stall
- Thread starter greycap
- Start date
In real life stall speed is based on many different factors. I assume in the FS2004 the stall speed is calculated from different factors like weight, point of gravity, wing surface, and inputs like flaps under carriage etc.
Therefore I consider it unlikely that there is a single parameter which can be used to manipulate stall speed.
Cheers,
Huub
Therefore I consider it unlikely that there is a single parameter which can be used to manipulate stall speed.
Cheers,
Huub
hi I don't know the real stall speeds . the aircraft in question are : wop 190s, and p47 . and recently the twin mustang that I got the changed air and cfg files from soh .
Greycap,
I have the feeling that we went trough this discussion already in October last year.
The combination of the model, .air file and aircraft configuration file determine how a model behaves in the flight simulator. The flight dynamics files consist of a large amount of parameters which the combination of these parameter will make a model behave in FS2004 as it does.
The configuration and air file for the Twin Mustang were made from scratch by Fliger747 as the original file which can with the model, were miles away from how the original flew, or even from how an ordinary plane flies.
The WOP P-51 and P-47 are most probably close enough to how people expect the real aircraft flew, as nobody took the effort to make new configuration and air files for these models. (At least as far as I know).
So flying carefully of putting your reality sliders from FS2004 to simple is the only solution I can offer.
Cbeers,
Huub
I have the feeling that we went trough this discussion already in October last year.
The combination of the model, .air file and aircraft configuration file determine how a model behaves in the flight simulator. The flight dynamics files consist of a large amount of parameters which the combination of these parameter will make a model behave in FS2004 as it does.
The configuration and air file for the Twin Mustang were made from scratch by Fliger747 as the original file which can with the model, were miles away from how the original flew, or even from how an ordinary plane flies.
The WOP P-51 and P-47 are most probably close enough to how people expect the real aircraft flew, as nobody took the effort to make new configuration and air files for these models. (At least as far as I know).
So flying carefully of putting your reality sliders from FS2004 to simple is the only solution I can offer.
Cbeers,
Huub
thanks again for your time. October seems a long time ago with the words currant problems
greycap
Motormouse
SOH-CM-2024
in the .cfg file you can change the reference speeds, but won't have a lot of effect unless the .air file is adjusted to suit
ttfn
Pete
Code:
[Reference Speeds]
flaps_up_stall_speed=99.800
full_flaps_stall_speed=88.900
cruise_speed=270.000
max_indicated_speed=435ttfn
Pete
srgalahad
Charter Member 2022
Actually...
An aircraft, or more correctly the wing(s) stalls due to angle of attack. There is no one fixed speed so you can't really manipulate the 'performance' of the aircraft to prevent it.
"Stalls depend only on angle of attack, not airspeed However, the slower an aircraft flies, the greater the angle of attack it needs to produce lift equal to the aircraft's weight. As the speed decreases further, at some point this angle will be equal to the critical (stall) angle of attack. This speed is called the "stall speed".
https://en.wikipedia.org/wiki/Stall_(fluid_dynamics)
In a loop, the critical angle is exceeded at some point and the wing is "stalled" but momentum carries you through until the wing exits the condition and lift is regained. There is a point around the point of inversion where the wing produces some small lift even though upside down but it's not sustainable as airspeed continues to decay. Therefore, the only way to not stall AND fall out of the loop is to have sufficient speed (energy) to carry you though the period of loss of lift. Initially pulling too slowly will decay your airspeed too soon and you stall,. Pulling too hard initiates a dynamic stall (see the wiki article) and the same result occurs at a different time.
In a flat turn the angle of bank determines how soon you reach the critical angle of attack (bearing in mind that dihedral will change how soon that onset happens as one wing stalls before the other). So again, energy management is key. you can maintain it only so long before loss of lift becomes final. In aircraft with a high power/weight ratio (like the Extra 300) it may look like there's no change but you have to increase yaw to maintain (briefly) a constant altitude. A small amount of lift is produced by the fuselage in some cases and by the vertical fin - until it too reaches its critical angle of attack, then - poof. BTW, those You Tube videos of crazy knife-edge flights in RC models are dependant on P/W ratios far in excess of real aircraft.
Any mods to the aircraft flight dynamics to prevent or reduce the stall characteristics may have a serious negative effect on how the aircraft behaves in 'normal' flight because you are effectively changing the shape of the parts (in an aerodynamic sense).
I posit that if the model flies incorrectly through most of the flight regime, then it probably needs an overall fix (like the P-82 which I flew a lot in FS9 before and after Tom's mods). If the aircraft behaves well in normal flight modes then it's not the model, but pilot technique that needs attention. Note that some aircraft are not good aerobatic aircraft and the sim can make it worse. Test entry speeds over a range and you'll see where it works.. too fast and your pitch can overstress the model; too slow and you'll lack the energy. Make notes. Also watch your weights!
Most of my references are stored away, but from memory I would guess that the Jug was not a great a/c to try to loop - high entry speed or a too-rapid loss of energy.
An aircraft, or more correctly the wing(s) stalls due to angle of attack. There is no one fixed speed so you can't really manipulate the 'performance' of the aircraft to prevent it.
"Stalls depend only on angle of attack, not airspeed However, the slower an aircraft flies, the greater the angle of attack it needs to produce lift equal to the aircraft's weight. As the speed decreases further, at some point this angle will be equal to the critical (stall) angle of attack. This speed is called the "stall speed".
https://en.wikipedia.org/wiki/Stall_(fluid_dynamics)
In a loop, the critical angle is exceeded at some point and the wing is "stalled" but momentum carries you through until the wing exits the condition and lift is regained. There is a point around the point of inversion where the wing produces some small lift even though upside down but it's not sustainable as airspeed continues to decay. Therefore, the only way to not stall AND fall out of the loop is to have sufficient speed (energy) to carry you though the period of loss of lift. Initially pulling too slowly will decay your airspeed too soon and you stall,. Pulling too hard initiates a dynamic stall (see the wiki article) and the same result occurs at a different time.
In a flat turn the angle of bank determines how soon you reach the critical angle of attack (bearing in mind that dihedral will change how soon that onset happens as one wing stalls before the other). So again, energy management is key. you can maintain it only so long before loss of lift becomes final. In aircraft with a high power/weight ratio (like the Extra 300) it may look like there's no change but you have to increase yaw to maintain (briefly) a constant altitude. A small amount of lift is produced by the fuselage in some cases and by the vertical fin - until it too reaches its critical angle of attack, then - poof. BTW, those You Tube videos of crazy knife-edge flights in RC models are dependant on P/W ratios far in excess of real aircraft.
Any mods to the aircraft flight dynamics to prevent or reduce the stall characteristics may have a serious negative effect on how the aircraft behaves in 'normal' flight because you are effectively changing the shape of the parts (in an aerodynamic sense).
I posit that if the model flies incorrectly through most of the flight regime, then it probably needs an overall fix (like the P-82 which I flew a lot in FS9 before and after Tom's mods). If the aircraft behaves well in normal flight modes then it's not the model, but pilot technique that needs attention. Note that some aircraft are not good aerobatic aircraft and the sim can make it worse. Test entry speeds over a range and you'll see where it works.. too fast and your pitch can overstress the model; too slow and you'll lack the energy. Make notes. Also watch your weights!
Most of my references are stored away, but from memory I would guess that the Jug was not a great a/c to try to loop - high entry speed or a too-rapid loss of energy.
Sbob
SOH-CM-2024
^ Another way to think of this is "Most of my references are stored above my seat cushion". 
This is the whole idea of flying by the seat of your pants. Get to know the airplane, figure out its strengths and weaknesses. In most cases, figure out what you're doing wrong.
I logged a lot of time in Alphasim's B-52. Both Alphasim and Capt. Sim caught a lot of flack for their B-52s, they just didn't fly right.
As it turned out, the Alphasim flight dynamics were VERY good and accurate. The trouble was that you can't fly a B-52 like a four seat Cessna or a 737 or an F-15.
I would see folks trying to take off with "one click of flaps" deployed and 100% fuel (flaps need to be either fully stowed or fully deployed, the flight model is also VERY weight dependent and 100% fuel is ONLY used in certain situations after aerial refueling ). The problem wasn't the flight dynamics, it was how folks were trying to fly the plane.
For the most part, the only parts of the dynamics I'll tweak are the stall ALARM and overspeed alarm set points. You can find these values in the .air file in section 1101 and also just above 1101. These two alarm values are very simplistic compared to the rest of the flight dynamics and the only thing they control is when the messages flash up and the alarms go off.
Even then, I don't change the values a lot. Usually, I'll set them 2 to 5 knots faster or slower so the alarms go off just before I get into trouble.
BTW, don't worry if it sounds like I'm being critical. We're supposed to be critical of ourselves after every flight. Its how we build experience and get better.
This is the whole idea of flying by the seat of your pants. Get to know the airplane, figure out its strengths and weaknesses. In most cases, figure out what you're doing wrong.
I logged a lot of time in Alphasim's B-52. Both Alphasim and Capt. Sim caught a lot of flack for their B-52s, they just didn't fly right.
As it turned out, the Alphasim flight dynamics were VERY good and accurate. The trouble was that you can't fly a B-52 like a four seat Cessna or a 737 or an F-15.
I would see folks trying to take off with "one click of flaps" deployed and 100% fuel (flaps need to be either fully stowed or fully deployed, the flight model is also VERY weight dependent and 100% fuel is ONLY used in certain situations after aerial refueling ). The problem wasn't the flight dynamics, it was how folks were trying to fly the plane.
For the most part, the only parts of the dynamics I'll tweak are the stall ALARM and overspeed alarm set points. You can find these values in the .air file in section 1101 and also just above 1101. These two alarm values are very simplistic compared to the rest of the flight dynamics and the only thing they control is when the messages flash up and the alarms go off.
Even then, I don't change the values a lot. Usually, I'll set them 2 to 5 knots faster or slower so the alarms go off just before I get into trouble.
BTW, don't worry if it sounds like I'm being critical. We're supposed to be critical of ourselves after every flight. Its how we build experience and get better.
In the simulator Stall speed comes from Table 404 in the .air file.
Modifying this table can wonk out a whole lot of other variables in flight.
Modifying this table can wonk out a whole lot of other variables in flight.
a
hi
air files are beyond me. I have ,in cfg, taken out of weight guns, ammo, rockets and bombs and 300 lbs off lift moi DROPPED 70% OF FUE,L ADDED 20% of power and it now flies like the one I have seen at air shows.i need to drop the power down a bit as it takes off like a storch . its more comfortable for my type of flying
hi
air files are beyond me. I have ,in cfg, taken out of weight guns, ammo, rockets and bombs and 300 lbs off lift moi DROPPED 70% OF FUE,L ADDED 20% of power and it now flies like the one I have seen at air shows.i need to drop the power down a bit as it takes off like a storch . its more comfortable for my type of flying