Takeoff - Revision history

BillWilson: /* Use of Partial Flaps For Takeoff */

2014-05-12T20:41:54Z

Use of Partial Flaps For Takeoff

← Older revision		Revision as of 20:41, 12 May 2014
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	== Use of Partial Flaps For Takeoff ==		== 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 ~~did not seem to improve~~. There is definitely a pitch attitude change that may feel more comfortable for some ~~leading them to claim better performance~~, and the use of flaps may improve angle-of-climb performance ~~tricking the eye into thinking rate-of-climb is improved~~. There is only Ron Levy's test flights.		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.

Jbowman90 at 20:55, 26 January 2008

2008-01-26T20:55:11Z

← Older revision		Revision as of 20:55, 26 January 2008
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	== Effect of the High Compression STC, PowerFlow Exhaust, 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 ~~takeoff distance~~, 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.		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 ==		== 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 did not seem to improve. There is definitely a pitch attitude change that may feel more comfortable for some leading them to claim better performance, and the use of flaps may improve angle-of-climb performance tricking the eye into thinking rate-of-climb is improved. There is only Ron Levy's test flights.		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 did not seem to improve. There is definitely a pitch attitude change that may feel more comfortable for some leading them to claim better performance, and the use of flaps may improve angle-of-climb performance tricking the eye into thinking rate-of-climb is improved. There is only Ron Levy's test flights.

Jbowman90 at 02:55, 22 January 2008

2008-01-22T02:55:16Z

← Older revision		Revision as of 02:55, 22 January 2008
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	== Use of Partial Flaps For Takeoff ==		== 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 did not seem to improve. There is definitely a pitch attitude change that may feel more comfortable for some leading them to claim better performance, and the use of flaps may improve angle-of-climb performance tricking the eye into thinking rate-of-climb is improved. There is only Ron Levy's test flights.		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 did not seem to improve. There is definitely a pitch attitude change that may feel more comfortable for some leading them to claim better performance, and the use of flaps may improve angle-of-climb performance tricking the eye into thinking rate-of-climb is improved. There is only Ron Levy's test flights.

Jbowman90: Add short discussion on partial flap takeoff performance and link to normal procedures discussion

2008-01-22T02:54:59Z

Add short discussion on partial flap takeoff performance and link to normal procedures discussion

← Older revision		Revision as of 02:54, 22 January 2008
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	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 takeoff distance, 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.		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 takeoff distance, 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 did not seem to improve. There is definitely a pitch attitude change that may feel more comfortable for some leading them to claim better performance, and the use of flaps may improve angle-of-climb performance tricking the eye into thinking rate-of-climb is improved. There is only Ron Levy's test flights.

Jbowman90: Fixed takeoff discussion to be consistent with engine and propeller discussion elsewhere

2008-01-22T02:48:00Z

Fixed takeoff discussion to be consistent with engine and propeller discussion elsewhere

← Older revision		Revision as of 02:48, 22 January 2008
Line 5:		Line 5:
	== Effect of the High Compression STC, PowerFlow Exhaust, and Sensenich Propeller ==		== Effect of the High Compression STC, PowerFlow Exhaust, and Sensenich Propeller ==

	'''Note: The fundamentals of the discussion below are correct. However, after researching actual propeller data, it may appear that the propeller efficiency ''decreases'' with increasing RPM for the same airspeed. If this is the case, more analysis needs to be done to understand why some are claiming the effect of the extra 7.5 HP is disproportionate in ~~favor of more performance. Please be patient while this issue is being researched.'''~~		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 takeoff distance, 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.

	~~The~~ [[~~High Compression STC]] for the O-320 engines adds approximately 7.5 brake horsepower. Because the additional brake power allows the propeller to be turned faster~~ and ~~most Grummans have cruise propellers, the effect of the higher rotation speed is that the [http://en.wikipedia.org/wiki/~~Propeller ~~propeller~~] ~~now operates more [http://en.wikipedia.org/wiki/Propeller#Aviation efficiently~~]~~. This means that more of~~ the original 150 HP from the stock engine makes it into the air as thrust. It is also believed that the Sensenich propeller is more efficient by design than the original McCauley propeller. Therefore the combination of the High Compression STC and Sensenich propeller allows significantly more power to be converted to thrust than the stock configuration.

	~~It can be shown that the reduction~~ in takeoff distance is a combination of two factors. The first is due to raw [http://en.wikipedia.org/wiki/Propeller#Aviation propeller efficiency] improvement. More efficiency means more of the original 150HP makes it into the air as thrust. The reduction in takeoff distance due to the first factor is approximately the percent increase in propeller efficiency. The second factor also contains the propeller efficiency improvement but also the effect of the additional brake power from the [[High Compression STC]]~~. More specifically,~~ the ~~second factor~~ is ~~the product of the ratio of propeller efficiencies and the ratio of the extra brake power (7.5 HP) to the original brake power (150 HP) of the engine.~~

	~~[[Image:takeoff_distance_improvement.png\|thumb\|300 px\|Takeoff Distance Reduction]]~~

	~~Although actual propeller efficiencies numbers are not available, assume an overall~~ 10% ~~improvement~~. ~~Then the first factor gives an approximate reduction in~~ takeoff distance ~~of 10%~~, ~~and the second factor gives a reduction in~~ takeoff distance of about 5% ~~( (1 + 0~~.~~1)*7.5/150 ). The~~ effect ~~that~~ the [[~~High Compression STC~~]] ~~has on propeller efficiency is two (2) times the effect of the additional power from the High Compression STC. For a 20% improvement in efficiency, these factors are 20%~~ and ~~6% respectively~~. ~~So the effect that~~ the High Compression STC ~~has on propeller efficiency is now three (3) times the effect of the additional power from the High Compression STC! For takeoff distance~~, the ~~main impact of the High Compression STC~~ is ~~to allow~~ more ~~of the original 150HP to be converted into~~ thrust~~. The secondary impact is~~ the ~~additional 7.5 HP.~~

	~~The figure on the right illustrates the percent reduction~~ in ~~takeoff distance for any combination of propeller efficiency. Shown on the plot are the lines where the propeller efficiency improvement is 5% and 10%~~.

Jbowman90: Added cautionary note

2007-12-25T15:38:51Z

Added cautionary note

← Older revision		Revision as of 15:38, 25 December 2007
Line 4:		Line 4:

	== Effect of the High Compression STC, PowerFlow Exhaust, and Sensenich Propeller ==		== Effect of the High Compression STC, PowerFlow Exhaust, and Sensenich Propeller ==

			'''Note: The fundamentals of the discussion below are correct. However, after researching actual propeller data, it may appear that the propeller efficiency ''decreases'' with increasing RPM for the same airspeed. If this is the case, more analysis needs to be done to understand why some are claiming the effect of the extra 7.5 HP is disproportionate in favor of more performance. Please be patient while this issue is being researched.'''

	The [[High Compression STC]] for the O-320 engines adds approximately 7.5 brake horsepower. Because the additional brake power allows the propeller to be turned faster and most Grummans have cruise propellers, the effect of the higher rotation speed is that the [http://en.wikipedia.org/wiki/Propeller propeller] now operates more [http://en.wikipedia.org/wiki/Propeller#Aviation efficiently]. This means that more of the original 150 HP from the stock engine makes it into the air as thrust. It is also believed that the Sensenich propeller is more efficient by design than the original McCauley propeller. Therefore the combination of the High Compression STC and Sensenich propeller allows significantly more power to be converted to thrust than the stock configuration.		The [[High Compression STC]] for the O-320 engines adds approximately 7.5 brake horsepower. Because the additional brake power allows the propeller to be turned faster and most Grummans have cruise propellers, the effect of the higher rotation speed is that the [http://en.wikipedia.org/wiki/Propeller propeller] now operates more [http://en.wikipedia.org/wiki/Propeller#Aviation efficiently]. This means that more of the original 150 HP from the stock engine makes it into the air as thrust. It is also believed that the Sensenich propeller is more efficient by design than the original McCauley propeller. Therefore the combination of the High Compression STC and Sensenich propeller allows significantly more power to be converted to thrust than the stock configuration.

Jbowman90 at 16:55, 24 December 2007

2007-12-24T16:55:26Z

← Older revision		Revision as of 16:55, 24 December 2007
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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 ==

	The [[High Compression STC]] for the O-320 engines adds approximately 7.5 brake horsepower. Because the additional brake power allows the propeller to be turned faster and most Grummans have cruise propellers, the effect of the higher rotation speed is that the [http://en.wikipedia.org/wiki/Propeller propeller] now operates more [http://en.wikipedia.org/wiki/Propeller#Aviation efficiently]. This means that more of the original 150 HP from the stock engine makes it into the air as thrust. It is also believed that the Sensenich propeller is more efficient by design than the original McCauley propeller. Therefore the combination of the High Compression STC and Sensenich propeller allows significantly more power to be converted to thrust than the stock configuration.		The [[High Compression STC]] for the O-320 engines adds approximately 7.5 brake horsepower. Because the additional brake power allows the propeller to be turned faster and most Grummans have cruise propellers, the effect of the higher rotation speed is that the [http://en.wikipedia.org/wiki/Propeller propeller] now operates more [http://en.wikipedia.org/wiki/Propeller#Aviation efficiently]. This means that more of the original 150 HP from the stock engine makes it into the air as thrust. It is also believed that the Sensenich propeller is more efficient by design than the original McCauley propeller. Therefore the combination of the High Compression STC and Sensenich propeller allows significantly more power to be converted to thrust than the stock configuration.

Jbowman90: Linked to the Wikipedia pages on propellers and propeller efficiency

2007-12-24T16:46:01Z

Linked to the Wikipedia pages on propellers and propeller efficiency

← Older revision		Revision as of 16:46, 24 December 2007
Line 5:		Line 5:
	== Effect of the High Compression STC and Sensenich Propeller ==		== Effect of the High Compression STC and Sensenich Propeller ==

	The [[High Compression STC]] for the O-320 engines adds approximately 7.5 brake horsepower. Because the additional brake power allows the propeller to be turned faster and most Grummans have cruise propellers, the effect of the higher rotation speed is that the propeller now operates more efficiently. This means that more of the original 150 HP from the stock engine makes it into the air as thrust. It is also believed that the Sensenich propeller is more efficient by design than the original McCauley propeller. Therefore the combination of the [[High Compression STC]] and Sensenich propeller allows significantly more power to be converted to thrust than the stock configuration.		The [[High Compression STC]] for the O-320 engines adds approximately 7.5 brake horsepower. Because the additional brake power allows the propeller to be turned faster and most Grummans have cruise propellers, the effect of the higher rotation speed is that the [http://en.wikipedia.org/wiki/Propeller propeller] now operates more [http://en.wikipedia.org/wiki/Propeller#Aviation efficiently]. This means that more of the original 150 HP from the stock engine makes it into the air as thrust. It is also believed that the Sensenich propeller is more efficient by design than the original McCauley propeller. Therefore the combination of the High Compression STC and Sensenich propeller allows significantly more power to be converted to thrust than the stock configuration.

	It can be shown that the reduction in takeoff distance is a combination of two factors. The first is due to raw propeller efficiency improvement. More efficiency means more of the original 150HP makes it into the air as thrust. The reduction in takeoff distance due to the first factor is approximately the percent increase in propeller efficiency. The second factor also contains propeller efficiency improvement but also the effect of the additional brake power from the [[High Compression STC]]. More specifically, the second factor is the product of the ratio of propeller efficiencies and the ratio of the extra brake power (7.5 HP) to the original brake power (150 HP) of the engine.		It can be shown that the reduction in takeoff distance is a combination of two factors. The first is due to raw [http://en.wikipedia.org/wiki/Propeller#Aviation propeller efficiency] improvement. More efficiency means more of the original 150HP makes it into the air as thrust. The reduction in takeoff distance due to the first factor is approximately the percent increase in propeller efficiency. The second factor also contains the propeller efficiency improvement but also the effect of the additional brake power from the [[High Compression STC]]. More specifically, the second factor is the product of the ratio of propeller efficiencies and the ratio of the extra brake power (7.5 HP) to the original brake power (150 HP) of the engine.

	[[Image:takeoff_distance_improvement.png\|thumb\|300 px\|Takeoff Distance Reduction]]		[[Image:takeoff_distance_improvement.png\|thumb\|300 px\|Takeoff Distance Reduction]]

	Although actual propeller efficiencies numbers are not available, assume an overall 10% improvement. Then the first factor gives an approximate reduction in takeoff distance of 10%, and the second factor gives a reduction in takeoff distance of about 5% ( (1 + 0.1)*7.5/150 ). The effect that the [[High Compression STC]] has on propeller efficiency is two (2) times the effect of the additional power from the [[High Compression STC]]. For a 20% improvement in efficiency, these factors are 20% and 6% respectively. So the effect that the [[High Compression STC]] has on propeller efficiency is now three (3) times the effect of the additional power from the [[High Compression STC]]! For takeoff distance, the main impact of the [[High Compression STC]] is to allow more of the original 150HP to be converted into thrust. The secondary impact is the additional 7.5 HP.		Although actual propeller efficiencies numbers are not available, assume an overall 10% improvement. Then the first factor gives an approximate reduction in takeoff distance of 10%, and the second factor gives a reduction in takeoff distance of about 5% ( (1 + 0.1)*7.5/150 ). The effect that the [[High Compression STC]] has on propeller efficiency is two (2) times the effect of the additional power from the High Compression STC. For a 20% improvement in efficiency, these factors are 20% and 6% respectively. So the effect that the High Compression STC has on propeller efficiency is now three (3) times the effect of the additional power from the High Compression STC! For takeoff distance, the main impact of the High Compression STC is to allow more of the original 150HP to be converted into thrust. The secondary impact is the additional 7.5 HP.

	The figure on the right illustrates the percent reduction in takeoff distance for any combination of propeller efficiency. Shown on the plot are the lines where the propeller efficiency improvement is 5% and 10%.		The figure on the right illustrates the percent reduction in takeoff distance for any combination of propeller efficiency. Shown on the plot are the lines where the propeller efficiency improvement is 5% and 10%.

Jbowman90: Added links to the currently non-existing High Compression STC page

2007-12-24T16:11:15Z

Added links to the currently non-existing High Compression STC page

← Older revision		Revision as of 16:11, 24 December 2007
Line 5:		Line 5:
	== Effect of the High Compression STC and Sensenich Propeller ==		== Effect of the High Compression STC and Sensenich Propeller ==

	The High Compression STC for the O-320 engines adds approximately 7.5 brake horsepower. Because the additional brake power allows the propeller to be turned faster and most Grummans have cruise propellers, the effect of the higher rotation speed is that the propeller now operates more efficiently. This means that more of the original 150 HP from the stock engine makes it into the air as thrust. It is also believed that the Sensenich propeller is more efficient by design than the original McCauley propeller. Therefore the combination of the High Compression STC and Sensenich propeller allows significantly more power to be converted to thrust than the stock configuration.		The [[High Compression STC]] for the O-320 engines adds approximately 7.5 brake horsepower. Because the additional brake power allows the propeller to be turned faster and most Grummans have cruise propellers, the effect of the higher rotation speed is that the propeller now operates more efficiently. This means that more of the original 150 HP from the stock engine makes it into the air as thrust. It is also believed that the Sensenich propeller is more efficient by design than the original McCauley propeller. Therefore the combination of the [[High Compression STC]] and Sensenich propeller allows significantly more power to be converted to thrust than the stock configuration.

	It can be shown that the reduction in takeoff distance is a combination of two factors. The first is due to raw propeller efficiency improvement. More efficiency means more of the original 150HP makes it into the air as thrust. The reduction in takeoff distance due to the first factor is approximately the percent increase in propeller efficiency. The second factor also contains propeller efficiency improvement but also the effect of the additional brake power from the High Compression STC. More specifically, the second factor is the product of the ratio of propeller efficiencies and the ratio of the extra brake power (7.5 HP) to the original brake power (150 HP) of the engine.		It can be shown that the reduction in takeoff distance is a combination of two factors. The first is due to raw propeller efficiency improvement. More efficiency means more of the original 150HP makes it into the air as thrust. The reduction in takeoff distance due to the first factor is approximately the percent increase in propeller efficiency. The second factor also contains propeller efficiency improvement but also the effect of the additional brake power from the [[High Compression STC]]. More specifically, the second factor is the product of the ratio of propeller efficiencies and the ratio of the extra brake power (7.5 HP) to the original brake power (150 HP) of the engine.

	[[Image:takeoff_distance_improvement.png\|thumb\|300 px\|Takeoff Distance Reduction]]		[[Image:takeoff_distance_improvement.png\|thumb\|300 px\|Takeoff Distance Reduction]]

	Although actual propeller efficiencies numbers are not available, assume an overall 10% improvement. Then the first factor gives an approximate reduction in takeoff distance of 10%, and the second factor gives a reduction in takeoff distance of about 5% ( (1 + 0.1)*7.5/150 ). The effect that the High Compression STC has on propeller efficiency is two (2) times the effect of the additional power from the High Compression STC. For a 20% improvement in efficiency, these factors are 20% and 6% respectively. So the effect that the High Compression STC has on propeller efficiency is now three (3) times the effect of the additional power from the High Compression STC! For takeoff distance, the main impact of the High Compression STC is to allow more of the original 150HP to be converted into thrust. The secondary impact is the additional 7.5 HP.		Although actual propeller efficiencies numbers are not available, assume an overall 10% improvement. Then the first factor gives an approximate reduction in takeoff distance of 10%, and the second factor gives a reduction in takeoff distance of about 5% ( (1 + 0.1)*7.5/150 ). The effect that the [[High Compression STC]] has on propeller efficiency is two (2) times the effect of the additional power from the [[High Compression STC]]. For a 20% improvement in efficiency, these factors are 20% and 6% respectively. So the effect that the [[High Compression STC]] has on propeller efficiency is now three (3) times the effect of the additional power from the [[High Compression STC]]! For takeoff distance, the main impact of the [[High Compression STC]] is to allow more of the original 150HP to be converted into thrust. The secondary impact is the additional 7.5 HP.

	The figure on the right illustrates the percent reduction in takeoff distance for any combination of propeller efficiency. Shown on the plot are the lines where the propeller efficiency improvement is 5% and 10%.		The figure on the right illustrates the percent reduction in takeoff distance for any combination of propeller efficiency. Shown on the plot are the lines where the propeller efficiency improvement is 5% and 10%.

Jbowman90 at 14:32, 24 December 2007

2007-12-24T14:32:12Z

← Older revision		Revision as of 14:32, 24 December 2007
Line 8:		Line 8:

	It can be shown that the reduction in takeoff distance is a combination of two factors. The first is due to raw propeller efficiency improvement. More efficiency means more of the original 150HP makes it into the air as thrust. The reduction in takeoff distance due to the first factor is approximately the percent increase in propeller efficiency. The second factor also contains propeller efficiency improvement but also the effect of the additional brake power from the High Compression STC. More specifically, the second factor is the product of the ratio of propeller efficiencies and the ratio of the extra brake power (7.5 HP) to the original brake power (150 HP) of the engine.		It can be shown that the reduction in takeoff distance is a combination of two factors. The first is due to raw propeller efficiency improvement. More efficiency means more of the original 150HP makes it into the air as thrust. The reduction in takeoff distance due to the first factor is approximately the percent increase in propeller efficiency. The second factor also contains propeller efficiency improvement but also the effect of the additional brake power from the High Compression STC. More specifically, the second factor is the product of the ratio of propeller efficiencies and the ratio of the extra brake power (7.5 HP) to the original brake power (150 HP) of the engine.

			[[Image:takeoff_distance_improvement.png\|thumb\|300 px\|Takeoff Distance Reduction]]

	Although actual propeller efficiencies numbers are not available, assume an overall 10% improvement. Then the first factor gives an approximate reduction in takeoff distance of 10%, and the second factor gives a reduction in takeoff distance of about 5% ( (1 + 0.1)*7.5/150 ). The effect that the High Compression STC has on propeller efficiency is two (2) times the effect of the additional power from the High Compression STC. For a 20% improvement in efficiency, these factors are 20% and 6% respectively. So the effect that the High Compression STC has on propeller efficiency is now three (3) times the effect of the additional power from the High Compression STC! For takeoff distance, the main impact of the High Compression STC is to allow more of the original 150HP to be converted into thrust. The secondary impact is the additional 7.5 HP.		Although actual propeller efficiencies numbers are not available, assume an overall 10% improvement. Then the first factor gives an approximate reduction in takeoff distance of 10%, and the second factor gives a reduction in takeoff distance of about 5% ( (1 + 0.1)*7.5/150 ). The effect that the High Compression STC has on propeller efficiency is two (2) times the effect of the additional power from the High Compression STC. For a 20% improvement in efficiency, these factors are 20% and 6% respectively. So the effect that the High Compression STC has on propeller efficiency is now three (3) times the effect of the additional power from the High Compression STC! For takeoff distance, the main impact of the High Compression STC is to allow more of the original 150HP to be converted into thrust. The secondary impact is the additional 7.5 HP.

	The ~~following~~ figure illustrates the percent reduction in takeoff distance for any combination of propeller efficiency. Shown on the plot are the lines where the propeller efficiency improvement is 5% and 10%.		The figure on the right illustrates the percent reduction in takeoff distance for any combination of propeller efficiency. Shown on the plot are the lines where the propeller efficiency improvement is 5% and 10%.

	~~[[Image:takeoff_distance_improvement.png]]~~