Autopilot VS mode.

[colmbo]

Best climb speed doesn't change much...

Best rate speed decreases as you climb.  For a Cessna 206 (an example I'm familiar with) SL Best rate is 100mph IAS....it decreases as you climb, by 10,000' you're down to 83mph IAS.

[FLS]

Isn't that because thrust is decreasing too?

I don't think auto speed will always give you the best possible climb rate but it's a good approximation and I think Krusty is approximating his explanation for MachFly.

Krusty's main point seems to be that setting a fixed climb rate will not do what MachFly thinks it will do.

[MachFly]

Machfly in your first example the faster aircraft would zoom up under you and shoot you down. It wouldn't matter that you can out climb them because they don't have to ram you.

If you look at a climb rate chart you'll see that the climb rate decreases with altitude for a given power  output. This means that setting a given max climb rate will always cause you to stall as the air density decreases which is what Krusty pointed out to you.

Flying slower than your best climb speed doesn't let you climb faster because the higher AOA has more induced drag. Flying slower than your best climb speed gives you a lower climb rate.

The auto speed defaults to best climb speed which gives you your max climb rate.

If both aircraft are at equal energy at the bigging this maneuver always works (I fly a spit14, climbs at 5000ft/min with 50% fuel). I would never do this if the aircraft behind me have more energy.

The climb rate decreases with altitude for all aircraft, not just my, so the maneuver still works. Your right it will cause you to stall if you keep the same AoA for a long time, if you do that for about two thousand feet it works fine, than you usually have at least 1K separation from the enemy aircraft.

Flying slower than my best climb speed does indeed decrease my climb rate, however most of the time your this maneuver puts you in such position that you that enemy aircraft can not pull his nose up to you. I use this when I don't have time to accelerate to my best climb speed.

I don't think the auto speed gives you the best climb rate because it is 160 for all fighters, the number has to be different. (I might be wrong about this one)

[MachFly]

Isn't that because thrust is decreasing too?

I don't think auto speed will always give you the best possible climb rate but it's a good approximation and I think Krusty is approximating his explanation for MachFly.

Krusty's main point seems to be that setting a fixed climb rate will not do what MachFly thinks it will do.

It seems that Krusty does not understand my point, that is all.

[MachFly]

Assuming the OP is referring to rate of climb, You can set the rate of climb by hitting shift-X while the plane is at the angle of attack you want.

Isn't that essentially what he's asking for?

You want a ROC of 1000 ft/min?  Pull back on the stick until you get 1000 ft/min ROC, then hit shift-x. You should be set.

Shift-x is what you are talking about and you already have it. If your airplane is incapable of holding that angle it will fall.

Now if you also want a dot command like ".rate 3800" just say so. Problem is you may not be able to sustain that rate which is what Krusty is saying.

You are absolutely right, shift-x does exactly what I want. (I did not normally use it therefore I forgot that it even existed and how it works)

Now all we need it to be able to set the ft/min climb for it.

[gyrene81]

I don't think the auto speed gives you the best climb rate because it is 160 for all fighters, the number has to be different.

no it's not...default climb speed is different, for all aircraft...not sure where you got the idea that it was the same across the board.

Now all we need it to be able to set the ft/min climb for it.

you can, climb or descend...i use the stick to do it...just checked and no dot command

[MachFly]

no it's not...default climb speed is different, for all aircraft...not sure where you got the idea that it was the same across the board.

you can, climb or descend...i use the stick to do it...just checked and no dot command

So after take off if I press alt x the airplane would climb at it's Vy (or Vx)?


Right can use climb or descend on autopilot by setting it up with the stick, I'm saying I would like to have to dot command for the climb rate. Just like we have it right now for the autopilot at speed mode.

[gyrene81]

i believe it's Vy optimal climb rate...fairly certain Vx is optimal angle

[SgtPappy]

Well you could always set an auto speed and then go into constant-speed mode. i.e. Using .speed 200 and hitting alt + x, allowing the plane to maintain the speed. Sometimes you don't even want best climb speed, because that speed could be too slow if followed by cons.

In the F4U-4 for example, I can reach high speeds at any alt quickly (just like the Spitfire XIV), and so what I like to do is use this speed to climb. What tends to work for me is accelerating to say, 300+ mph and pull up until I'm climbing JUST over 4000 fpm. You can either check the E6B or just go to zero G's just after you hit 4000 fpm on the VSI. Since your plane is so fast (and can climb well), then you'll be outrunning them more than you are outclimbing them. But since you're technically climbing at a shallow angle, you won't be losing speed quickly at all (in the Spit14 and F4U-4 anyway) and you're still gaining altitude at 4000 fpm.

Any plane that can't easily outclimb you will probably not be able to follow. You could even add a wide turn to the climb by simply banking in one direction without pulling more than 1 G (i.e. using gravity to pull you through the turn). Then the enemy will be tempted to turn tighter, climb and run after you, losing much speed in the process, while you're barely decelerating.

[MachFly]

Well you could always set an auto speed and then go into constant-speed mode. i.e. Using .speed 200 and hitting alt + x, allowing the plane to maintain the speed. Sometimes you don't even want best climb speed, because that speed could be too slow if followed by cons.

In the F4U-4 for example, I can reach high speeds at any alt quickly (just like the Spitfire XIV), and so what I like to do is use this speed to climb. What tends to work for me is accelerating to say, 300+ mph and pull up until I'm climbing JUST over 4000 fpm. You can either check the E6B or just go to zero G's just after you hit 4000 fpm on the VSI. Since your plane is so fast (and can climb well), then you'll be outrunning them more than you are outclimbing them. But since you're technically climbing at a shallow angle, you won't be losing speed quickly at all (in the Spit14 and F4U-4 anyway) and you're still gaining altitude at 4000 fpm.

Any plane that can't easily outclimb you will probably not be able to follow. You could even add a wide turn to the climb by simply banking in one direction without pulling more than 1 G (i.e. using gravity to pull you through the turn). Then the enemy will be tempted to turn tighter, climb and run after you, losing much speed in the process, while you're barely decelerating.

Yeah that works.
I usually just do a slow straight climb and then drive back to kill off the enemy. If I run straight both of us get more energy, if I climb I can dive back down while the other guy is still slow trying to climb up to me. Since spit14 can climb at 5000ft/min it's a very easy thing to do, and makes 1 v 2+ flights a lot easier.

You described how I can use alt x and than when the pitch is right switch to shift x. I think it's a long proses and it's a lot faster to just do that with a stick. But if we could have previously have climb rate one button could put you into a climb.

[FLS]

It seems that Krusty does not understand my point, that is all.

I think you have that backwards but it's not worth arguing about.

Start with default auto speed for best climb rate then tweak it by changing the speed slightly and see if your climb rate improves. 

[kvuo75]

I don't think the auto speed gives you the best climb rate because it is 160 for all fighters, the number has to be different. (I might be wrong about this one)

it is different. examples:

a6m's = 146
109e4 = 150
109f4 = 155
109g2 = 160
c205 = 164
f4f = 150
190a5 = 159
190d9 = 169
i-16 = 129
hurricanes = 140
ki84 = 163
mossies = 170
p51's = 174
temp/typh = 185
spit 5 = 160
spit 14 = 175
p40's = 144
p39's = 162


why do i have these #'s handy? i was bored one day and tested every plane     

[gyrene81]

i just reread machfy's posts...and realized  ...you want the plane to do the work for you in a fight so you don't have to watch your instruments...lazy. 

[hitech]

What your asking for is not possible.

You are asking for sea level best climb rate at all altitudes. Obviously since climb rate decrease with Altitude. This can not happen.

Best climb rate is achieved at the speed in which the plane has the most EXCESS thrust horse power. Thrust HP differs from break HP. in that it includes prop inefficiency.

HP definition is the ability to lift 550 lb 1 ft in 1 sec. I.E. Horse power IS climb rate for any given weight. Hence why best climb is achieved at the greatest EXCESS HP.

Excess HP definition is simply Thrust HP - Drag HP.

Drag HP Decrease from stall speed to  about 140 % of stall speed then starts increasing. I.E. stall speed of 100 best climb will be around 140. 40% Is just a good rule of thumb.

..............

Definition Vx Vy.

Vy Velocity at which you achieve the best climb rate.

Vx is the Velocity at which the greatest climb angle is achieved I.E. most climb with least forward motion. It is used when a high structure is near the end of the runway.

HiTech

[MachFly]

What your asking for is not possible.

You are asking for sea level best climb rate at all altitudes. Obviously since climb rate decrease with Altitude. This can not happen.

Best climb rate is achieved at the speed in which the plane has the most EXCESS thrust horse power. Thrust HP differs from break HP. in that it includes prop inefficiency.

HP definition is the ability to lift 550 lb 1 ft in 1 sec. I.E. Horse power IS climb rate for any given weight. Hence why best climb is achieved at the greatest EXCESS HP.

Excess HP definition is simply Thrust HP - Drag HP.

Drag HP Decrease from stall speed to  about 140 % of stall speed then starts increasing. I.E. stall speed of 100 best climb will be around 140. 40% Is just a good rule of thumb.

..............

Definition Vx Vy.

Vy Velocity at which you achieve the best climb rate.

Vx is the Velocity at which the greatest climb angle is achieved I.E. most climb with least forward motion. It is used when a high structure is near the end of the runway.

HiTech

I am actually asking for the ability to be able to set my climb rate for autopilot (like a dot command). I understand as you increase in altitude you will stall out, that is exactly why the procedures for all autopilots state that you should not keep your autopilot in VS mode for long climbs.

If I'm in a cruse and I want to enter a slow climb I'd be able to just type climb .1000 and start a 1000ft/min accent. Then it is my responsibility to turn off the autopilot at the right time (or before that).