Narrative:

This event occurred during takeoff on runway 21. After adding full power; I pushed the stick forward to attain takeoff attitude; the aircraft rotated at a greater than normal rate. I attempted to counteract the rapid rotation; but was unable. When it became apparent that the propeller may strike the runway; I pulled the throttle to idle and shut down the engine. The nose continued to rotate down and the propeller struck the runway. Contributing factors: 1) although AWOS was reporting calm winds; I; afterwards; noticed the windsock to be showing winds gusty from the right rear quarter of the aircraft when in the takeoff position. I also noticed some dust devils in the area. I believe that winds were a significant contributing factor in this event. 2) this aircraft has a lycoming 4 cylinder engine rated at 160HP. I believe this aircraft was originally equipped with a 100HP engine. I suspect this engine/flight control combination has the ability to affect pitch control greater than on the original PA12 100HP version. Not that this is bad; but extra care must be taken in certain regimes. 3) afterwards; I noticed that the takeoff trim indicator was in a more than normal nose down position than I was used to; which may have contributed to the over rotation. 4) I weigh 180 pounds and was flying solo (front seat); with no other passenger or baggage behind me; which I believe would result in a more forward center of gravity. Corrective actions: 1) don't rely solely on AWOS for WX information. Use visual cues for wind information; such as windsocks; flags; dust; dust devils; etc. 2) be aware of how load configns affect center of gravity and pitch response. 3) ensure pitch trim is appropriate for conditions. 4) I'm not an aerodynamic engineer; but be more attentive to different airframe/power plant configns.

Related reports:

Google
 

Original NASA ASRS Text

Title: A PA-12 PILOT REPORTS STRIKING THE PROP ON THE RUNWAY ON TAKEOFF ROLL.

Narrative: THIS EVENT OCCURRED DURING TKOF ON RWY 21. AFTER ADDING FULL PWR; I PUSHED THE STICK FORWARD TO ATTAIN TKOF ATTITUDE; THE ACFT ROTATED AT A GREATER THAN NORMAL RATE. I ATTEMPTED TO COUNTERACT THE RAPID ROTATION; BUT WAS UNABLE. WHEN IT BECAME APPARENT THAT THE PROP MAY STRIKE THE RWY; I PULLED THE THROTTLE TO IDLE AND SHUT DOWN THE ENG. THE NOSE CONTINUED TO ROTATE DOWN AND THE PROP STRUCK THE RWY. CONTRIBUTING FACTORS: 1) ALTHOUGH AWOS WAS RPTING CALM WINDS; I; AFTERWARDS; NOTICED THE WINDSOCK TO BE SHOWING WINDS GUSTY FROM THE R REAR QUARTER OF THE ACFT WHEN IN THE TKOF POS. I ALSO NOTICED SOME DUST DEVILS IN THE AREA. I BELIEVE THAT WINDS WERE A SIGNIFICANT CONTRIBUTING FACTOR IN THIS EVENT. 2) THIS ACFT HAS A LYCOMING 4 CYLINDER ENG RATED AT 160HP. I BELIEVE THIS ACFT WAS ORIGINALLY EQUIPPED WITH A 100HP ENG. I SUSPECT THIS ENG/FLT CTL COMBINATION HAS THE ABILITY TO AFFECT PITCH CTL GREATER THAN ON THE ORIGINAL PA12 100HP VERSION. NOT THAT THIS IS BAD; BUT EXTRA CARE MUST BE TAKEN IN CERTAIN REGIMES. 3) AFTERWARDS; I NOTICED THAT THE TKOF TRIM INDICATOR WAS IN A MORE THAN NORMAL NOSE DOWN POS THAN I WAS USED TO; WHICH MAY HAVE CONTRIBUTED TO THE OVER ROTATION. 4) I WEIGH 180 LBS AND WAS FLYING SOLO (FRONT SEAT); WITH NO OTHER PAX OR BAGGAGE BEHIND ME; WHICH I BELIEVE WOULD RESULT IN A MORE FORWARD CTR OF GRAVITY. CORRECTIVE ACTIONS: 1) DON'T RELY SOLELY ON AWOS FOR WX INFO. USE VISUAL CUES FOR WIND INFO; SUCH AS WINDSOCKS; FLAGS; DUST; DUST DEVILS; ETC. 2) BE AWARE OF HOW LOAD CONFIGNS AFFECT CTR OF GRAVITY AND PITCH RESPONSE. 3) ENSURE PITCH TRIM IS APPROPRIATE FOR CONDITIONS. 4) I'M NOT AN AERODYNAMIC ENGINEER; BUT BE MORE ATTENTIVE TO DIFFERENT AIRFRAME/PWR PLANT CONFIGNS.

Data retrieved from NASA's ASRS site as of January 2009 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.