Route mode

[AlphaOneSix]

the 20% authority rule only aplies when u the pilot gives input, if the pilot doesnt touch cyclic or collective the ap basically has 100% authority. (or u can say 20% of 100 = 20 authority vs 80% of 0 = 0 authority)

 

The "20%" rule means that the autopilot can only move the flight control actuators through 20% of their total range of movement. They are never able to input more than that.

[slug88]

How important is it on a mission to know what your required altitude and speed are? Maybe I think its more important than it actually is. I have only really flown one practise mission several times I made myself, for training.

 

It's extremely important. Which is one of the reasons that, in real life, pilots often sit through hours long briefings before embarking on missions. It's also one of the reasons that pilots also carry clipboards and charts with them while flying.

 

Usually, of course, you're not supplied with this information during the briefing, which is unrealistic. Therefore, you have to take the unrealistic step of looking it up in the ABRIS. It's not a fault of the sim or the helicopter, but of the (imho) inadequate briefings that are supplied for most missions.

[Frederf]

Agreed, the typical combat pilot will spend 10 hours briefing a 3 hour flight. Every contingency down to where you are allowed to drop your spent fuel tanks or ordinance in case of jettison is covered.

 

Also in real life, when working with other forces, timing is everything. Real life doesn't work like Black Shark with its convenient triggers so you're never late for the battle.

 

I have always insisted that the pre-flight environment is half of flying and any sim without a decent pre-flight environment is mediocre at best.

[BTTW-DratsaB]

That's what I figured, even more reason to be surprised that not one of those indicators, Hud, ADI, HSI can show you what alt and speed to fly at, as assigned for the route. Oh well, that's just the way it is I guess.

 

The description of the ADI in the manual really makes its sound like that is what the indicators at the side are supposed to do :/

 

9. Deviation from assigned altitude. This vertical scale and yellow caret on the right side of the ADI indicates the aircraft‟s current altitude in relation to the assigned altitude for the current leg of the route. If the aircraft is too high or too low, the caret will be below or above the center mark. The caret being above the center point would indicate that the aircraft was below the assigned route leg altitude.

 

One other thing I have noticed about the ADI (seems the same in the training and producers notes) is that one of the "Error Flags" is always shown.->

 

2. Assigned pitch and bank steering not available flag. If no steering information is available, this red flag will be visible in the top left corner of the ADI.

 

how do I make this turn off and is there any chance that this might be causing a problem?

[hyperfighter]

The "20%" rule means that the autopilot can only move the flight control actuators through 20% of their total range of movement. They are never able to input more than that.

 

ye sure, so the 80% rule then obviously means the pilot can only move the flight control actuators through 80% of their total range of movement.

 

my game must be bugged because i have no probs giving 100% input...

 

u dont get my point, ofcourse the ap wont give max inputs because it would make the helo crash for sure! especially if u need to turn like 180degrees

i think its like this comp is giving 20% input and u give 20 % input in opposite direction, i bet the helo will not fly straight but will go to towards the input of the pilot, because the pilot has 80% authority...at least thats how i thought it was, this might be wrong, nevertheless if u dont give input the ap has al the control and so will fly exactly to the wp indicated, not like 20% in that general direction, so basically the ap has 100% authority then, the ap decides a 100% where you will end up

let me ask u this how much is 80% of nothing and how much is 20% of 100 %input by ap???

correct me if i am wrong but 80% of nothing is nothing, .0000001% of a very little bit is still more right?

 

in short the ap gives 100% input but only has 20% authority so yes thats 20% max input

if u give 20% input (80 percent of 20 is 16, --> ap will win)

Edited March 18, 2009 by hyperfighter

[AlphaOneSix]

I think you're misunderstanding the 20% thing. If you look at an actual flight control actuator, it has a piston that moves by hydraulic pressure and acts on the rotor system for control. Let's say that on the Ka-50, the pistons on those actuators have a travel of 10 inches (I don't know the actual number). The autopilot can only move that piston a maximum of 2 inches (20% of 10 inches). The pilot can move the piston through 100% of it's travel, all 10 inches.

 

I understand what you mean by the autopilot having 100% control of the aircraft, because the pilot doesn't have to touch the controls at all, and the autopilot will faithfully follow your flightplan and can essentially fly forever without any input from the pilot. But it does so by never moving the pistons of the actuators more than 2 inches (assuming my guess of 10 inches is correct, which it almost certainly is not).

 

If the pilot moves the controls while the autopilot also tries to maintain a course, the autopilot will input an opposite control until it reaches its 2 inch limit (the flight control actuator's piston will remain stationary). If the pilot keeps moving the controls beyond that 2 inch limit, the pilot's control inputs will start getting through to the rotor system (the AP will stop at its 2 inch limit but the pilot continues giving input, so the piston starts moving).

[Frederf]

That's what I figured, even more reason to be surprised that not one of those indicators, Hud, ADI, HSI can show you what alt and speed to fly at, as assigned for the route. Oh well, that's just the way it is I guess.

 

The description of the ADI in the manual really makes its sound like that is what the indicators at the side are supposed to do :/

 

One other thing I have noticed about the ADI (seems the same in the training and producers notes) is that one of the "Error Flags" is always shown.->

 

how do I make this turn off and is there any chance that this might be causing a problem?

 

The ADI does show command steering for left/right, alt, and speed when put in the correct mode. However the "assigned" values are not what you think. When you are going 173 km/h and you hit trim then the "assigned" speed becomes 173 km/h. All value assignments for speed and altitude are done by the pilot during flight. Command steering cues can be shown to fly DH or DT to PVI waypoints though, or simply to hold a heading.

 

 

---

 

 

ye sure, so the 80% rule then obviously means the pilot can only move the flight control actuators through 80% of their total range of movement.

 

my game must be bugged because i have no probs giving 100% input...

 

u dont get my point, ofcourse the ap wont give max inputs because it would make the helo crash for sure! especially if u need to turn like 180degrees

i think its like this comp is giving 20% input and u give 20 % input in opposite direction, i bet the helo will not fly straight but will go to towards the input of the pilot, because the pilot has 80% authority...at least thats how i thought it was, this might be wrong, nevertheless if u dont give input the ap has al the control and so will fly exactly to the wp indicated, not like 20% in that general direction, so basically the ap has 100% authority then, the ap decides a 100% where you will end up

let me ask u this how much is 80% of nothing and how much is 20% of 100 %input by ap???

correct me if i am wrong but 80% of nothing is nothing, .0000001% of a very little bit is still more right?

 

in short the ap gives 100% input but only has 20% authority so yes thats 20% max input

if u give 20% input (80 percent of 20 is 16, --> ap will win)

 

*facepalm* Hyperfighter, let me explain how this AP 20% works. The command chain goes as follows Cyclic--->Autopilot--->Flight Controls. The AP is between the cyclic and the resulting flight control movement and can add its own fudge factor to serve its use.

 

Let's take a simple example of cyclic bank input. Let's say that full left bank on the stick is -1.0 and full right bank on the stick is +1.0. The pilot always has 100% authority over the controls meaning he can command anywhere between -1.0 and +1.0 to the Flight Controls.

 

Now let's pretend that the cyclic is centered (0.0) and the AP is on. The AP's 20% of the entire movement range authority can take the 0.0 value from the stick and fudge it anywhere between -0.2 to +0.2 before passing along this input to the Flight Control computer. The physical cyclic stick is still centered at the 0.0 value but the Flight Controls are behaving as if the stick is were the AP input says it is.

 

If the cyclic stick is fully left (-1.0) then the AP can only adjust the stick input from -1.2 to -0.8, but since there's no such thing as -1.2 the AP range is actually -1.0 to -0.8.

 

Now you may think if the pilot pushes the cyclic stick all the way to the right at +1.0 that the AP could adjust the input all the way down to +0.8 if it wanted to and the pilot would be prevented from full 100% authority. However, there's a mechanism that detects when the pilot pushes the cyclic and disengages the AP's authority from 20% to 0%.

 

This is why AP 20% authority is sometimes not powerful enough to put all the input that is needed to get the AP's job done. Example: The rudder pedals are trimmed at +0.3 and the AP needs to make the rudder input be -0.1 to prevent the helicopter spinning around and around when at a hover. However the AP only has the authority to adjust the rudder input 20% (+0.5 to +0.1) so the AP's authority is insufficient to do the job the AP wanted to do.

[elproducto]

Sorry to necro this thread, but I didn't want to start a new one.

 

Last night I was trying Route Mode for the first time on Death Valley, and it seemed to fly me quite high. When I approached the waypoint from which I was to commence my attack, I tried to make a descent. Apparantly I did so to fast, because something happened and I just continued to descend until I crashed. None of my collective inputs mattered, although my rotors were still spinning. I'm assuming I descended too fast.

 

I guess my question is twofold:

 

1. How is flight elevation handled in route mode?

2. How do you make a controlled descent. Obviously if I pitch the aircraft forward I gain speed.

[flanker0ne]

In Route mode, the elevation still controlled with the Collective Brake [F], assuming you have the AP Altitude Hold On. For little altitude change you can hold the Collective Brake and release it at the new altitude. For large change in altitude is better deactivate the AP Altitude Hold

 

A controlled descend, is a "Flat" descend where you hold a horizontal attitude while decrease collective and maybe pull down the Throttles.

For the Emergency descend, you have a Dive attitude and you have to decrease the Governors with the switch "Nominal RPM" for avoid rotor Overspeed.

[elproducto]

Awesome, that makes total sense. Thanks!

 

I didn't know about the collective break, perhaps I should be mapping that to my HOTAS.

[AlphaOneSix]

The collective brake is basically just a trimmer for the collective. If you do not have altitude mode engaged on the autopilot, then the brake (F) has no function. When you do have altitude mode engaged, holding the brake will allow you to change altitude without the AP fighting you, and when you release the brake, the AP will try to hold the altitude at the point of release.

 

In practice, with the altitude mode engaged, you would press and hold the brake, adjust the collective to climb or descend to your new desired altitude, stabilize at the new alititude, then release the brake. If you don't mind fighting the AP a little bit, then you can just press and release the brake once you've stabilized at your new altitude.

 

Personally, I don't think it deserves its own HOTAS button, but hey if you have the buttons and nothing better to assign to them... If you are done with your need to hold altitude, just turn off the altitude mode of the autopilot.