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Turboprop power settings


ilovenxstage

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Is it normal with a turboprop to climb almost at full throttle with the torque almost maxed out, and to cruise with the power only reduced a small amount? My HS748 seems to be like this, and I notice in other turboprops as well. The HS748 has simulated automatic prop RPM control, so all I am supposed to use is the throttles (even says NOT to move the prop RPM in the manual.) Also, the 748 is supposed to have a cruising speed of around 220kts, but I can barely reach 200 even with power maxed out. Hmmm...
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As with all turbo prop and even with the piston prop aircraft, be they default or 3rd party addons, I will normally reduce the prop RPM shortly after take off. I make sure to get the indicators down into the "safe" green zone (about 2500 RPM). I will use this setting for climb and then set it lower (about 2200 RPM) at cruise altitude.

 

About max cruise speed......are you flying into a headwind? What is your cruise altitude?

Still thinking about a new flightsim only computer!  ✈️

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Is it normal with a turboprop to climb almost at full throttle with the torque almost maxed out, and to cruise with the power only reduced a small amount? My HS748 seems to be like this, and I notice in other turboprops as well. The HS748 has simulated automatic prop RPM control, so all I am supposed to use is the throttles (even says NOT to move the prop RPM in the manual.) Also, the 748 is supposed to have a cruising speed of around 220kts, but I can barely reach 200 even with power maxed out. Hmmm...

 

The 748 and other turboprops are dissimilar. The engines on the 748 are Rolls-Royce Darts, early generation turboprops and therefore their opertion is NOT the same as the common operating practices of later turboprops, so asking for turboprop information and asking for 748 information are really different questions.

 

For the 748 you operate at maximum or rated take off power with or without water/methanol injection. For early generation tp's it's ALL about the temperatures so you may need to retard the throttle to meet temp requirements. 755 degrees is the normal cruise temperature, and you use the throttle to get that and accept whatever speed is derived, based on altitude and OAT.

This will result in 14,500 rpm (engine speed, not prop speed) for t/o, and about 12,500 rpm in cruise at Max Continuous Power. There is also a fuel trim, to further refine the power settings by modifying the fuel flow to adjust temperatures but I'd be very surprised if that is represented in this aircraft.

 

As I don't have the aircraft in question I cannot comment on how accurate the engine model is, but if it's freeware I suspect the engine model used is actually the default FSX - which half-heartedly represents a more modern PT6 power plant. If that is the case then all you can do is meet the peak and max continuous temp settings and accept everything that gives you. You have no control over RPM.

 

Really, I think you are trying too hard for accuracy with a freeware aircraft. If you want correct and proper turboprop operation you need sophisticated paid-for addons like the Majestic Dash 8, PMDG Jetstream 41 or Aerosoft Bronco.

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There is also a fuel trim, to further refine the power settings by modifying the fuel flow to adjust temperatures but I'd be very surprised if that is represented in this aircraft.

 

If you like surprises, consider downloading and installing it to check it out.

 

Really, I think you are trying too hard for accuracy with a freeware aircraft. If you want correct and proper turboprop operation you need sophisticated paid-for addons like the Majestic Dash 8, PMDG Jetstream 41 or Aerosoft Bronco.

 

On second thoughts, I suspect you consider my above suggestion too plebeian?

 

Wim

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Quote: 'suggestion too plebeian?'

 

What you can't do is fix it with your mouth. That's what. The HS748 is what it is and even if you could tweak it to fly 400 kts it ain't what is 'real' which is what OP wants (needs?).

Chuck B

Napamule

i7 2600K @ 3.4 Ghz (Turbo-Boost to 3.877 Ghz), Asus P8H67 Pro, Super Talent 8 Gb DDR3/1333 Dual Channel, XFX Radeon R7-360B 2Gb DDR5, Corsair 650 W PSU, Dell 23 in (2048x1152), Windows7 Pro 64 bit, MS Sidewinder Precision 2 Joy, Logitech K-360 wireless KB & Mouse, Targus PAUK10U USB Keypad for Throttle (F1 to F4)/Spoiler/Tailhook/Wing Fold/Pitch Trim/Parking Brake/Snap to 2D Panel/View Change. Installed on 250 Gb (D:). FS9 and FSX Acceleration (locked at 30 FPS).
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What you can't do is fix it with your mouth. That's what. The HS748 is what it is and even if you could tweak it to fly 400 kts it ain't what is 'real' which is what OP wants (needs?).

Says the man who put a Kingair panel in the HS748 to get it working.

Enough said. Stick with the racing cars, Chuck.

 

Wim

b727fcaptain.jpgx701captain5.jpg
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Ha Ha! Good one. Ok. Will stick with my vehicles as suggested. No problem.

Chuck B

Napamule

i7 2600K @ 3.4 Ghz (Turbo-Boost to 3.877 Ghz), Asus P8H67 Pro, Super Talent 8 Gb DDR3/1333 Dual Channel, XFX Radeon R7-360B 2Gb DDR5, Corsair 650 W PSU, Dell 23 in (2048x1152), Windows7 Pro 64 bit, MS Sidewinder Precision 2 Joy, Logitech K-360 wireless KB & Mouse, Targus PAUK10U USB Keypad for Throttle (F1 to F4)/Spoiler/Tailhook/Wing Fold/Pitch Trim/Parking Brake/Snap to 2D Panel/View Change. Installed on 250 Gb (D:). FS9 and FSX Acceleration (locked at 30 FPS).
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The 748 and other turboprops are dissimilar. The engines on the 748 are Rolls-Royce Darts, early generation turboprops and therefore their opertion is NOT the same as the common operating practices of later turboprops, so asking for turboprop information and asking for 748 information are really different questions.

 

For the 748 you operate at maximum or rated take off power with or without water/methanol injection. For early generation tp's it's ALL about the temperatures so you may need to retard the throttle to meet temp requirements. 755 degrees is the normal cruise temperature, and you use the throttle to get that and accept whatever speed is derived, based on altitude and OAT.

This will result in 14,500 rpm (engine speed, not prop speed) for t/o, and about 12,500 rpm in cruise at Max Continuous Power. There is also a fuel trim, to further refine the power settings by modifying the fuel flow to adjust temperatures but I'd be very surprised if that is represented in this aircraft.

 

As I don't have the aircraft in question I cannot comment on how accurate the engine model is, but if it's freeware I suspect the engine model used is actually the default FSX - which half-heartedly represents a more modern PT6 power plant. If that is the case then all you can do is meet the peak and max continuous temp settings and accept everything that gives you. You have no control over RPM.

 

Really, I think you are trying too hard for accuracy with a freeware aircraft. If you want correct and proper turboprop operation you need sophisticated paid-for addons like the Majestic Dash 8, PMDG Jetstream 41 or Aerosoft Bronco.

 

Thank you for that information. The fuel trimming is represented on HS748, but do not know how accurate it is. I am accustomed to modern turboprop with control of both throttle and prop rpm. The Dart engines are deffinately different like you say, but also may be in accurate.

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