Aces High Bulletin Board
General Forums => Wishlist => Topic started by: Brownien on February 08, 2012, 12:33:53 AM
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engine damage! ya get hit and it dies. what do you do? glide as far as you can and crash land. but what if you could attempt to restart the engine? through a series of engine control manipulations to say find a 'sweet spot' where it will restart and run at say half power? or at a lower power based on the amount of damage? would be neat to be able to at least try to limp home. possibly also have the option to feather the prop if need be? could be exciting! :joystick:
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No amount of engine controls will put the oil back in or reconnect piston rods or such that have been blown apart.
I know that the multi-engined aircraft in AH already feather their props on engines that have been shut off. Single engined aircraft did not have the ability to feather their props.
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That depends on what's damaged. I like this idea but it will be too hard to implement and wont make a significant difference in the end.
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Single engined aircraft did not have the ability to feather their props.
Sure they do. As long as the aircraft has a constant speed prop it can be feathered, makes no difference on the number of engines the aircraft has.
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brownien as much as I love your idea and lots of other guys do as we have all lost engines on the way home or so close to the pavement that it's frustrating sometimes. well the idea of playing this game is for things to work like they did in ww2. and engines in ww2 that got hit lost chunks out of them or oil or whatever and no amount of pulling or yanking would fix that. so basically as much as I would love to have the ability to do it, I love the fact that we pretend to fly just like real airplanes do.
for lots me and lots of guys it's not the getting back home that is important, it's the actual flying against other airplanes that is the main thing :salute.
semp
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brownien as much as I love your idea and lots of other guys do as we have all lost engines on the way home or so close to the pavement that it's frustrating sometimes. well the idea of playing this game is for things to work like they did in ww2. and engines in ww2 that got hit lost chunks out of them or oil or whatever and no amount of pulling or yanking would fix that. so basically as much as I would love to have the ability to do it, I love the fact that we pretend to fly just like real airplanes do.
for lots me and lots of guys it's not the getting back home that is important, it's the actual flying against other airplanes that is the main thing :salute.
semp
The engine does not need all it's cylinders working to provide power. As long as the damaged part of the engine will not block the rest of the engine from moving the engine will still work.
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Sure they do. As long as the aircraft has a constant speed prop it can be feathered, makes no difference on the number of engines the aircraft has.
My understanding is that they did not have that ability during WWII. The designers did not see any reason to build the capability to turn the blade edge straight into the wind.
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That depends on what's damaged. I like this idea but it will be too hard to implement and wont make a significant difference in the end.
Agree, trying to make the damage "complex" would be a serious change in the game and not likely an easy one.
I'd rather have new toys added to the game, He-111 and D.520 before we get some complex damage system.
The game has to have a balance of Arcade and simulation to please the crowd as a whole. Its already complex in a way, being if your fuel tank gets hit by a .303 it leaks slowly - rather then a hit from a 20mm in which it will drain out almost instantly.
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The engine does not need all it's cylinders working to provide power. As long as the damaged part of the engine will not block the rest of the engine from moving the engine will still work.
but that's not what he's talking about. he's talking about restarting an engine that had died due to damage.
semp
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My understanding is that they did not have that ability during WWII. The designers did not see any reason to build the capability to turn the blade edge straight into the wind.
Your partially correct, actually my response above was also a bit inaccurate.
All constant speed propellers can feather, however not all can feather completely. When your engine stops you typically want to do two thing to decrease your drag, feather the prop (so it would have minimal wind resistance) and stop the blades as it takes energy to rotate them (and your engine and they are connected to it), that energy is translated into drag.
On a multi-engine aircraft you normally have full-feathering props. When you loose one engine you lost 50% of your power and you're drag also significantly increases. Quite often that 2nd engine has enough power to keep you in the air, but because of the extra drag created by the failed engine your remaining engine can not keep you airborne. So what you do is reduce the drag by as much as possible by feather the prop and stopping the blades.
Now on a single engine aircraft when you loose your engine your screwed, at that point all you care about is increasing your glide distance. All the extra metal that would fully feather your prop is heavy and when gliding you want to reduce the weight by as much as possible so single engine aircraft typically don't have fully-feathering props. Now technically you would still want to feather your prop as much as possible but because in that position it will be windmilling it would still be creating a lot of drag. Letting your prop windmill is one of the worst thing you can do (as I explained above) therefor most aircraft manufacturers design their governors to move the prop to the opposite of feathering position. This will significantly help you stop the prop. When you don't have the option to fully feather the prop keeping the blades in an unfeathered position and stationary is much better than keeping them in an almost feathered positioned and windmilling.
Some aircraft manufacturers still give the single engine aircraft the ability to fully feather the prop, I believe Beechcraft did that on the T-6. So it's debatable on what is better, but most single engine aircraft can not fully-feather their prop.
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but that's not what he's talking about. he's talking about restarting an engine that had died due to damage.
semp
Ah, right.
I'm not a mechanic but as far as I understand if the engine already stops due to mechanical damage it would be next to impossible to re-start it without fixing the damage. So yes you can try re-starting it, but chances are it's not going to help.
Technically you can already try re-starting it by pressing the "e" key. ;)
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Your partially correct, actually my response above was also a bit inaccurate.
All constant speed propellers can feather, however not all can feather completely. When your engine stops you typically want to do two thing to decrease your drag, feather the prop (so it would have minimal wind resistance) and stop the blades as it takes energy to rotate them (and your engine and they are connected to it), that energy is translated into drag.
On a multi-engine aircraft you normally have full-feathering props. When you loose one engine you lost 50% of your power and you're drag also significantly increases. Quite often that 2nd engine has enough power to keep you in the air, but because of the extra drag created by the failed engine your remaining engine can not keep you airborne. So what you do is reduce the drag by as much as possible by feather the prop and stopping the blades.
Now on a single engine aircraft when you loose your engine your screwed, at that point all you care about is increasing your glide distance. All the extra metal that would fully feather your prop is heavy and when gliding you want to reduce the weight by as much as possible so single engine aircraft typically don't have fully-feathering props. Now technically you would still want to feather your prop as much as possible but because in that position it will be windmilling it would still be creating a lot of drag. Letting your prop windmill is one of the worst thing you can do (as I explained above) therefor most aircraft manufacturers design their governors to move the prop to the opposite of feathering position. This will significantly help you stop the prop. When you don't have the option to fully feather the prop keeping the blades in an unfeathered position and stationary is much better than keeping them in an almost feathered positioned and windmilling.
Some aircraft manufacturers still give the single engine aircraft the ability to fully feather the prop, I believe Beechcraft did that on the T-6. So it's debatable on what is better, but most single engine aircraft can not fully-feather their prop.
That matches my understanding of WWII single and multi-engined fighter props in regards to feathering.
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Fly one with 2 engines......problem solved :D
(http://i888.photobucket.com/albums/ac82/mbailey166066/2011%20airshow/IMG_4356.jpg)
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I glide multiple sectors often and I find it strange that some planes will still windmill at 13mph in a vertical stall.
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my point is that currently the game model is either an oil hit, radiator hit, or a catastrophic engine failure that leaves you with no power. durring the war there were many cases of engine damage to cylinders (particularly radial engines) that would either stall the engine and would need to be restarted, or would allow it to run at a decreased capacity. many a good pilot could restart an engine with some fiddling and get it to run with even chunks missing form the block. i partially dislike all the autimation in the game and would like to see more control over aircraft systems. may be a bit larger learning curve but once you get a hang on it, there would be a lot more to squeeze out of the airframe.
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Are you ready to juggle prop speed, ignition timing, mixture, supercharger speed, and applying different stages of anti-detonation?
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All the extra metal that would fully feather your prop is heavy and when gliding you want to reduce the weight by as much as possible so single engine aircraft typically don't have fully-feathering props. Now technically you would still want to feather your prop as much as possible but because in that position it will be windmilling it would still be creating a lot of drag. Letting your prop windmill is one of the worst thing you can do (as I explained above) therefor most aircraft manufacturers design their governors to move the prop to the opposite of feathering position. This will significantly help you stop the prop. When you don't have the option to fully feather the prop keeping the blades in an unfeathered position and stationary is much better than keeping them in an almost feathered positioned and windmilling.
Some aircraft manufacturers still give the single engine aircraft the ability to fully feather the prop, I believe Beechcraft did that on the T-6. So it's debatable on what is better, but most single engine aircraft can not fully-feather their prop.
You've never lost an engine have you. :D
While stopping the prop would be nice it really isn't practical and greatly increases the risk of a stall/spin. The prop won't stop until you are below flying speed on many aircraft (depends on the engine/prop weight/etc). On the 182 and 206 the prop would stop after touchdown and slowing -- I know this from actually making deadstick landings in both aircraft types. Anyone telling you to stop the prop has most likely never actually lost an engine and experienced how the engine/prop/aircraft perform. While your putzing about trying to get the prop stopped you're wasting time and altitude you should be using to find a place to safely put the airplane on the ground while trying to restart the engine (if appropriate).
As you said most props will fail to the low pitch/high RPM positiion -- but they will not go beyond the low pitch stop. The low pitch INCREASES prop RPM so to reduce drag you need to reduce prop RPM which you can do if you still have enough oil/oil pressue to operate the prop.
The T6 Texan II is a turbine which is a completely different animal and not applicable to this conversation.
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my point is that currently the game model is either an oil hit, radiator hit, or a catastrophic engine failure that leaves you with no power. durring the war there were many cases of engine damage to cylinders (particularly radial engines) that would either stall the engine and would need to be restarted, or would allow it to run at a decreased capacity. many a good pilot could restart an engine with some fiddling and get it to run with even chunks missing form the block. i partially dislike all the autimation in the game and would like to see more control over aircraft systems. may be a bit larger learning curve but once you get a hang on it, there would be a lot more to squeeze out of the airframe.
The kind of damage that will kill your engine is also going to make the possibility of fire very likely. Anytime to take parts off an engine you are probably going to lose oil and/or fuel which creates an extreme fire hazard. Restarting the engine just might start you on fire --- not a good thing. Unless it's quit because you're run it out of gas or turned the mags off you will most likely leave it off.
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i was thinking more of throttle, rpm, prop pitch, and mixture. as for ignition timing, that was controlled mechanically, superchargers are mechanically driven by the engine although it can be to different stages and turbos being controlled by exaust flow. and as for detonation, this can be prevented from the use of mixture management and water injection.
im sure there would be some way to have an optional assist on systems management that could be turned off for those that want the full experience and realism.
-any damage to the engine that resulted in loss of fuel would most likely be directly from the manifold or a damaged cylinder, both would only result in possible poofs of flame but not a sustained fire. thats what im talking about when trying to restart, not if a carb is hit or a fuel line or supercharger, which could result in a sustained fire. but i mean when i try to restart not even the starter motor will turn it over.
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You've never lost an engine have you. :D
While stopping the prop would be nice it really isn't practical and greatly increases the risk of a stall/spin. The prop won't stop until you are below flying speed on many aircraft (depends on the engine/prop weight/etc). On the 182 and 206 the prop would stop after touchdown and slowing -- I know this from actually making deadstick landings in both aircraft types. Anyone telling you to stop the prop has most likely never actually lost an engine and experienced how the engine/prop/aircraft perform. While your putzing about trying to get the prop stopped you're wasting time and altitude you should be using to find a place to safely put the airplane on the ground while trying to restart the engine (if appropriate).
As you said most props will fail to the low pitch/high RPM positiion -- but they will not go beyond the low pitch stop. The low pitch INCREASES prop RPM so to reduce drag you need to reduce prop RPM which you can do if you still have enough oil/oil pressue to operate the prop.
The T6 Texan II is a turbine which is a completely different animal and not applicable to this conversation.
No I haven't. I've shut down engines on multi-engine aircraft and had an oil leak on a single engine ones but never lost an engine completely.
I think depending on your altitude you might still want to stop the prop. My policy for single engine aircraft is if your above 5K AGL and you can't get your engine to re-start you should stop the prop as it will increase your glide distance. If your bellow 5K AGL then as you said it starts to become dangerous and you wont gain much but stopping to prop so bellow 5K AGL you should keep it windmilling.
I also believe that in order to get your PPL you should be required to demonstrate a clean power off stall with a power off recovery and spins so you would be [more] ready for such situations.
I don't have any experience with turboprops, why is it a different story? You have the same prop, it's just that the thing that's powering it is different but that should not be a factor.
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I think depending on your altitude you might still want to stop the prop. My policy for single engine aircraft is if your above 5K AGL and you can't get your engine to re-start you should stop the prop as it will increase your glide distance. If your bellow 5K AGL then as you said it starts to become dangerous and you wont gain much but stopping to prop so bellow 5K AGL you should keep it windmilling.
I also believe that in order to get your PPL you should be required to demonstrate a clean power off stall with a power off recovery and spins so you would be [more] ready for such situations.
I don't have any experience with turboprops, why is it a different story? You have the same prop, it's just that the thing that's powering it is different but that should not be a factor.
The first time you lose an engine and attempt to stop the prop you're policy will be quickly revised. In something like a J-3, Champ, maybe a 150 or 152 you might be able to get the prop stopped...anything with much higher performance engine or higher stall speed it's not going to happen. Like I said about the 182 and 206...I was on the ground before the prop stopped...at speeds to low to maintain flight.
You should go try your idea before having an actual engine loss. Try it under controlled conditions instead of when it really matters.
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The first time you lose an engine and attempt to stop the prop you're policy will be quickly revised. In something like a J-3, Champ, maybe a 150 or 152 you might be able to get the prop stopped...anything with much higher performance engine or higher stall speed it's not going to happen. Like I said about the 182 and 206...I was on the ground before the prop stopped...at speeds to low to maintain flight.
You should go try your idea before having an actual engine loss. Try it under controlled conditions instead of when it really matters.
I see your point.
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I only try to stop the prop if the huge altitude I lose doing it is offset by my being at 30,000 feet.
Depending on what you are flying and how high you are, there is a certain altitude that stopping the prop gives a longer glide.
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I agree colmbo: I have had 3 engine outs, All i got restarted, but stopping prop was not exactly a thing I would wish to try.
1. Do to inverted flight on wrong tank.
2. Do to spinner explosively departing airplane followed by A shaking I never wish to feel again.
3. Do to mechanical fuel pump fail. Only time I got clearance to fly over center of DFW.
I'm glad I never had to land with no power.
HiTech
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So since you guys disagree with my idea of stopping the prop, what's the point of designing a governor that will not feather the blades when you loose oil pressure?
I can thing of two reasons, making it easier to re-start the engine after it fails and if your governor will fail you will atleast have power. But I don't think those two reasons justify not feathering the prop.
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So since you guys disagree with my idea of stopping the prop, what's the point of designing a governor that will not feather the blades when you loose oil pressure?
I can thing of two reasons, making it easier to re-start the engine after it fails and if your governor will fail you will atleast have power. But I don't think those two reasons justify not feathering the prop.
Those "guys" are actual pilots :aok
I'm no expert but trying to start an engine that "stopped" like you suggest would be a hell of alot harder than if it is already spinning.
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Those "guys" are actual pilots :aok
I'm no expert but trying to start an engine that "stopped" like you suggest would be a hell of alot harder than if it is already spinning.
So am I ;)
And I don't think I ever suggested that you should start an stopped engine. If you want I can clarify what I said but I'm not sure which one of my posts you misunderstood.
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i was thinking more of throttle, rpm, prop pitch, and mixture.
in game the only thing we don't control is mixture.
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how about a sputtering engine... :x :x
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In the book Terror in the Starboard Seat there is a description of a Mossie having both engines shut down due to the crew forgetting to change fuel tanks. In the ensuing period there wasn't any mention of feathering the props, just the frantic efforts to restart the engines, which they did manage. Now I know they weren't very high up and the type of engine outage they had was conducive to restarting the engines, so it may not be a valid event per this thread.
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In the book Terror in the Starboard Seat there is a description of a Mossie having both engines shut down due to the crew forgetting to change fuel tanks. In the ensuing period there wasn't any mention of feathering the props, just the frantic efforts to restart the engines, which they did manage. Now I know they weren't very high up and the type of engine outage they had was conducive to restarting the engines, so it may not be a valid event per this thread.
If your about to re-start it there is no point of feathing the prop. You feather the prop as a last ditch maneuver so if would provide minimal drag after you lost all hope for restarting it.
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the point of this wish post was for the implementation of a new engine damage model with the possibility of engine restart based on the amount of damage inflicted, and possibly more control over aircraft systems, not just the topic of feathering props. :rolleyes:
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my point is that currently the game model is either an oil hit, radiator hit, or a catastrophic engine failure that leaves you with no power. durring the war there were many cases of engine damage to cylinders (particularly radial engines) that would either stall the engine and would need to be restarted, or would allow it to run at a decreased capacity. many a good pilot could restart an engine with some fiddling and get it to run with even chunks missing form the block. i partially dislike all the autimation in the game and would like to see more control over aircraft systems. may be a bit larger learning curve but once you get a hang on it, there would be a lot more to squeeze out of the airframe.
This game is about fighting. Not learning how to get an engine cranked.
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the game is a combat simulator, this includes getting to and from a fight. not just getting there and dying, reup and repeat. a bit arcadeish if you ask me. much better than most other games but still.
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So since you guys disagree with my idea of stopping the prop, what's the point of designing a governor that will not feather the blades when you loose oil pressure?
You'd have to ask the designer that question.
I've heard/thought it is to allow the prop to provide at least some thrust in the event of loss of oil to the prop hub. Some props fail to the high pitch/low RPM end which would be better drag wise in the event of and engine failure.
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If your about to re-start it there is no point of feathing the prop. You feather the prop as a last ditch maneuver so if would provide minimal drag after you lost all hope for restarting it.
Or to keep the prop from running away (Not applicable to modern light aircraft).as you make a circuit and land. Works the non-flying pilots hand out as he pops the feather button in and out to control RPM. Fun times. :lol
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Right
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the game is a combat simulator, this includes getting to and from a fight. not just getting there and dying, reup and repeat. a bit arcadeish if you ask me. much better than most other games but still.
Would you really like to limit your self to one plane?
You'd have to memorize so much stuff for that specific plane that chances are you would not be flying anything else.
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im sure aces high would implement it in a more universal form such as for radials and inline v's, for cowl flaps and radiator flaps. other than that i cant see any other variations except for changes in mixture and rpm sweet spots which could be put on the e6b tab for each plane along with the data currently there.
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im sure aces high would implement it in a more universal form such as for radials and inline v's, for cowl flaps and radiator flaps. other than that i cant see any other variations except for changes in mixture and rpm sweet spots which could be put on the e6b tab for each plane along with the data currently there.
That doesn't sound like a "simulation" now does it?
wrongway
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im sure aces high would implement it in a more universal form such as for radials and inline v's, for cowl flaps and radiator flaps. other than that i cant see any other variations except for changes in mixture and rpm sweet spots which could be put on the e6b tab for each plane along with the data currently there.
First the type on engines would require completely different operations. Now even if you still fly airplanes with the same engines you will have to memorize flap speeds for each airplane.
I can't list everything from the top of my head but there will be a lot of stuff that you will need to memorize.
Also, you said you want mixture. Do you know how it works, right?
You will need to chance your mixture setting with altitude, in other words while while your dogfighting you will need to be continuesky changing your altitude settings as you climb and decend. Maximum mixture does not mean maximum power.
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oh i do know! im not just talking out of my arse about something i have no clue about. and i do understand that with each plane there are differences in system but hasn't a general operation already been implemented thruought the planeset already? take combat trim for instance. there is an option to turn it on and let it do its own thing trimming and all, but does it give you a perfect trim all the time? why not allow for turning on assists to HELP but not do it all for you. besides, when has a dogfight ever drastically changed in altitude where it would severely disrupted engine preformance? other than a headlong dive into a fight for bnz or when your turning and losing alt, the mixture is only going to richen slightly which can be let go until there is a lul, as would an actual fighter pilot would do. as for difference in operation in engine type, they all have the same basic principals between each type of engine setup. i dont mean get down into the nitty gritty and put in every single switch and dial there was in the actual planes, just the general systems operations that every plane would have but have slight differences in say, cowl flaps or if the plane use a double or single stage supercharger and such. as for flap speeds, the autimatically go up when going over their max ias, leave em that way, we already have control over them, but with a safety mechanism to prevent accidental damage.
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The thing is that if you add that stuff there will be plenty of people who will not play. HiTech already said its not going to happen because AH is about combat, not aircraft operations.
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my mates dad had to restart his vulcan in the early 70s after they accidentally switched over to empty tanks somewhere over the north sea. cost them ~5,000' and new underwear all round. iirc they kept quiet about it :uhoh
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So far i havn't seen a post by Hitech denouncing my idea so far but in total, all additional controls to be added would be roughly 3 or 4 more with a bit more realistic engine damage engine. certainly not enough to make the game all about aircraft operation and skip the combat. and with optional assist tabs, like the auto takeoff or stall limiter for the newbs, what would make flying all that more difficult? it would be a welcome sight to those that enjoy a bit more realism in this much beloved combat sim.
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So far i havn't seen a post by Hitech denouncing my idea so far but in total, all additional controls to be added would be roughly 3 or 4 more with a bit more realistic engine damage engine. certainly not enough to make the game all about aircraft operation and skip the combat. and with optional assist tabs, like the auto takeoff or stall limiter for the newbs, what would make flying all that more difficult? it would be a welcome sight to those that enjoy a bit more realism in this much beloved combat sim.
I agree with you, but it's just not going to happen. Most people here know nothing about aircraft operations and certainly would not like it to be more complex, we don't have wind for the same reason.
This has been discussed a thousand times before, in one of the older threads HiTech said that he wants AH to be about air combat, not aircraft operations. If you want I can try finding that quote for you, but that will be later in the day.
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my mates dad had to restart his vulcan in the early 70s after they accidentally switched over to empty tanks somewhere over the north sea. cost them ~5,000' and new underwear all round. iirc they kept quiet about it :uhoh
You mean the Avro Vulcan?
I can't imagine what it would be like to loose all your four engines at the same time.
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yup he flew canberras for years then moved into vulcans. the conversation was almost 20yr ago after dinner and tbh I'd had a coupla beers and he'd had a bottle or 2 of claret and a few cognacs ;)
I assume it was all 4 engines because he said they lost the engines and power one at a time in about 30s. they assumed it was an electrical system problem and after running through the procedures noticed the fuel settings, rerouted the tanks and restarted. he said it felt like 15mins til they had the engines back up but was probably more like 60s due to the effects of adrenaline and so much training you can blast through a checklist even though you cant even remember your own name ... iirc he said the vulcan had a very complex fuel system with a bunch of tanks that you can reroute to any of the engines.
edit: the weird thing is my mates dad was the first officer on that flight. a few years later my dad discovered that one of his new bosses knew my mates dad, from his RAF days as it happened. it turned out my dads boss was the pilot!
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So since you guys disagree with my idea of stopping the prop, what's the point of designing a governor that will not feather the blades when you loose oil pressure?
It has nothing do to with governor design. But rather the internals workings of the prop, the max degree of rotation of the blades is limited by the distance the piston can travel. Looking at most Hartells they work similar to a piston and crank shaft setup where the movement of the piston is attached to a push rod attached to the outside of the prop. Oil and spring, or oil and counter weight turn the blades. Making these work to the degree needed for feather is more complex and heaver. Hence only put on multi engine planes.
On a multi where you loose and engine it is very desirable to minimize drag since you can maintain flight with the lost engine. With single engine the trade off is not worth it.
There are also other trade offs. For instance most single engine constant speed props use oil presure to increase blade angle and a spring to decrees the angle. This has the effect of loss of oil pressure flattens the prop I.E. High rpm. For normal planes the only time you loose pressure , the odds are your engine is also not running. Or you can just pull power back. I.E it is only in an emergency situation.
When flying aerobatics with and inverted oil systems, there are conditions where when flying in the vertical at zero g the valve can get stuck temporally between inverted and normal flight, hence starving the engine of oil. When at full power loss of oil pressure would cause prop to go flat, and almost instantly over rev the engine. Hence aero props work with counter weights to increase pitch and oil pressure to decrease pitch. So in the case loss of oil pressure, loads down the engine which is the much more desirable case.
Ive heard the engine load down in my rv a few times in the vertical zoom part of a hammer head.
So to answer your question why not make all. It is just like any part of aircraft design. There is not any one best design. It always has to do with tradeoffs , and what is most important in any particular usage.
HiTech
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See I always knew that the internal components of the prop that on a multi engine are heavier, but is it significant? The only extra parts that you have are the counterweights, those weigh around 1-2lb.
Ive heard the engine load down in my rv a few times in the vertical zoom part of a hammer head.
So when you zoom up the prop is not capable of compensating and the RPMs decrease?
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yup he flew canberras for years then moved into vulcans. the conversation was almost 20yr ago after dinner and tbh I'd had a coupla beers and he'd had a bottle or 2 of claret and a few cognacs ;)
I assume it was all 4 engines because he said they lost the engines and power one at a time in about 30s. they assumed it was an electrical system problem and after running through the procedures noticed the fuel settings, rerouted the tanks and restarted. he said it felt like 15mins til they had the engines back up but was probably more like 60s due to the effects of adrenaline and so much training you can blast through a checklist even though you cant even remember your own name ... iirc he said the vulcan had a very complex fuel system with a bunch of tanks that you can reroute to any of the engines.
edit: the weird thing is my mates dad was the first officer on that flight. a few years later my dad discovered that one of his new bosses knew my mates dad, from his RAF days as it happened. it turned out my dads boss was the pilot!
I see.
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See I always knew that the internal components of the prop that on a multi engine are heavier, but is it significant? The only extra parts that you have are the counterweights, those weigh around 1-2lb.
Not all props have counter-weights. Some of the added weight will be an accumulator, or other system, that can be used to un-feather the engine. On the B-17 and B-24 the props were feathered by using of a "feathering pump". Simply an electric pump used to pump oil into the hub to drive the blades into the feather positiion. It was also used to unfeather. The oil reservoir was set up with a sump below the oil line to preserve enough oil to feather if an oil line to the engine was cut/broken/leaking.
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Not all props have counter-weights. Some of the added weight will be an accumulator, or other system, that can be used to un-feather the engine. On the B-17 and B-24 the props were feathered by using of a "feathering pump". Simply an electric pump used to pump oil into the hub to drive the blades into the feather positiion. It was also used to unfeather. The oil reservoir was set up with a sump below the oil line to preserve enough oil to feather if an oil line to the engine was cut/broken/leaking.
Right, I forgot about the accumulator.
How can you have a prop with no counter-weights that will feather due to lack of oil pressure?
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See I always knew that the internal components of the prop that on a multi engine are heavier, but is it significant? The only extra parts that you have are the counterweights, those weigh around 1-2lb.
So when you zoom up the prop is not capable of compensating and the RPMs decrease?
Yes , the prop gets starved of oil for a brief period of time. And hence goes full course pitch. As mentioned above the other way to solve the issue is with a pressure accumulator, most I have seen have a nitrogen bladder that oil is pumped into compressing the air, then when the valve gets stuck in the middle there is enough reservoir feeding the prop. I have only seen these on planes that have a non areo prop. But not sure if they are used in others.
HiTech
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Right, I forgot about the accumulator.
How can you have a prop with no counter-weights that will feather due to lack of oil pressure?
I don't know of any prop that will feather without oil pressure unless it's an electric hub. McCauley's use a spring that drives the blades to low pitch in the event of no oil pressure. Hitech stated his prop is driven to the high pitch stop with no oil pressure. Counter-weights just produce a force to drive the blade in one direction, the oil pressure is used to work against the counter-weights (or springs).
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On the subject of damage, what has happened to the plans to work the more detailed World War I model into World War II?
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I don't know of any prop that will feather without oil pressure unless it's an electric hub. McCauley's use a spring that drives the blades to low pitch in the event of no oil pressure. Hitech stated his prop is driven to the high pitch stop with no oil pressure. Counter-weights just produce a force to drive the blade in one direction, the oil pressure is used to work against the counter-weights (or springs).
Right, that what I thought.
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Yes , the prop gets starved of oil for a brief period of time. And hence goes full course pitch. As mentioned above the other way to solve the issue is with a pressure accumulator, most I have seen have a nitrogen bladder that oil is pumped into compressing the air, then when the valve gets stuck in the middle there is enough reservoir feeding the prop. I have only seen these on planes that have a non areo prop. But not sure if they are used in others.
HiTech
Hmm, I see.
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The first time you lose an engine and attempt to stop the prop you're policy will be quickly revised. In something like a J-3, Champ, maybe a 150 or 152 you might be able to get the prop stopped...anything with much higher performance engine or higher stall speed it's not going to happen. Like I said about the 182 and 206...I was on the ground before the prop stopped...at speeds to low to maintain flight.
You should go try your idea before having an actual engine loss. Try it under controlled conditions instead of when it really matters.
BTW about a year ago I did this test in AH and the results showed that stopping the prop would be a good idea. Granted the type of aircraft is a little different, but what do you think about this?
I made a series of tests today to figure out Spit14's best glide speed. I took a Spit14 with 50% fuel and used the SW spawn at A22 in the training arena. Prop RPMs were set to minimum.
TEST 1: Used 175mph for the first test (HTC's programed autoclimb speed for Spit14). After landing, I asked someone to serve as a reference point for my further tests. Had him put his airplane right where my is in order to measure distance for further tests.
TEST 2: 200mph, landed 5K before the reference point.
TEST 3: 165mph, landed 3.1K after the reference point.
TEST 4: 140mph, landed 3.3K after the reference point.
TEST 5: 130mph, landed 3.3K after the reference point.
TEST 6: 135mph, landed 3.8K after the reference point.
135 mph is the best glide speed for Spitfire mk XIV is this configuration.
I know in reality the plane will glide further with prop stopped than feathered. So I decided to test if HTC implemented this in AH.
TEST 7: Used the same 135mph as before. With the engine ignition off I had pitch up and reduce my airspeed beyond stall to 20mph which caused the airplane to climb another 2000ft, then since the airplane was already in the stall I had to dive down to initial altitude to recover from the stall. Then I continued the glide. I landed beyond 6K from the reference point so I do not know the exact distance. Since in test 6 I landed 3.8K from the reference point I this test proves that the plane glides better with the prop stopped. Additionally in test 6 I overflew the reference point at 2000ft MSL, in test 7 I overflew the reference point at 4000ft MSL, which additional proves that gliding with prop stopped results in a longer & more efficient climb.
This demonstrates that the energy lost due to maneuvering to get the prop to stop can pay of assuming that the glide is from a relatively high altitude.
Note: It will not necessarily pay off if the glide is from a low altitude.
WARNING: DO NOT DO THIS AT LOW ALTITUDE AS YOU MAY NOT RECOVER FROM THE STALL.
Special thanks to Electric for dedicating his time acting as a reference point.
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Granted the type of aircraft is a little different, but what do you think about this?
I agree that there is less drag with a stopped prop. No doubt.
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Springs and gears......many props use them instead of rods and levers.
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im sure aces high would implement it in a more universal form such as for radials and inline v's, for cowl flaps and radiator flaps. other than that i cant see any other variations except for changes in mixture and rpm sweet spots which could be put on the e6b tab for each plane along with the data currently there.
For airport type flight try M$FS. No one here wants to sit on the runway while a cap is on and go through a checklist. No flipping magnetos, no setting cowl flaps, no runups.
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engine damage! ya get hit and it dies. what do you do? glide as far as you can and crash land. but what if you could attempt to restart the engine? through a series of engine control manipulations to say find a 'sweet spot' where it will restart and run at say half power? or at a lower power based on the amount of damage? would be neat to be able to at least try to limp home. possibly also have the option to feather the prop if need be? could be exciting! :joystick:
That's one of the fun things of AH, you don't know if you'll even be flying home, or what condition your plane is in. We can curse the game for not crediting us with getting a half-engined, half-winged, half-tailed, bleeding aircraft 25-ft. off the runway and with 6 kills in the bank, but I'm content.
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I agree that there is less drag with a stopped prop. No doubt.
Roger