Takeoff: Difference between revisions
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For propeller-driven aircraft, takeoff distance has been shown to be nearly proportional to wing loading (aircraft weight divided by wing area) and inversely proportional to the density ratio (actual density divided by sea level density), power-to-weight ratio, and the maximum takeoff lift coefficient. | For propeller-driven aircraft, takeoff distance has been shown to be nearly proportional to wing loading (aircraft weight divided by wing area) and inversely proportional to the density ratio (actual density divided by sea level density), power-to-weight ratio, and the maximum takeoff lift coefficient. | ||
== Effect of the High Compression STC and Sensenich Propeller == | == Effect of the High Compression STC, PowerFlow Exhaust, and Sensenich Propeller == | ||
As stated in [[Basic Engine and Propeller Performance]], the improvement in thrust power from the [[High Compression STC]] at speeds consistent with the takeoff roll is about 10%. Since takeoff distance is inversely proportional to power, takeoff distance will be reduced by about 10%. To determine the effect of exhaust and propeller improvements, those increments would have to be added to the engine curves as discussed in [[Basic Engine and Propeller Performance]] and new RPM equilibrium points found. But like the [[High Compression STC]], the result is more thrust power than the increase in brake power would indicate. | |||
== Use of Partial Flaps For Takeoff == | |||
Discussion about the use of partial flaps for takeoff can be found in [[Normal Procedures]]. While some claim that takeoff performance improves, measured takeoff distance performance actually varies per conditions. There is definitely a pitch attitude change beyond 1/3 flap deflection in an AA5x, that may feel more comfortable for some, and the use of flaps may improve angle-of-climb performance. There are only Ron Levy's and Bill Wilson's flight test flights that have been published in the AYA Star. | |||
Latest revision as of 20:41, 12 May 2014
Factors Influencing Ground Roll
For propeller-driven aircraft, takeoff distance has been shown to be nearly proportional to wing loading (aircraft weight divided by wing area) and inversely proportional to the density ratio (actual density divided by sea level density), power-to-weight ratio, and the maximum takeoff lift coefficient.
Effect of the High Compression STC, PowerFlow Exhaust, and Sensenich Propeller
As stated in Basic Engine and Propeller Performance, the improvement in thrust power from the High Compression STC at speeds consistent with the takeoff roll is about 10%. Since takeoff distance is inversely proportional to power, takeoff distance will be reduced by about 10%. To determine the effect of exhaust and propeller improvements, those increments would have to be added to the engine curves as discussed in Basic Engine and Propeller Performance and new RPM equilibrium points found. But like the High Compression STC, the result is more thrust power than the increase in brake power would indicate.
Use of Partial Flaps For Takeoff
Discussion about the use of partial flaps for takeoff can be found in Normal Procedures. While some claim that takeoff performance improves, measured takeoff distance performance actually varies per conditions. There is definitely a pitch attitude change beyond 1/3 flap deflection in an AA5x, that may feel more comfortable for some, and the use of flaps may improve angle-of-climb performance. There are only Ron Levy's and Bill Wilson's flight test flights that have been published in the AYA Star.
