Narrative:

I was simulating an engine failure by pulling the power on the small aircraft to an idle. I allowed the student to land at caldbeck airport, which I have done before. The landing was uneventful. The wind was 260 degree at 4 as report at rst which is about 15 mi north and is the nearest WX reporting. The runway, by the sectional is 3000', turf and is 18/36. To the north are power lines several hundred ft beyond the end of the runway. To the south are farm buildings. I tried to takeoff to the north and the power lines, mainly because rst was using runway 31. I looked as though we would never be off much before the power lines let alone get over them. I aborted the takeoff. I then taxied to the north end, put in 10 degree flaps for a soft field takeoff, which is by the 'book'. It's a little up hill to the south and I think/know this did not help for the takeoff to the south, however, the buildings didn't look as hard to get over. I used most of the runway to just get off the grass. I then started a turn to the west over the crops to clear the buildings. These are trees to the east of the south end of the runway. When the student and I got back to rst we refueled and I noted the amount of fuel pumped so I could calculate the gross weight at the time of takeoff. It was about 1550 pounds. I then calculated the density altitude and takeoff run. The temperature was 74 degree, the altimeter was 29.97. This gives a density altitude of 2500'. The small aircraft poh says it should take in 1074' of ground roll at an aircraft weight of 1600 pounds on dry grass. It was uphill and probably wet. I'm not sure the engine was up to PAR. It was turning good RPM but the small aircraft didn't seem to pull well. Also, the takeoff run 'by the book' is for a 'perfect' plane which, I don't think exists. I will surely remember this experience and will use much thought and care when calculating performance numbers.

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Original NASA ASRS Text

Title: FLT INSTRUCTOR AND STUDENT GAIN VALUABLE EXPERIENCE ABOUT THE EFFECT OF A SOFT RWY SURFACE ON TKOF PERFORMANCE.

Narrative: I WAS SIMULATING AN ENG FAILURE BY PULLING THE PWR ON THE SMA TO AN IDLE. I ALLOWED THE STUDENT TO LAND AT CALDBECK ARPT, WHICH I HAVE DONE BEFORE. THE LNDG WAS UNEVENTFUL. THE WIND WAS 260 DEG AT 4 AS RPT AT RST WHICH IS ABOUT 15 MI N AND IS THE NEAREST WX RPTING. THE RWY, BY THE SECTIONAL IS 3000', TURF AND IS 18/36. TO THE N ARE PWR LINES SEVERAL HUNDRED FT BEYOND THE END OF THE RWY. TO THE S ARE FARM BUILDINGS. I TRIED TO TKOF TO THE N AND THE PWR LINES, MAINLY BECAUSE RST WAS USING RWY 31. I LOOKED AS THOUGH WE WOULD NEVER BE OFF MUCH BEFORE THE PWR LINES LET ALONE GET OVER THEM. I ABORTED THE TKOF. I THEN TAXIED TO THE N END, PUT IN 10 DEG FLAPS FOR A SOFT FIELD TKOF, WHICH IS BY THE 'BOOK'. IT'S A LITTLE UP HILL TO THE S AND I THINK/KNOW THIS DID NOT HELP FOR THE TKOF TO THE S, HOWEVER, THE BUILDINGS DIDN'T LOOK AS HARD TO GET OVER. I USED MOST OF THE RWY TO JUST GET OFF THE GRASS. I THEN STARTED A TURN TO THE W OVER THE CROPS TO CLR THE BUILDINGS. THESE ARE TREES TO THE E OF THE S END OF THE RWY. WHEN THE STUDENT AND I GOT BACK TO RST WE REFUELED AND I NOTED THE AMOUNT OF FUEL PUMPED SO I COULD CALCULATE THE GROSS WT AT THE TIME OF TKOF. IT WAS ABOUT 1550 LBS. I THEN CALCULATED THE DENSITY ALT AND TKOF RUN. THE TEMP WAS 74 DEG, THE ALTIMETER WAS 29.97. THIS GIVES A DENSITY ALT OF 2500'. THE SMA POH SAYS IT SHOULD TAKE IN 1074' OF GND ROLL AT AN ACFT WT OF 1600 LBS ON DRY GRASS. IT WAS UPHILL AND PROBABLY WET. I'M NOT SURE THE ENG WAS UP TO PAR. IT WAS TURNING GOOD RPM BUT THE SMA DIDN'T SEEM TO PULL WELL. ALSO, THE TKOF RUN 'BY THE BOOK' IS FOR A 'PERFECT' PLANE WHICH, I DON'T THINK EXISTS. I WILL SURELY REMEMBER THIS EXPERIENCE AND WILL USE MUCH THOUGHT AND CARE WHEN CALCULATING PERFORMANCE NUMBERS.

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.