Skip to main content
Aviation

Return to Question

Became Hot Network Question
added 3 characters in body; edited title
Source Link
Amazon Dies In Darkness
Amazon Dies In Darkness
  • 3k
  • 4
  • 31
  • 48

How can I find the minimminimum and maximum airspeeds for efficiency with a specific prop/engine combination?

I'm operating a Cessna 180 with various wing and weight mods with a TCM IO550D engine and a McCauley Black Mac (D3A34C401/90DFA-2 3 blade (88 inch) seaplane prop. I operate Lean of Peak (LOP) for most ops, and accept some airspeed loss for the benefits of LOP. At some point of loss of airspeed, the resultant inefficiency of the power plant is counter to any fuel efficiency gained by LOP. I'm trying to understand where this airspeed intersects, at a given altitude. 

A second part of the question, is what factors affect efficiency loss at top power settings in both cruise and for takeoff? For example, continuous, unlimited full rated 300 Hp is only available at WOT and 2700 RPM, but it is insufferably loud at that RPM. McCauley indicates the prop's max pull is at 2600 RPM. What am I gaining or losing by taking off, or flying with 2600 RPM vs 2700 RPM? Is there a useful chart for evaluating engine/prop combinations?

How can I find the minim and maximum airspeeds for efficiency with a specific prop/engine combination?

I'm operating a Cessna 180 with various wing and weight mods with a TCM IO550D engine and a McCauley Black Mac (D3A34C401/90DFA-2 3 blade (88 inch) seaplane prop. I operate Lean of Peak (LOP) for most ops, and accept some airspeed loss for the benefits of LOP. At some point of loss of airspeed, the resultant inefficiency of the power plant is counter to any fuel efficiency gained by LOP. I'm trying to understand where this airspeed intersects, at a given altitude. A second part of the question, is what factors affect efficiency loss at top power settings in both cruise and for takeoff? For example, continuous, unlimited full rated 300 Hp is only available at WOT and 2700 RPM, but it is insufferably loud at that RPM. McCauley indicates the prop's max pull is at 2600 RPM. What am I gaining or losing by taking off, or flying with 2600 RPM vs 2700 RPM? Is there a useful chart for evaluating engine/prop combinations?

How can I find the minimum and maximum airspeeds for efficiency with a specific prop/engine combination?

I'm operating a Cessna 180 with various wing and weight mods with a TCM IO550D engine and a McCauley Black Mac (D3A34C401/90DFA-2 3 blade (88 inch) seaplane prop. I operate Lean of Peak (LOP) for most ops, and accept some airspeed loss for the benefits of LOP. At some point of loss of airspeed, the resultant inefficiency of the power plant is counter to any fuel efficiency gained by LOP. I'm trying to understand where this airspeed intersects, at a given altitude. 

A second part of the question, is what factors affect efficiency loss at top power settings in both cruise and for takeoff? For example, continuous, unlimited full rated 300 Hp is only available at WOT and 2700 RPM, but it is insufferably loud at that RPM. McCauley indicates the prop's max pull is at 2600 RPM. What am I gaining or losing by taking off, or flying with 2600 RPM vs 2700 RPM? Is there a useful chart for evaluating engine/prop combinations?

Source Link
DustyFlier
DustyFlier
  • 53
  • 4

How can I find the minim and maximum airspeeds for efficiency with a specific prop/engine combination?

I'm operating a Cessna 180 with various wing and weight mods with a TCM IO550D engine and a McCauley Black Mac (D3A34C401/90DFA-2 3 blade (88 inch) seaplane prop. I operate Lean of Peak (LOP) for most ops, and accept some airspeed loss for the benefits of LOP. At some point of loss of airspeed, the resultant inefficiency of the power plant is counter to any fuel efficiency gained by LOP. I'm trying to understand where this airspeed intersects, at a given altitude. A second part of the question, is what factors affect efficiency loss at top power settings in both cruise and for takeoff? For example, continuous, unlimited full rated 300 Hp is only available at WOT and 2700 RPM, but it is insufferably loud at that RPM. McCauley indicates the prop's max pull is at 2600 RPM. What am I gaining or losing by taking off, or flying with 2600 RPM vs 2700 RPM? Is there a useful chart for evaluating engine/prop combinations?