Narrative:

I was in a cessna 172-P on an IFR training flight. At the beginning of the flight, my cfii introduced me to DME arcs. This was my first flight in a cessna 172 since mar/94. I usually fly an american general tiger. Though I have not experienced vertigo in the tiger since my initial introduction to instrument training, I experienced it twice during the flight in the cessna 172. The terminal forecast for philadelphia northeast (pne) airport for XA00 zulu (XB00 am local) was 5000 scattered, 25000 scattered, surface winds out of 210 degrees at 10 KTS, visibility greater than 7 mi with an occasional visibility of 5 mi in haze. For the most part actual conditions matched the forecast. We were doing the VOR instrument approach to doylestown (N88) using the 240 degree radial from the solberg (sbj) VOR. I did not slow to approach speed and descend to 2000 ft MSL until I was nearly at groom intersection (340 degree radial from the yardley (ard) VOR. After some prompting from my cfii, I slowed and descended. We were about 2 mi out from doylestown when my cfii asked me if I wanted to pull up or continue to fly into the ground. At my cfii's comment, I immediately applied full power and climbed to 1020 ft which is the minimum descent altitude (MDA) for that approach. Shortly thereafter, my cfii told me to remove my foggles. I misread the altimeter, thinking it was 1600 ft MSL when it was really 600 ft MSL. The terrain elevation in that area is approximately 400 ft MSL, so we were only about 200 ft AGL. While the area is not densely populated, there are residences in the area and I could have come within 500 ft of them. However, I am not completely certain of this since I was still under the hood. My cfii and I discussed my mistake during post flight. This is the first time I have ever misread an altimeter. I think the following factors contributed to it: instances of vertigo earlier in the flight, unfamiliarity with the cessna cockpit relative to the tiger, getting behind the airplane by not descending and slowing prior to groom intersection, and poor instrument scan during the final phases of the approach.

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Original NASA ASRS Text

Title: ON PRACTICE VOR APCH INST STUDENT CONTINUES BELOW PUB ALT BY 1000 FT.

Narrative: I WAS IN A CESSNA 172-P ON AN IFR TRAINING FLT. AT THE BEGINNING OF THE FLT, MY CFII INTRODUCED ME TO DME ARCS. THIS WAS MY FIRST FLT IN A CESSNA 172 SINCE MAR/94. I USUALLY FLY AN AMERICAN GENERAL TIGER. THOUGH I HAVE NOT EXPERIENCED VERTIGO IN THE TIGER SINCE MY INITIAL INTRODUCTION TO INST TRAINING, I EXPERIENCED IT TWICE DURING THE FLT IN THE CESSNA 172. THE TERMINAL FORECAST FOR PHILADELPHIA NE (PNE) ARPT FOR XA00 ZULU (XB00 AM LCL) WAS 5000 SCATTERED, 25000 SCATTERED, SURFACE WINDS OUT OF 210 DEGS AT 10 KTS, VISIBILITY GREATER THAN 7 MI WITH AN OCCASIONAL VISIBILITY OF 5 MI IN HAZE. FOR THE MOST PART ACTUAL CONDITIONS MATCHED THE FORECAST. WE WERE DOING THE VOR INST APCH TO DOYLESTOWN (N88) USING THE 240 DEG RADIAL FROM THE SOLBERG (SBJ) VOR. I DID NOT SLOW TO APCH SPD AND DSND TO 2000 FT MSL UNTIL I WAS NEARLY AT GROOM INTXN (340 DEG RADIAL FROM THE YARDLEY (ARD) VOR. AFTER SOME PROMPTING FROM MY CFII, I SLOWED AND DSNDED. WE WERE ABOUT 2 MI OUT FROM DOYLESTOWN WHEN MY CFII ASKED ME IF I WANTED TO PULL UP OR CONTINUE TO FLY INTO THE GND. AT MY CFII'S COMMENT, I IMMEDIATELY APPLIED FULL PWR AND CLBED TO 1020 FT WHICH IS THE MINIMUM DSCNT ALT (MDA) FOR THAT APCH. SHORTLY THEREAFTER, MY CFII TOLD ME TO REMOVE MY FOGGLES. I MISREAD THE ALTIMETER, THINKING IT WAS 1600 FT MSL WHEN IT WAS REALLY 600 FT MSL. THE TERRAIN ELEVATION IN THAT AREA IS APPROX 400 FT MSL, SO WE WERE ONLY ABOUT 200 FT AGL. WHILE THE AREA IS NOT DENSELY POPULATED, THERE ARE RESIDENCES IN THE AREA AND I COULD HAVE COME WITHIN 500 FT OF THEM. HOWEVER, I AM NOT COMPLETELY CERTAIN OF THIS SINCE I WAS STILL UNDER THE HOOD. MY CFII AND I DISCUSSED MY MISTAKE DURING POST FLT. THIS IS THE FIRST TIME I HAVE EVER MISREAD AN ALTIMETER. I THINK THE FOLLOWING FACTORS CONTRIBUTED TO IT: INSTANCES OF VERTIGO EARLIER IN THE FLT, UNFAMILIARITY WITH THE CESSNA COCKPIT RELATIVE TO THE TIGER, GETTING BEHIND THE AIRPLANE BY NOT DSNDING AND SLOWING PRIOR TO GROOM INTXN, AND POOR INST SCAN DURING THE FINAL PHASES OF THE APCH.

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.