Originally Posted By: Dave W
You didn't say what technique are you using on the pavement? If you are doing a "Soft Field Takeoff" with the nose really high then the take-off run will be longer even though you lift off at a slower speed. The STOL guys on grass don't do "Soft Field" takeoffs.

If you are doing a normal short field takeoff and not meeting the book numbers then either your engine is tired, or you have a cruise prop, or your airspeed is slightly off causing a late rotation.

Although you should test it early in the morning as hot pavement will hurt performance.


I am doing a no flaps, slightly tail low T/O. Was trying to use the book suggestion of no flaps for the T/O calculation since that is what they are based on. I have wondered about my ASI and its accuracy to be honest, so I have started trying to pull it off at lower airspeeds than 60 and it will get off the ground at around 55ish at close to 900 ft, but it is definitely more sluggish in the control inputs. I am getting G5s here in 2-3 weeks so will be interesting to see what they say compared to the ASI. Personally I suspect it is a combination of tired engine, perhaps ASI being slightly off and less than ideal pilot technique. At least it gives me some real world expectations of performance rather than just using the book numbers. I can give it a "fudge factor" adjustment to be safer now that i seem somewhat consistent in distance.