Why is it that the turboprops are so slow to respond? When I push the throttles forward to take off, the turboprops take around 5 or 6 seconds to respond. I can see why jets would do that, but I've seen vids of King Air takeoff rolls and when the throttle is pushed forward the engine immediately spools up. Is there anything I can modify in the cfg files to make the turboprops a little more responsive?

Having flown a Kingair, I can tell you that it does take time to spool up and it also requires that you increase thrust very slowly and smoothly. If you have seen a video of a Kingair rapidly accelerating at the beginning of a take-off roll, it's because the pilot has held the brakes on, slowly allowed the engines to reach take-off thrust and then released the brakes. (A good way to ingest FOD so not always a good idea unless it's a high wing aircraft like the C130 or Twin Otter)Ian

Turboprops have a condition lever set capable of ground or beta range idle and flight idle. Ground idle is the slowest idle position and is used for ground operations like taxiing. Flight idle is engaged ehen taxxing into position for take-off and disengaged upon leaving the runway on landing. Flight idle is a faster idle so spool up time is shorter on increasing power especially if a go-around is executed or other quick increase is needed. It is not too fast for any air operation but if allowed to be engaged on the ground the aircraft at flight idle would have too much power for taxiing slowly at proper speeds.Jet turbines do not have condition levers for idle power since they do not have to deal with prop transmissions and inertia elements which slow spool-up as occurs in the turobo-prop arena.So, if you are having a problem with a turbo-prop power increase for flight operations be sure to insure the condition lever is in flight idle.

Thanks for all the great answers but I probably didn't make myself clear. What I meant was when I am taxiing and I reduce power to keep from going off the taxiway, the engine still lags big-time.In the video I saw:

(King Air 350 flight from Denver to Telluride, THIS VIDEO IS NOT MINE), the pilot does prop checks between around 4:00-6:00. When he reduces power back to idle from takeoff power in either throttle, the engines respond immediately. The condition levers are at "low idle", which I guess is safe to say is the same as ground idle. If in real life the props respond in around 2 seconds, FS takes 5 seconds. Is this due to the momentum of the propellor ? Or is this a delay built in to the gearbox? I can understand why props would lag spooling up for takeoff, but why would they lag if you chop the throttles?Oh, and by the way, are there any good quality King Air soundsets floating around on Avsim? Because the default sounds sound horrible. The Cessna 208 at least sounds decent.

Turboprops have a condition lever set capable of ground or beta range idle and flight idle. Ground idle is the slowest idle position and is used for ground operations like taxiing. Flight idle is engaged ehen taxxing into position for take-off and disengaged upon leaving the runway on landing. Flight idle is a faster idle so spool up time is shorter on increasing power especially if a go-around is executed or other quick increase is needed. It is not too fast for any air operation but if allowed to be engaged on the ground the aircraft at flight idle would have too much power for taxiing slowly at proper speeds.Jet turbines do not have condition levers for idle power since they do not have to deal with prop transmissions and inertia elements which slow spool-up as occurs in the turobo-prop arena.So, if you are having a problem with a turbo-prop power increase for flight operations be sure to insure the condition lever is in flight idle.

If I'm reading your post correctly, it sounds like you are using the default Kingair? If so, you want to buy the Aeroworx Kingair. It is one of the very few FS9 addons that realistically mimics real-world turboprop behavior. I haven't flown the default Kingair since FS9 first came out so can't really comment other than to say that if there is any resemblance between it and a real Kingair it's probably quite coincidental! :( Seriously though, if you really want to experience flying a medium GA twin turboprop, the Aeroworx Kingair can't be beaten IMHO. You will find it at Flight1 under FS2004 addons. The EFIS version can be a bit FPS challenging unless you have a good PC, but the analogue panel is FPS friendly, loads of fun to fly and is very close to the real thing and will require you to use proper procedures, especially for engine starting and ground power management.If you want a freeware turboprop addon that also comes very close to the real thing, download Rick Piper's HS748. Though I don't believe it is based on a true turboprop model, it has been tweaked enough that it comes very close to behaving like the real thing. Having spent many hours in the front office of 748's listening to the screech of two RR Darts, I can definitely attest to the sound file's accuracy too! (Which is why I have loss of hearing within certain frequency ranges! Unfortunately, my wife's voice is just outside the range. Just kidding!!!!!) :( Flight1's ATR also comes very close to the real thing as well. Ian

Thanks for the recommendations! I personally am a sucker for freeware, so I'll take the HS748 out for a spin. Oh, and by the way, if you want a realistic DC-3 model and sounds, go to douglasdc3.com and go to the FS2004 page. They have a DC-3 panel layout based on a modern DC-3, and they have realistic DC-3 flight dynamics and a sweet soundpack (both taken from experience with Ozark Airlines DC-3 N763A, the flight dynamics were rewritten by a real life DC-3 pilot). Both are awesome mods for the default DC-3. I highly recommend that you check it out!

If I'm reading your post correctly, it sounds like you are using the default Kingair? If so, you want to buy the Aeroworx Kingair. It is one of the very few FS9 addons that realistically mimics real-world turboprop behavior. I haven't flown the default Kingair since FS9 first came out so can't really comment other than to say that if there is any resemblance between it and a real Kingair it's probably quite coincidental! :( Seriously though, if you really want to experience flying a medium GA twin turboprop, the Aeroworx Kingair can't be beaten IMHO. You will find it at Flight1 under FS2004 addons. The EFIS version can be a bit FPS challenging unless you have a good PC, but the analogue panel is FPS friendly, loads of fun to fly and is very close to the real thing and will require you to use proper procedures, especially for engine starting and ground power management.If you want a freeware turboprop addon that also comes very close to the real thing, download Rick Piper's HS748. Though I don't believe it is based on a true turboprop model, it has been tweaked enough that it comes very close to behaving like the real thing. Having spent many hours in the front office of 748's listening to the screech of two RR Darts, I can definitely attest to the sound file's accuracy too! (Which is why I have loss of hearing within certain frequency ranges! Unfortunately, my wife's voice is just outside the range. Just kidding!!!!!) :( Flight1's ATR also comes very close to the real thing as well. Ian

Is there any freeware King Air out there with both realistic flight modeling (engine response included), and a good sound pack? Because I highly doubt that real turboprops take 10 seconds to respond once you throttle down. The weird thing is that reverse thrust kicks in pretty quickly

If I'm reading your post correctly, it sounds like you are using the default Kingair? If so, you want to buy the Aeroworx Kingair. It is one of the very few FS9 addons that realistically mimics real-world turboprop behavior. I haven't flown the default Kingair since FS9 first came out so can't really comment other than to say that if there is any resemblance between it and a real Kingair it's probably quite coincidental! :( Seriously though, if you really want to experience flying a medium GA twin turboprop, the Aeroworx Kingair can't be beaten IMHO. You will find it at Flight1 under FS2004 addons. The EFIS version can be a bit FPS challenging unless you have a good PC, but the analogue panel is FPS friendly, loads of fun to fly and is very close to the real thing and will require you to use proper procedures, especially for engine starting and ground power management.If you want a freeware turboprop addon that also comes very close to the real thing, download Rick Piper's HS748. Though I don't believe it is based on a true turboprop model, it has been tweaked enough that it comes very close to behaving like the real thing. Having spent many hours in the front office of 748's listening to the screech of two RR Darts, I can definitely attest to the sound file's accuracy too! (Which is why I have loss of hearing within certain frequency ranges! Unfortunately, my wife's voice is just outside the range. Just kidding!!!!!) :( Flight1's ATR also comes very close to the real thing as well. Ian

This happens in the Cessna 208 too. The turboprop also takes forever to respond when I throttle down too. See my post for details. Is this behavior representative of real turboprop behavior? Could this be due to the momentum of the propellor?

If I'm reading your post correctly, it sounds like you are using the default Kingair? If so, you want to buy the Aeroworx Kingair. It is one of the very few FS9 addons that realistically mimics real-world turboprop behavior. I haven't flown the default Kingair since FS9 first came out so can't really comment other than to say that if there is any resemblance between it and a real Kingair it's probably quite coincidental! :( Seriously though, if you really want to experience flying a medium GA twin turboprop, the Aeroworx Kingair can't be beaten IMHO. You will find it at Flight1 under FS2004 addons. The EFIS version can be a bit FPS challenging unless you have a good PC, but the analogue panel is FPS friendly, loads of fun to fly and is very close to the real thing and will require you to use proper procedures, especially for engine starting and ground power management.If you want a freeware turboprop addon that also comes very close to the real thing, download Rick Piper's HS748. Though I don't believe it is based on a true turboprop model, it has been tweaked enough that it comes very close to behaving like the real thing. Having spent many hours in the front office of 748's listening to the screech of two RR Darts, I can definitely attest to the sound file's accuracy too! (Which is why I have loss of hearing within certain frequency ranges! Unfortunately, my wife's voice is just outside the range. Just kidding!!!!!) :( Flight1's ATR also comes very close to the real thing as well. Ian

This happens in the Cessna 208 too. The turboprop also takes forever to respond when I throttle down too. See my post for details. Is this behavior representative of real turboprop behavior? Could this be due to the momentum of the propellor?

Well the prop for take-off and the last stages for arrival are at a higher rpm setting so the prop is spinning faster with a greater momentum. That represents also less of a load on the turbine so the turbine is spinning faster. While not completely correct think of an auto in first gear or similar crankshaft to axle ratio. In this condition the prop has an angle to take shallow cuts out of the atmosphere so the turbine speed is higher (%N1)to develop more turbine power with less of a prop load. At least I think I'm on the right track.

So the notoriously unrealistic default FDE ACTUALLY GOT IT RIGHT?

Well the prop for take-off and the last stages for arrival are at a higher rpm setting so the prop is spinning faster with a greater momentum. That represents also less of a load on the turbine so the turbine is spinning faster. While not completely correct think of an auto in first gear or similar crankshaft to axle ratio. In this condition the prop has an angle to take shallow cuts out of the atmosphere so the turbine speed is higher (%N1)to develop more turbine power with less of a prop load. At least I think I'm on the right track.

There is room for individual FDE designers to model that. I don't know about the default parameters but it can be done within the parameters available in the aircraft container SDK that may be designed in the .air and aircraft.cfg files. It seems that most of Newton's laws of inertia/momentum are followed.There are also two type of turbine to prop couplings that affect load on the turbine. One is pretty direct and the other has an additional fan coupling called a free coupling. If you look at a parked King Air and they have not tied the prop down in any decent breeze the prop will rotate with no power supplied to the engine. They have to tie it down since rotation without oil circulating through the governor and gear box can damage those prop couplings. That means the prop load as such in reverse doesn't drag down the turbine rotation in the first stage. I am under the flight path between Duluth and KMSP and I often hear turbo props slowly winding down as the aircraft slows to pattern speeds limited in this Class B airspace. What I'm not hearing is the swift change of the Doppler effect on the engine noise. So, if that's the way some turbines react in FS then the slow spool down on some models is correct. Also remember that air is still being pushed into the first fan due to the aircraft motion. It is just the lack of fuel not expanding it that reduces power. A turbine blade is just a special fan. Ever notice how long some window fan blades take to slow down in still air?Don't expect all of that in the default aircraft, though.Regarding prop to turbine couplings some ATR turbo props when parked temporarily at a gate have a prop brake on engine two I think. This allows engine two to keep running to furnish aircraft generator power without passengers entering and exiting the aircraft getting prop blast.There is an out of print book that you might be able to locate called The Turbine Pilot's Flight Manual written by airline pilot authors. It is meant for an audience of reciprocal engine pilots transitioning to turbine aircraft. I get a lot of information out of it having been a real/world private pilot of reciprocal engine aircraft migrating to FS turbine aircraft. This book also goes into the various airliner systems and even into a brief course on using weather radar.

So the notoriously unrealistic default FDE ACTUALLY GOT IT RIGHT?

Pardon the 3 dumb questions you are just about to read (I am not a mechanic), but1) Why is the PT6 (King Air, Cessna 208 engines modeled in FS) a free-coupling turbine? 2) Why is the PT6 always mounted backwards in the nacelle? Does the engine position have to do with weight or fuel efficiency? 3) In the Cessna 208, why is the left intake much larger than the right intake? Why doesn't it have a single large nose intake like other PT6-powered aircraft?

There is room for individual FDE designers to model that. I don't know about the default parameters but it can be done within the parameters available in the aircraft container SDK that may be designed in the .air and aircraft.cfg files. It seems that most of Newton's laws of inertia/momentum are followed.There are also two type of turbine to prop couplings that affect load on the turbine. One is pretty direct and the other has an additional fan coupling called a free coupling. If you look at a parked King Air and they have not tied the prop down in any decent breeze the prop will rotate with no power supplied to the engine. They have to tie it down since rotation without oil circulating through the governor and gear box can damage those prop couplings. That means the prop load as such in reverse doesn't drag down the turbine rotation in the first stage. I am under the flight path between Duluth and KMSP and I often hear turbo props slowly winding down as the aircraft slows to pattern speeds limited in this Class B airspace. What I'm not hearing is the swift change of the Doppler effect on the engine noise. So, if that's the way some turbines react in FS then the slow spool down on some models is correct. Also remember that air is still being pushed into the first fan due to the aircraft motion. It is just the lack of fuel not expanding it that reduces power. A turbine blade is just a special fan. Ever notice how long some window fan blades take to slow down in still air?Don't expect all of that in the default aircraft, though.Regarding prop to turbine couplings some ATR turbo props when parked temporarily at a gate have a prop brake on engine two I think. This allows engine two to keep running to furnish aircraft generator power without passengers entering and exiting the aircraft getting prop blast.There is an out of print book that you might be able to locate called The Turbine Pilot's Flight Manual written by airline pilot authors. It is meant for an audience of reciprocal engine pilots transitioning to turbine aircraft. I get a lot of information out of it having been a real/world private pilot of reciprocal engine aircraft migrating to FS turbine aircraft. This book also goes into the various airliner systems and even into a brief course on using weather radar.

I just gotta say that you analogy of the turbine engne is confusing the heck outta me!

There is room for individual FDE designers to model that. I don't know about the default parameters but it can be done within the parameters available in the aircraft container SDK that may be designed in the .air and aircraft.cfg files. It seems that most of Newton's laws of inertia/momentum are followed.There are also two type of turbine to prop couplings that affect load on the turbine. One is pretty direct and the other has an additional fan coupling called a free coupling. If you look at a parked King Air and they have not tied the prop down in any decent breeze the prop will rotate with no power supplied to the engine. They have to tie it down since rotation without oil circulating through the governor and gear box can damage those prop couplings. That means the prop load as such in reverse doesn't drag down the turbine rotation in the first stage. I am under the flight path between Duluth and KMSP and I often hear turbo props slowly winding down as the aircraft slows to pattern speeds limited in this Class B airspace. What I'm not hearing is the swift change of the Doppler effect on the engine noise. So, if that's the way some turbines react in FS then the slow spool down on some models is correct. Also remember that air is still being pushed into the first fan due to the aircraft motion. It is just the lack of fuel not expanding it that reduces power. A turbine blade is just a special fan. Ever notice how long some window fan blades take to slow down in still air?Don't expect all of that in the default aircraft, though.Regarding prop to turbine couplings some ATR turbo props when parked temporarily at a gate have a prop brake on engine two I think. This allows engine two to keep running to furnish aircraft generator power without passengers entering and exiting the aircraft getting prop blast.There is an out of print book that you might be able to locate called The Turbine Pilot's Flight Manual written by airline pilot authors. It is meant for an audience of reciprocal engine pilots transitioning to turbine aircraft. I get a lot of information out of it having been a real/world private pilot of reciprocal engine aircraft migrating to FS turbine aircraft. This book also goes into the various airliner systems and even into a brief course on using weather radar.

Basics and also explanation of the free-wheeling prop are included in this link:http://en.wikipedia.org/wiki/TurbopropThe window-fan high RPM analogy was in reference to the high RPM output turbine blades.Also read the section on the variable speed prop particularly to feathering but also negative pitch (reversse) for braking.Reversing of the turbine mount with the exhaust facing front is described here:http://en.wikipedia.org/wiki/Pratt_%26_Whitney_PT6A

That answers my question about the PT6 mounted backwards, but that still doesn't answer my free-wheeling prop question. I understand how a turboprop works.Does anybody have information on the Cessna 208 air intake? Take a look at this:http://upload.wikimedia.org/wikipedia/commons/f/ff/FedEx_Cessna_208B_Grand_Caravan_front.JPGNose shot of a Fedex Cessna 208. It has a clear view of the nose intake I was talking about. NOT MY PICTURE.It appears that the PT6 in the Caravan is mounted on its left side in the engine nacelle (looking from the pilot's perspective)? Is the right intake for the oil cooler? Bleed air? APU air? Anybody? Also, in aircraft such as the Fairey Gannet with two turboprops (RR Mambas in the Gannet's case) geared through a common gearbox driving contra-rotating propellors, which lever (e.g. prop, throttle, condition levers) and/or engine controls which propellor? The prop levers and throttles are side-by-side, and the actual props are front-and-back. I've seen vids of Gannet pilots shutting one engine down and feathering that prop. What factor dictates which engine controls which propellor?

Basics and also explanation of the free-wheeling prop are included in this link:http://en.wikipedia.org/wiki/TurbopropThe window-fan high RPM analogy was in reference to the high RPM output turbine blades.Also read the section on the variable speed prop particularly to feathering but also negative pitch (reversse) for braking.Reversing of the turbine mount with the exhaust facing front is described here:http://en.wikipedia....26_Whitney_PT6A