying with has not flown very much in co, and was not familiar with microbursts, or even what to look for. I should have insisted that we turn around. Next time I will!

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Original NASA ASRS Text

Title: PAX RPTS POSSIBLE TCA PENETRATION AS HE INSISTS PLT CLB TO AVOID POSSIBLE MICROBURST ACTIVITY.

Narrative: I WAS A PAX ON A BUSINESS FLT FROM STK TO APA. CENTENNIAL ARPT IS LOCATED UNDER THE DEN TCA, AND IT IS POSSIBLE THAT WE INADVERTENTLY ENTERED THE TCA WITHOUT A CLRNC. WE DEPARTED STK VFR KNOWING THAT THE ENRTE VISIBILITY WAS GOOD, BUT AS THE AFTERNOON PROGRESSED, THE TSTMS WOULD BECOME DIFFICULT TO CIRCUMNAV. AS WE REACHED THE HALFWAY POINT, WE COULD SEE TSTMS DEVELOPING TO THE W OF OUR COURSE. WE WERE APPROX 35 NM FROM APA AT 6700 FT MSL. I NOTICED THAT THERE WERE RAINSHOWERS AND TSTMS FROM OUR 3 O'CLOCK POS TO ABOUT OUR 1130 POS. AT THAT POINT I TUNED IN THE APA ATIS AND THERE WAS A TSTM OVER THE ARPT AND THE TEMP/DEW POINT SPREAD WAS PRIME FOR MICROBURST ACTIVITY. THIS FACT WAS CONFIRMED BY MODERATE, LOCALIZED DUST STORMS TO THE W OF OUR COURSE. DUE TO PAST ENCOUNTERS WITH MICROBURST ACTIVITY, I WAS UNCOMFORTABLE WITH OUR ALT AND I ASKED THE PLT (PRIVATE PLT) TO CLB TO 7500 FT MSL. THE FLOOR OF THE TCA AT OUR POS WAS AT 8000 FT MSL, SO THIS GAVE US A 500 FT BUFFER ON ALT BUT WE WERE CLOSE TO A SECTOR WHERE THE FLOOR OF THE TCA WAS AT 7000 FT MSL. I COULD SEE APA AND THE TSTM HAD PASSED TO THE E AND LEFT THE AIRFIELD WET. WE WERE APPROX 8-10 NM TO THE E OF BUCKLEY AIR NATIONAL GUARD BASE WHEN I CALLED THE TWR FOR PERMISSION TO TRANSITION THE ATA TO THE SE OF THE AIRFIELD. TWR ADVISED ME TO CONTACT DEN APCH. I CALLED APCH AND ADVISED THEM THAT WE WERE VFR TO APA, AND THEY GAVE ME A SQUAWK AND SAID 'REMAIN VFR.' THE FLOOR OF THE TCA AT THIS POINT WAS AT 7500 FT. APPROX 10 NM FROM APA I ADVISED DEN THAT APA WAS IN SIGHT. AN UNEVENTFUL LNDG SOON FOLLOWED. HUMAN FACTOR: I HAVE BEEN FLYING LARGE TURNING ACFT FOR A COMMUTER AIRLINE FOR 2 1/2 YRS UP TO THIS POINT. I HAD FORGOTTEN WHAT IT WAS LIKE TO FLY IN A LIGHT SINGLE ENG ACFT, ESPECIALLY WHEN DEALING WITH HAZARDOUS WX. THIS UNFAMILIARITY CAUSED ME TO FOCUS MAINLY ON WX AVOIDANCE AND PUT THE MONITORING OF OUR POS LOWER ON THE LIST OF PRIORITIES. THE PLT I WAS FLYING WITH HAS NOT FLOWN VERY MUCH IN CO, AND WAS NOT FAMILIAR WITH MICROBURSTS, OR EVEN WHAT TO LOOK FOR. I SHOULD HAVE INSISTED THAT WE TURN AROUND. NEXT TIME I WILL!

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.