Aircraft Rotation Speed
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TKMR
- Posts: 29
- Joined: 2008-04-06 17:06
Aircraft Rotation Speed
Today while playing the map Battle for Qinling, I entered a J10 in order to provide my squad some air support. I taxied out to the Runway, Lined, up, waited a second, and started to take off. Once I got to about 800Kts (Or Km/H whatever the game uses)I attempted to rotate my plane (Takeoff). I, however, realized that my plane wasn't taking off...
This is horribly unrealistic for several reasons. A: If the speeds are in Kts then I was at about Mach 1.5. If the speeds are in Km/H I was nearly at Mach 2. B: The rotation speed of a 747 is about 180 Kts @ 10-20 Degree flaps. Even fully loaded a J10 will not weigh nearly as much as a 747. Taking into account the fact that the J10 only has one engine, even though that engine produces nearly as much thrust as two 747 engines, the J10 should have a rotation speed of no more than 200 kts.
I understand the need, and want, to keep the "noobs" out of the assets such as the planes, but you are afterall trying to be as realistic as possible, and a rotation speed above the speed of sound is completely unrealistic.
This also brings me to another point, the speed of the A10, and Su25. I was flying at approximately 1400Kts, or Km/H. There is now way EITHER of these planes could go THIS fast. They are very slow planes, and normally fly at approximately 200-400Kts (Cruising).
I just wanted to bring these things to your attention.
This is horribly unrealistic for several reasons. A: If the speeds are in Kts then I was at about Mach 1.5. If the speeds are in Km/H I was nearly at Mach 2. B: The rotation speed of a 747 is about 180 Kts @ 10-20 Degree flaps. Even fully loaded a J10 will not weigh nearly as much as a 747. Taking into account the fact that the J10 only has one engine, even though that engine produces nearly as much thrust as two 747 engines, the J10 should have a rotation speed of no more than 200 kts.
I understand the need, and want, to keep the "noobs" out of the assets such as the planes, but you are afterall trying to be as realistic as possible, and a rotation speed above the speed of sound is completely unrealistic.
This also brings me to another point, the speed of the A10, and Su25. I was flying at approximately 1400Kts, or Km/H. There is now way EITHER of these planes could go THIS fast. They are very slow planes, and normally fly at approximately 200-400Kts (Cruising).
I just wanted to bring these things to your attention.
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Mora
- Posts: 2933
- Joined: 2007-08-21 12:37
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markonymous
- Posts: 1358
- Joined: 2007-10-25 05:20
800 kmh is not mach 2... more like mach 0.75 and i allmost always take off around 400-500 dont know why you couldnt take off at 800.TKMR wrote:Today while playing the map Battle for Qinling, I entered a J10 in order to provide my squad some air support. I taxied out to the Runway, Lined, up, waited a second, and started to take off. Once I got to about 800Kts (Or Km/H whatever the game uses)I attempted to rotate my plane (Takeoff). I, however, realized that my plane wasn't taking off...
This is horribly unrealistic for several reasons. A: If the speeds are in Kts then I was at about Mach 1.5. If the speeds are in Km/H I was nearly at Mach 2. B: The rotation speed of a 747 is about 180 Kts @ 10-20 Degree flaps. Even fully loaded a J10 will not weigh nearly as much as a 747. Taking into account the fact that the J10 only has one engine, even though that engine produces nearly as much thrust as two 747 engines, the J10 should have a rotation speed of no more than 200 kts.
I understand the need, and want, to keep the "noobs" out of the assets such as the planes, but you are afterall trying to be as realistic as possible, and a rotation speed above the speed of sound is completely unrealistic.
This also brings me to another point, the speed of the A10, and Su25. I was flying at approximately 1400Kts, or Km/H. There is now way EITHER of these planes could go THIS fast. They are very slow planes, and normally fly at approximately 200-400Kts (Cruising).
I just wanted to bring these things to your attention.
im not sure but i've been told that the speedometer is fake in bf2.

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unlocks_r_emo
- Posts: 39
- Joined: 2007-12-23 10:11
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TKMR
- Posts: 29
- Joined: 2008-04-06 17:06
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CAS_117
- Posts: 1600
- Joined: 2007-03-26 18:01
1. The speeds are in BS. You're actually going 1700 BS units = 247 kts.This is horribly unrealistic for several reasons. A: If the speeds are in Kts then I was at about Mach 1.5. If the speeds are in Km/H I was nearly at Mach 2. B: The rotation speed of a 747 is about 180 Kts @ 10-20 Degree flaps. Even fully loaded a J10 will not weigh nearly as much as a 747. Taking into account the fact that the J10 only has one engine, even though that engine produces nearly as much thrust as two 747 engines, the J10 should have a rotation speed of no more than 200 kts.
2. "Rotate"? Why do you like that word so much? First of all you don't measure rotation speed (velocity about an arc at a given point) in kts.
3. Engines are heavy, having two doesn't make you any lighter. Everything about a plane can be changed except for weight. Once you put it on you can't just give it bigger wings and more fuel, cause then you need a bigger engine(s). Which is how the F-111 became the tragedy that it was.
4. I'm sorry I just cannot for the life of me understand what you mean by "rotate". The planes rotate in the sense of pitch, roll, and yaw, but you can't "rotate" in a straight line.I understand the need, and want, to keep the "noobs" out of the assets such as the planes, but you are afterall trying to be as realistic as possible, and a rotation speed above the speed of sound is completely unrealistic.
5. The planes are retardedly easy to fly. Theres no real gravity (try going into a dive or climb and you'll notice something strange), wind, and no real avionics other than the altimeter and compass (stupid speedometers aside). So I can't really say that flying is particularly difficult in PR atm. I've made a way to intensify the force of gravity and drag but its still the BF2 engine.
*REMEMBER
Pulling up = Drag.
Drag = < speed
< speed = < altitude
< altitude = 20 minutes wasted
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Masaq
- Retired PR Developer
- Posts: 10043
- Joined: 2006-09-23 16:29
CAS, "rotate" is the term used when pulling back on the stick during takeoff; he's using quite correct terminology. Rotation speed is the speed at which the pilot can begin to rotate the aircraft's nose into the air, and is defined as Vr. Suprised you didn't know that, and suprised you didn't google it too 
Original poster - CAS is right in that the speeds in the game are completely and utterly bunk; pay no heed to them at all!
Original poster - CAS is right in that the speeds in the game are completely and utterly bunk; pay no heed to them at all!
"That's how it starts, Mas, with that warm happy feeling inside. Pretty soon you're rocking in the corner, a full grown dog addict, wondering where your next St Bernand is coming from..." - IAJTHOMAS
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AlphaBravo
- Posts: 22
- Joined: 2008-03-29 19:05
Takeoff - Wikipedia, the free encyclopediaThe takeoff speed required varies with air density, aircraft gross weight, and aircraft configuration (flap and/or slat position, as applicable). Air density is affected by factors such as field elevation and air temperature. This relationship between temperature, altitude, and air density can be expressed as a density altitude, or the altitude in the International Standard Atmosphere at which the air density would be equal to the actual air density.
Pilots of large multi-engine aircraft calculate a decision speed (V1) for each takeoff that dictates action to be taken in case an engine fails. This speed is determined not only by the above factors affecting takeoff performance, but by the length of the runway and any peculiar conditions, such as obstacles off the end of the runway. Below V1, the takeoff is aborted; above V1 the pilot continues the takeoff and returns for landing. After the co-pilot calls V1, he/she will call Vr or "rotate," marking speed at which to rotate the aircraft. The Vr for transport category aircraft is computed such that three seconds after rotation is initiated the aircraft is in the liftoff attitude and at the liftoff speed. Then, V2 (the safe climb speed) is called. This speed must be maintained to meet performance targets for rate of climb and angle of climb.
In a single-engine or light twin-engine aircraft, the pilot calculates the length of runway required to take off and clear any obstacles, to ensure sufficient runway to use for takeoff. A safety margin can be added to provide the option to stop on the runway in case of a rejected takeoff. In most such aircraft, any engine failure results in a rejected takeoff as a matter of course, since even overrunning the end of the runway is preferable to lifting off with insufficient power to maintain flight.
If an obstacle needs to be cleared, the pilot climbs at the speed for maximum climb angle (Vx), which results in the greatest altitude gain per unit of horizontal distance travelled. If no obstacle needs to be cleared, or after an obstacle is cleared, the pilot can accelerate to the best rate of climb speed (Vy), where the aircraft will gain the most altitude in the least amount of time. Generally speaking, Vx is a lower speed than Vy, and requires a higher pitch attitude to achieve.
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TKMR
- Posts: 29
- Joined: 2008-04-06 17:06
In the case of the speeds then: If they can be changed to represent knots that would be amazing. I don't even try to do anything with my aircraft until I'm at 170Kts. If I'm flying down the runway and my speed indicator is at 800, and my aircraft isn't in the air, you know there's something wrong... If the nose of the aircraft is barely pitching up at 900, then you know your dead. This was just completely a waste of my time, my teams asset, and my squads lives (since I couldn't get them airsupport).
Also: Some sort of flaps system would be absolutely awesome. Makes it much easier to fly the aircraft at low speeds. I know in 1942 the aircraft had flaps that went up and down with the landing gear, AFAIK they were just an animation and had nothing to do with the way the aircraft handled.
And you're right in saying Flying in PR is pretty easy ATM. The only difficult things are taking off and landing, especially with the screwy speeds.
Leo - That's a good change from BF2V then. =)
Also: Some sort of flaps system would be absolutely awesome. Makes it much easier to fly the aircraft at low speeds. I know in 1942 the aircraft had flaps that went up and down with the landing gear, AFAIK they were just an animation and had nothing to do with the way the aircraft handled.
And you're right in saying Flying in PR is pretty easy ATM. The only difficult things are taking off and landing, especially with the screwy speeds.
Leo - That's a good change from BF2V then. =)
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CAS_117
- Posts: 1600
- Joined: 2007-03-26 18:01
Yeah you've pretty much got it. The delta wings are basically built backward from conventional wing-tail aircraft, so getting them to take off was... problematic. Getting them into a condition that made them pleasant to fly? Didn't really have time for it you see. I'll fix it for 0.8.TKMR wrote:Also: Some sort of flaps system would be absolutely awesome. Makes it much easier to fly the aircraft at low speeds. I know in 1942 the aircraft had flaps that went up and down with the landing gear, AFAIK they were just an animation and had nothing to do with the way the aircraft handled.
And you're right in saying Flying in PR is pretty easy ATM. The only difficult things are taking off and landing, especially with the screwy speeds.
Leo - That's a good change from BF2V then. =)
I think "pitch", "lift", or "raise", (anything pertaining to the vertical axis) would have been more clear I more or less understood your meaning, but not the wording.CAS, "rotate" is the term used when pulling back on the stick during takeoff; he's using quite correct terminology.
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TKMR
- Posts: 29
- Joined: 2008-04-06 17:06
I haven't flown the Eurofighter yet, nor the F16/18. So I can't say about them, but that deffinately surprised me when taking off in the J10, I just hit the fence... and I was like... "Uhhh... WTF?!"
It may just have been the really short runway on that map, but... yeah. I look forward to see the changes. =)
It may just have been the really short runway on that map, but... yeah. I look forward to see the changes. =)
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Warmagi
- Posts: 299
- Joined: 2007-09-17 12:14
Correct me if Im wrong but isnt MACH is something close or actually is a speed of sound? about a 1000 km/h depending on air pressure? so how 800 km/h is a mach 2?
Second I highly doubt that the readings in BF2 engine are correct.
EDIT
ost delay... my reply should have been actually the first one 
Second I highly doubt that the readings in BF2 engine are correct.
EDIT
[R-MOD]Mongolian_dude: ...remember to show as much respect to the new players as the veteran players. Todays 'noob' is tomorrow's 'Vet'.
Reddish_Red: We're fine...
Random.. ehmmm... "player": Give me the chopper. No. I want to fly. No. But I want to, get out from it now or I TK you. ... ... ... No
Reddish_Red: We're fine...
Random.. ehmmm... "player": Give me the chopper. No. I want to fly. No. But I want to, get out from it now or I TK you. ... ... ... No
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Leo
- Posts: 2082
- Joined: 2006-11-29 00:40
Does that mean the J-10 will stop handling like a drugged up heifer?[R-CON]CAS_117 wrote:Yeah you've pretty much got it. The delta wings are basically built backward from conventional wing-tail aircraft, so getting them to take off was... problematic. Getting them into a condition that made them pleasant to fly? Didn't really have time for it you see. I'll fix it for 0.8.
I think "pitch", "lift", or "raise", (anything pertaining to the vertical axis) would have been more clear I more or less understood your meaning, but not the wording.
Right now: EF2000>>>>>>Z-10>>>>>Apache>>>>>Armor>>>>>Foot Soldier>>>>>Rock>>>>>Tree Stump>>>>>>J-10
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CAS_117
- Posts: 1600
- Joined: 2007-03-26 18:01
...Ok to be honest I haven't had any trouble taking off with the J-10. I'll make it easier if thats what people want but I'm not sure what it is people are doing with it right now.
Taking off for me:
1. Throttle 100%
2. Once I'm moving I hit burners (you're runway is pretty short and theres that annoying fence there for some reason).
3. I usually get to 800-900 before taking off.
4. Once past 800 I pitch back on the stick, once I'm pointing up I reengage burners.
Look the J-10 is harder to get off the ground than most jets due to the retarded way it was packaged. But its hardly impossible if you just practice for 15-20 min on a local server (which should be done anyways if you want to be good with it.). The J-10 has rudder problems as well though (you'll notice a slight drift to the left).
Taking off for me:
1. Throttle 100%
2. Once I'm moving I hit burners (you're runway is pretty short and theres that annoying fence there for some reason).
3. I usually get to 800-900 before taking off.
4. Once past 800 I pitch back on the stick, once I'm pointing up I reengage burners.
Look the J-10 is harder to get off the ground than most jets due to the retarded way it was packaged. But its hardly impossible if you just practice for 15-20 min on a local server (which should be done anyways if you want to be good with it.). The J-10 has rudder problems as well though (you'll notice a slight drift to the left).
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Alex6714
- Posts: 3900
- Joined: 2007-06-15 22:47
Taking off is not the problem, landing is. The thing just doesn´t stop. I can land the eurofighter first time and all the time after that. The J-10? I have to jump out to get that to stop. I feel like my FSX 747 is more maneuverable.
I ask, please if the J-10 can be somewhat balanced against the eurofighter in the next patch. I mean a rock that doesn´t move turns faster...
Also, I believe the aircraft in general could do with much better physics, but hey, BF2 engine. I hope all that can be done is going to be done.
I ask, please if the J-10 can be somewhat balanced against the eurofighter in the next patch. I mean a rock that doesn´t move turns faster...
Also, I believe the aircraft in general could do with much better physics, but hey, BF2 engine. I hope all that can be done is going to be done.
"Today's forecast calls for 30mm HE rain with a slight chance of hellfires"
"oh, they're fire and forget all right...they're fired then they forget where the target is"
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CAS_117
- Posts: 1600
- Joined: 2007-03-26 18:01
Yes the J-10 blows compared to the EFT (not far from reality) and I'm work(ing/ed) on it. As you know the AAM's proximity fuse, but unfortunately the radius is smaller than the distance the plane travels in 0.1 seconds or so. Thats why you see them detonate sometimes and not kill anything.Alex6714 wrote:Taking off is not the problem, landing is. The thing just doesn´t stop. I can land the eurofighter first time and all the time after that. The J-10? I have to jump out to get that to stop. I feel like my FSX 747 is more maneuverable.
I ask, please if the J-10 can be somewhat balanced against the eurofighter in the next patch. I mean a rock that doesn´t move turns faster...
Also, I believe the aircraft in general could do with much better physics, but hey, BF2 engine. I hope all that can be done is going to be done.![]()
Think the BF2 hotboxes except +/-50 away from the jet as opposed to 1 or 2 as an infantryman. AAM's were supposed to have the same accuracy to even things out, but thats not the case. Some things have been lost in translation. Try hitting a plane with a gun when its turning. Can't do it? You'll notice that your rounds are exploding but its still flying. Now shoot it when its landed. Died right away probably. When a plane is turning its hitbox is ahead and above it. When its straight, the hitbox is right in front, and while some rounds miss, a lot don't.
It gets better. Try diving with your plane. Now climb. There may be about a 200 kph difference, but notice that when you're in a dive you actually SLOW DOWN. Inversely you speed up in a climb. Why? Its because you have a set of invisible training wheels pre-built onto your plane to make it palatable for the general swaddling masses. In order for planes to be flyable, they do not accelerate due to gravity when descending. So this makes realistic physics much more complicated.
Also try flying at high altitude. You start to lose control and fly away into the sunset for eternity. This happens due to the fact that your plane is more affected by the momentum of your ascent than it is by the force of gravity pulling it down.
If you wisely chose to skip that long winded response get this: you're not flying an airplane, its closer to a flying saucer.

