Small aircraft on practice short field takeoff uses three-fourths of runway and not achieving airspe...

Attributes
ACN	162724
Time
Date	199011
Day	Mon
Local Time Of Day	0601 To 1200
Place
Locale Reference	airport : c84
State Reference	IA
Altitude	agl bound lower : 0 agl bound upper : 0
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Operator	general aviation : instructional
Make Model Name	Small Aircraft, Low Wing, 1 Eng, Fixed Gear
Flight Phase	climbout : takeoff
Flight Plan	None
Person 1
Affiliation	Other
Function	instruction : instructor
Qualification	pilot : commercial pilot : cfi pilot : instrument
Experience	flight time last 90 days : 55 flight time total : 365 flight time type : 150
ASRS Report	162724
Person 2
Affiliation	Other
Function	instruction : trainee
Qualification	pilot : student
Events
Anomaly	other anomaly other anomaly other
Independent Detector	other flight crewa
Resolutory Action	none taken : unable
Consequence	other
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

The student was going to demonstrate a short field over an obstacle takeoff. We taxied to the very end of runway, did our runup as per the checklist, applied 2 notches flaps, full nose wheel. As we approached the end of the runway, approximately 3/4 the way down, the airspeed indicator had not yet reached 40 KTS. I reached up and pulled the throttle to idle and applied the brakes. The aircraft crossed the road, went through a fence and came to rest in a field, after having turned almost 180 degrees. There were 2 persons on board--1 weighing 180#, the other 150#. There were approximately 35 gals of fuel in the tanks. Aircraft was an small aircraft. Contributing factors: runway was a grass strip 1300' long. Runway was not really soft, grass was 6-7' tall. I now honestly believe that had I left the throttle, the aircraft would have taken off, but with little room to spare. The aircraft would have been about 400# under gross weight. In the end, looking at performance charts, etc, we just didn't leave any room for error or variables. No way out.

Original NASA ASRS Text

Title: SMA ON PRACTICE SHORT FIELD TKOF USES THREE-FOURTHS OF RWY AND NOT ACHIEVING AIRSPEED REQUIRED. INSTRUCTOR ABORTS TKOF AND ACFT RUNS OFF END OF RWY.

Narrative: THE STUDENT WAS GOING TO DEMONSTRATE A SHORT FIELD OVER AN OBSTACLE TKOF. WE TAXIED TO THE VERY END OF RWY, DID OUR RUNUP AS PER THE CHKLIST, APPLIED 2 NOTCHES FLAPS, FULL NOSE WHEEL. AS WE APCHED THE END OF THE RWY, APPROX 3/4 THE WAY DOWN, THE AIRSPD INDICATOR HAD NOT YET REACHED 40 KTS. I REACHED UP AND PULLED THE THROTTLE TO IDLE AND APPLIED THE BRAKES. THE ACFT CROSSED THE ROAD, WENT THROUGH A FENCE AND CAME TO REST IN A FIELD, AFTER HAVING TURNED ALMOST 180 DEGS. THERE WERE 2 PERSONS ON BOARD--1 WEIGHING 180#, THE OTHER 150#. THERE WERE APPROX 35 GALS OF FUEL IN THE TANKS. ACFT WAS AN SMA. CONTRIBUTING FACTORS: RWY WAS A GRASS STRIP 1300' LONG. RWY WAS NOT REALLY SOFT, GRASS WAS 6-7' TALL. I NOW HONESTLY BELIEVE THAT HAD I LEFT THE THROTTLE, THE ACFT WOULD HAVE TAKEN OFF, BUT WITH LITTLE ROOM TO SPARE. THE ACFT WOULD HAVE BEEN ABOUT 400# UNDER GROSS WT. IN THE END, LOOKING AT PERFORMANCE CHARTS, ETC, WE JUST DIDN'T LEAVE ANY ROOM FOR ERROR OR VARIABLES. NO WAY OUT.

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.

Small aircraft on practice short field takeoff uses three-fourths of runway and not achieving airspeed required. Instructor aborts takeoff and aircraft runs off end of runway.