Climb - Revision history

Garygbond: /* Climb Gradients */

2021-04-29T13:29:45Z

Climb Gradients

← Older revision		Revision as of 13:29, 29 April 2021
Line 14:		Line 14:

	== Climb Gradients ==		== Climb Gradients ==
	Climb performance can also be thought of in terms of altitude gained per distance traveled. The formula to derive climb gradient is (vertical speed x 60) / groundspeed and the units are typically feet per nautical mile. Note that standard IFR departure gradients require minimum 200 ft/nm. This table [https://bondline.org/wiki/File:Tiger_climb_gradient_table.pdf#Tiger Climb Gradient Table] and graphs show climb gradients for the AA-5B Tiger for zero wind and 10-knot headwind conditions with gradients below 200 ft/nm highlighted in red and gradients between 200 and 300 ft/nm highlighted in yellow. These are based on POH values with estimated TAS calculations; they require maximum available power (leaned as necessary), no flaps. Your specific numbers will vary.		Climb performance can also be thought of in terms of altitude gained per distance traveled. The formula to derive climb gradient is (vertical speed x 60) / groundspeed and the units are typically feet per nautical mile. Note that standard IFR departure gradients require minimum 200 ft/nm. This table [https://bondline.org/wiki/File:Tiger_climb_gradient_table.pdf#Tiger Climb Gradient Table] and graphs [https://bondline.org/wiki/File:Tiger_climb_gradient_graphs.pdf#Tiger Climb Gradient Graphs] show climb gradients for the AA-5B Tiger for zero wind and 10-knot headwind conditions with gradients below 200 ft/nm highlighted in red and gradients between 200 and 300 ft/nm highlighted in yellow. These are based on POH values with estimated TAS calculations; they require maximum available power (leaned as necessary), no flaps. Your specific numbers will vary.

Garygbond: /* Climb Gradients */

2021-04-29T13:25:33Z

Climb Gradients

← Older revision		Revision as of 13:25, 29 April 2021
Line 14:		Line 14:

	== Climb Gradients ==		== Climb Gradients ==
	Climb performance can also be thought of in terms of altitude gained per distance traveled. The formula to derive climb gradient is (vertical speed x 60) / groundspeed and the units are typically feet per nautical mile. Note that standard IFR departure gradients require minimum 200 ft/nm. This table [https://bondline.org/wiki/File:~~Tiger_gradient~~.~~png~~#Tiger Climb Gradient Table] and graphs show climb gradients for the AA-5B Tiger for zero wind and 10-knot headwind conditions with gradients below 200 ft/nm highlighted in red and gradients between 200 and 300 ft/nm highlighted in yellow. These are based on POH values with estimated TAS calculations; they require maximum available power (leaned as necessary), no flaps. Your specific numbers will vary.		Climb performance can also be thought of in terms of altitude gained per distance traveled. The formula to derive climb gradient is (vertical speed x 60) / groundspeed and the units are typically feet per nautical mile. Note that standard IFR departure gradients require minimum 200 ft/nm. This table [https://bondline.org/wiki/File:Tiger_climb_gradient_table.pdf#Tiger Climb Gradient Table] and graphs show climb gradients for the AA-5B Tiger for zero wind and 10-knot headwind conditions with gradients below 200 ft/nm highlighted in red and gradients between 200 and 300 ft/nm highlighted in yellow. These are based on POH values with estimated TAS calculations; they require maximum available power (leaned as necessary), no flaps. Your specific numbers will vary.

Garygbond: /* Climb Gradients */

2021-04-29T13:19:00Z

Climb Gradients

← Older revision		Revision as of 13:19, 29 April 2021
Line 14:		Line 14:

	== Climb Gradients ==		== Climb Gradients ==
	Climb performance can also be thought of in terms of altitude gained per distance traveled. The formula to derive climb gradient is (vertical speed x 60) / groundspeed and the units are typically feet per nautical mile. Note that standard IFR departure gradients require minimum 200 ft/nm. This table and graphs show climb gradients for the AA-5B Tiger for zero wind and 10-knot headwind conditions with gradients below 200 ft/nm highlighted in red and gradients between 200 and 300 ft/nm highlighted in yellow. These are based on POH values with estimated TAS calculations; they require maximum available power (leaned as necessary), no flaps. Your specific numbers will vary.		Climb performance can also be thought of in terms of altitude gained per distance traveled. The formula to derive climb gradient is (vertical speed x 60) / groundspeed and the units are typically feet per nautical mile. Note that standard IFR departure gradients require minimum 200 ft/nm. This table [https://bondline.org/wiki/File:Tiger_gradient.png#Tiger Climb Gradient Table] and graphs show climb gradients for the AA-5B Tiger for zero wind and 10-knot headwind conditions with gradients below 200 ft/nm highlighted in red and gradients between 200 and 300 ft/nm highlighted in yellow. These are based on POH values with estimated TAS calculations; they require maximum available power (leaned as necessary), no flaps. Your specific numbers will vary.

Garygbond at 11:28, 29 April 2021

2021-04-29T11:28:14Z

← Older revision		Revision as of 11:28, 29 April 2021
Line 14:		Line 14:

	== Climb Gradients ==		== Climb Gradients ==
	Climb performance can also be thought of in terms of altitude gained per distance traveled. The formula to derive climb gradient is (vertical speed x 60) / groundspeed and the units are typically feet per nautical mile. Note that standard IFR departure gradients require minimum 200 ft/nm. This table ~~[https://bondline.org/wiki/File:Tiger_climb_gradient.jpg#Tiger Climb Gradients]~~ and graphs ~~[https://bondline.org/wiki/File:Tiger_climb_gradients_graphs.jpg#Graphs Climb Gradient Graphs] shows~~ climb gradients for the AA-5B Tiger for zero wind and 10-knot headwind conditions with gradients below 200 ft/nm highlighted in red and gradients between 200 and 300 ft/nm highlighted in yellow. These are based on POH values, require maximum available power (leaned as necessary), no flaps~~, and your~~ specific numbers will vary.		Climb performance can also be thought of in terms of altitude gained per distance traveled. The formula to derive climb gradient is (vertical speed x 60) / groundspeed and the units are typically feet per nautical mile. Note that standard IFR departure gradients require minimum 200 ft/nm. This table and graphs show climb gradients for the AA-5B Tiger for zero wind and 10-knot headwind conditions with gradients below 200 ft/nm highlighted in red and gradients between 200 and 300 ft/nm highlighted in yellow. These are based on POH values with estimated TAS calculations; they require maximum available power (leaned as necessary), no flaps. Your specific numbers will vary.

Garygbond: /* Climb Gradients */

2021-04-28T21:51:05Z

Climb Gradients

← Older revision		Revision as of 21:51, 28 April 2021
Line 14:		Line 14:

	== Climb Gradients ==		== Climb Gradients ==
	Climb performance can also be thought of in terms of altitude gained per distance traveled. The formula to derive climb gradient is (vertical speed x 60) / groundspeed and the units are typically feet per nautical mile. Note that standard IFR departure gradients require minimum 200 ft/nm. This table [https://bondline.org/wiki/File:Tiger_climb_gradient.jpg#Tiger Climb Gradients] shows climb gradients for the AA-5B Tiger for zero wind and 10-knot headwind conditions with gradients below 200 ft/nm highlighted in red and gradients between 200 and 300 ft/nm highlighted in yellow. These are based on POH values, require maximum available power (leaned as necessary), no flaps, and your specific numbers will vary.		Climb performance can also be thought of in terms of altitude gained per distance traveled. The formula to derive climb gradient is (vertical speed x 60) / groundspeed and the units are typically feet per nautical mile. Note that standard IFR departure gradients require minimum 200 ft/nm. This table [https://bondline.org/wiki/File:Tiger_climb_gradient.jpg#Tiger Climb Gradients] and graphs [https://bondline.org/wiki/File:Tiger_climb_gradients_graphs.jpg#Graphs Climb Gradient Graphs] shows climb gradients for the AA-5B Tiger for zero wind and 10-knot headwind conditions with gradients below 200 ft/nm highlighted in red and gradients between 200 and 300 ft/nm highlighted in yellow. These are based on POH values, require maximum available power (leaned as necessary), no flaps, and your specific numbers will vary.

Garygbond: /* Climb Gradients */

2021-04-28T20:32:59Z

Climb Gradients

← Older revision		Revision as of 20:32, 28 April 2021
Line 14:		Line 14:

	== Climb Gradients ==		== Climb Gradients ==
	Climb performance can also be thought of in terms of altitude gained per distance traveled. The formula to derive climb gradient is (vertical speed x 60) / groundspeed and the units are typically feet per nautical mile. Note that standard IFR departure gradients require minimum 200 ft/nm. This table [https://bondline.org/wiki/File:Tiger_climb_gradient.jpg#Tiger Climb Gradients] shows climb gradients for the AA-5B Tiger for zero wind and 10-knot headwind conditions with gradients below 200 ft/nm highlighted in red and gradients between 200 and 300 ft/nm highlighted in yellow.		Climb performance can also be thought of in terms of altitude gained per distance traveled. The formula to derive climb gradient is (vertical speed x 60) / groundspeed and the units are typically feet per nautical mile. Note that standard IFR departure gradients require minimum 200 ft/nm. This table [https://bondline.org/wiki/File:Tiger_climb_gradient.jpg#Tiger Climb Gradients] shows climb gradients for the AA-5B Tiger for zero wind and 10-knot headwind conditions with gradients below 200 ft/nm highlighted in red and gradients between 200 and 300 ft/nm highlighted in yellow. These are based on POH values, require maximum available power (leaned as necessary), no flaps, and your specific numbers will vary.

Garygbond: Added information and link to table for climb gradient for AA-5B Tiger.

2021-04-28T20:29:52Z

Added information and link to table for climb gradient for AA-5B Tiger.

← Older revision		Revision as of 20:29, 28 April 2021
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	The story does not really end there. Considering the higher power output of the engine-propeller combination and the relative location of the minimum of the drag power curve (the difference of these curves is the excess power), the maximum rate-of-climb will usually occur at a slightly higher speed than with the old engine. Because most 4-seat Grumman pilots climb the old engine at speeds higher than best rate-of-climb, flying the new engine at the same speed will result in more than the 22% increase calculated here. This is because the original excess power will be lower than 44HP and the thrust power increase from flying at the higher speed will be greater. However, no attempt is made to estimate these effects.		The story does not really end there. Considering the higher power output of the engine-propeller combination and the relative location of the minimum of the drag power curve (the difference of these curves is the excess power), the maximum rate-of-climb will usually occur at a slightly higher speed than with the old engine. Because most 4-seat Grumman pilots climb the old engine at speeds higher than best rate-of-climb, flying the new engine at the same speed will result in more than the 22% increase calculated here. This is because the original excess power will be lower than 44HP and the thrust power increase from flying at the higher speed will be greater. However, no attempt is made to estimate these effects.

			== Climb Gradients ==
			Climb performance can also be thought of in terms of altitude gained per distance traveled. The formula to derive climb gradient is (vertical speed x 60) / groundspeed and the units are typically feet per nautical mile. Note that standard IFR departure gradients require minimum 200 ft/nm. This table [https://bondline.org/wiki/File:Tiger_climb_gradient.jpg#Tiger Climb Gradients] shows climb gradients for the AA-5B Tiger for zero wind and 10-knot headwind conditions with gradients below 200 ft/nm highlighted in red and gradients between 200 and 300 ft/nm highlighted in yellow.

Jbowman90: fixed equation

2008-01-21T21:47:28Z

fixed equation

← Older revision		Revision as of 21:47, 21 January 2008
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	The effect of these performance enhancers is a common topic on the [http://grumman.net Grumman Gang]. Until estimated performance data is available for the PowerFlow exhaust and Sensenich propeller, only the improvement due to the High Compression STC is discussed. Data approximating the performance impact due to the High Compression STC is discussed in [[Basic Engine and Propeller Performance]] and will be used here.		The effect of these performance enhancers is a common topic on the [http://grumman.net Grumman Gang]. Until estimated performance data is available for the PowerFlow exhaust and Sensenich propeller, only the improvement due to the High Compression STC is discussed. Data approximating the performance impact due to the High Compression STC is discussed in [[Basic Engine and Propeller Performance]] and will be used here.

	The improved rate-of-climb can be computed from the original rate-of-climb as follows: new rate-of-climb = old rate-of-climb + (new - old thrust power / aircraft weight). Recognizing the data in [[Basic Engine and Propeller Performance]] is somewhat off due to the generic propeller curves and handpicking points off of those curves, at 80 KIAS the old and new thrust is 458 lbs and 498 lbs (an increase of 8%), respectively. When converted to thrust power at 80 KIAS, this results in a net excess horsepower increase of 9.7 HP, which translates into a net increase in rate-of-climb of approximately 22%, from 660 ft/min to 805 ft/min at Cheetah gross weight. Note that this is from the High Compression STC alone without any propeller or exhaust improvements. But the shocker to most is that a 22% increase in rate-of-climb can be obtained from a 6.7% increase in maximum rate engine power.		The improved rate-of-climb can be computed from the original rate-of-climb as follows: new rate-of-climb = old rate-of-climb + (new - old thrust power) / aircraft weight. Recognizing the data in [[Basic Engine and Propeller Performance]] is somewhat off due to the generic propeller curves and handpicking points off of those curves, at 80 KIAS the old and new thrust is 458 lbs and 498 lbs (an increase of 8%), respectively. When converted to thrust power at 80 KIAS, this results in a net excess horsepower increase of 9.7 HP, which translates into a net increase in rate-of-climb of approximately 22%, from 660 ft/min to 805 ft/min at Cheetah gross weight. Note that this is from the High Compression STC alone without any propeller or exhaust improvements. But the shocker to most is that a 22% increase in rate-of-climb can be obtained from a 6.7% increase in maximum rate engine power.

	The story does not really end there. Considering the higher power output of the engine-propeller combination and the relative location of the minimum of the drag power curve (the difference of these curves is the excess power), the maximum rate-of-climb will usually occur at a slightly higher speed than with the old engine. Because most 4-seat Grumman pilots climb the old engine at speeds higher than best rate-of-climb, flying the new engine at the same speed will result in more than the 22% increase calculated here. This is because the original excess power will be lower than 44HP and the thrust power increase from flying at the higher speed will be greater. However, no attempt is made to estimate these effects.		The story does not really end there. Considering the higher power output of the engine-propeller combination and the relative location of the minimum of the drag power curve (the difference of these curves is the excess power), the maximum rate-of-climb will usually occur at a slightly higher speed than with the old engine. Because most 4-seat Grumman pilots climb the old engine at speeds higher than best rate-of-climb, flying the new engine at the same speed will result in more than the 22% increase calculated here. This is because the original excess power will be lower than 44HP and the thrust power increase from flying at the higher speed will be greater. However, no attempt is made to estimate these effects.

Jbowman90: Add commentary about how the best rate-of-climb speed will change with the high compression STC

2008-01-21T17:15:24Z

Add commentary about how the best rate-of-climb speed will change with the high compression STC

← Older revision		Revision as of 17:15, 21 January 2008
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	The improved rate-of-climb can be computed from the original rate-of-climb as follows: new rate-of-climb = old rate-of-climb + (new - old thrust power / aircraft weight). Recognizing the data in [[Basic Engine and Propeller Performance]] is somewhat off due to the generic propeller curves and handpicking points off of those curves, at 80 KIAS the old and new thrust is 458 lbs and 498 lbs (an increase of 8%), respectively. When converted to thrust power at 80 KIAS, this results in a net excess horsepower increase of 9.7 HP, which translates into a net increase in rate-of-climb of approximately 22%, from 660 ft/min to 805 ft/min at Cheetah gross weight. Note that this is from the High Compression STC alone without any propeller or exhaust improvements. But the shocker to most is that a 22% increase in rate-of-climb can be obtained from a 6.7% increase in maximum rate engine power.		The improved rate-of-climb can be computed from the original rate-of-climb as follows: new rate-of-climb = old rate-of-climb + (new - old thrust power / aircraft weight). Recognizing the data in [[Basic Engine and Propeller Performance]] is somewhat off due to the generic propeller curves and handpicking points off of those curves, at 80 KIAS the old and new thrust is 458 lbs and 498 lbs (an increase of 8%), respectively. When converted to thrust power at 80 KIAS, this results in a net excess horsepower increase of 9.7 HP, which translates into a net increase in rate-of-climb of approximately 22%, from 660 ft/min to 805 ft/min at Cheetah gross weight. Note that this is from the High Compression STC alone without any propeller or exhaust improvements. But the shocker to most is that a 22% increase in rate-of-climb can be obtained from a 6.7% increase in maximum rate engine power.

			The story does not really end there. Considering the higher power output of the engine-propeller combination and the relative location of the minimum of the drag power curve (the difference of these curves is the excess power), the maximum rate-of-climb will usually occur at a slightly higher speed than with the old engine. Because most 4-seat Grumman pilots climb the old engine at speeds higher than best rate-of-climb, flying the new engine at the same speed will result in more than the 22% increase calculated here. This is because the original excess power will be lower than 44HP and the thrust power increase from flying at the higher speed will be greater. However, no attempt is made to estimate these effects.

Jbowman90 at 17:06, 21 January 2008

2008-01-21T17:06:05Z

← Older revision		Revision as of 17:06, 21 January 2008
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	Rate-of-climb (ROC) is identically the specific excess power. Excess power is the difference between how much thrust power the propeller is putting into the air and how much power it takes to overcome drag. Specific excess power is the excess power divided by the aircraft's weight. Because ROC is related to ''excess'' power, doubling or halving the thrust power does not mean the rate-of-climb or descent is doubled or halved. A good example is a light twin such as an [http://en.wikipedia.org/wiki/Piper_Aztec Apache]. If an Apache loses an engine (thrust power reduced by half), the remaining engine usually does not have enough power to even sustain level flight.		Rate-of-climb (ROC) is identically the specific excess power. Excess power is the difference between how much thrust power the propeller is putting into the air and how much power it takes to overcome drag. Specific excess power is the excess power divided by the aircraft's weight. Because ROC is related to ''excess'' power, doubling or halving the thrust power does not mean the rate-of-climb or descent is doubled or halved. A good example is a light twin such as an [http://en.wikipedia.org/wiki/Piper_Aztec Apache]. If an Apache loses an engine (thrust power reduced by half), the remaining engine usually does not have enough power to even sustain level flight.

	Using the numbers quoted in the Pilot's Operating Handbook, the rate-of-climb at a gross weight of 2200 lbs is ~~600~~ ft/min. By definition, the excess power of a [http://en.wikipedia.org/wiki/Grumman_American_AA-5#AA-5A_Cheetah Cheetah] in the original factory configuration is 40 HP. Therefore, even small amount of additional brake power or improvements in propeller efficiency will have a large impact on excess power and, therefore, rate-of-climb.		Using the numbers quoted in the Pilot's Operating Handbook for a Cheetah, the rate-of-climb at a gross weight of 2200 lbs is 660 ft/min. By definition, the excess power of a [http://en.wikipedia.org/wiki/Grumman_American_AA-5#AA-5A_Cheetah Cheetah] in the original factory configuration is 44 HP. Therefore, even small amount of additional brake power or improvements in propeller efficiency will have a large impact on excess power and, therefore, rate-of-climb.

	== 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 effect of these performance enhancers is a common topic on the [http://grumman.net Grumman Gang]. Until estimated performance data is available for the PowerFlow exhaust and Sensenich propeller, only the improvement due to the High Compression STC is discussed. Data approximating the performance impact due to the High Compression STC is discussed in [[Basic Engine and Propeller Performance]] and will be used here.

	~~This is a common topic on~~ the ~~Grumman Gang. Because each aircraft is a little different in weight, drag, engine, and prop, it is difficult to give a single estimate for the improvement in~~ rate-of-climb. However, like the [[Takeoff\|takeoff analysis]], the [[High Compression STC]] not only adds additional brake power but also turns the [http://en.wikipedia.org/wiki/Propeller propeller] at a higher rotational speed thereby improving the [http:~~//en.wikipedia.org/wiki/Propeller#Aviation efficiency].~~		The improved rate-of-climb can be computed from the original rate-of-climb as follows: new rate-of-climb = old rate-of-climb + (new - old thrust power / aircraft weight). Recognizing the data in [[Basic Engine and Propeller Performance]] is somewhat off due to the generic propeller curves and handpicking points off of those curves, at 80 KIAS the old and new thrust is 458 lbs and 498 lbs (an increase of 8%), respectively. When converted to thrust power at 80 KIAS, this results in a net excess horsepower increase of 9.7 HP, which translates into a net increase in rate-of-climb of approximately 22%, from 660 ft/min to 805 ft/min at Cheetah gross weight. Note that this is from the High Compression STC alone without any propeller or exhaust improvements. But the shocker to most is that a 22% increase in rate-of-climb can be obtained from a 6.7% increase in maximum rate engine power.

	~~[[Image:rate_of_climb_improvement.png\|thumb\|300 px\|Rate~~-of-~~Climb Improvement]]~~

	~~The~~ rate-of-climb ~~improvement therefore has two factors. First is the additional 7.5 brake horsepower at the higher propeller efficiency. Second is the additional~~ thrust power ~~from the original 150 HP operating at the higher efficiency~~. ~~This second term~~ is ~~just~~ the ~~product~~ of the ~~original 150HP~~ and ~~the difference between the original~~ and ~~new propeller efficiencies~~. ~~Dividing by weight and the original rate-of-climb yields the improvement~~ in ~~rate-~~of~~-climb for both factors. Assuming the original propeller efficiency is about 0~~.7, ~~the improved efficiency is 0.75, weight is 2200 lbs, and the original~~ rate-of-climb ~~is 600~~ ft/min~~, the effect of the improved propeller efficiency~~ is ~~approximately 18% and the effect of the additional 7.5 brake horsepower~~ from the High Compression STC is ~~approximately 15~~%. ~~Unlike the [[Takeoff\|takeoff analysis]] where the improved propeller efficiency was the main effect, both improved propeller efficiency and the additional brake~~ power ~~are roughly equal effects~~.