Trim Type?

[MrReynolds]

Hi all.

Flew the Blackshark in V1.0 days and loved the way the trim worked.  Fly the stick, hit trim and it would.....trim.

Having played around with the Little Bird and using it's push pull hat trimmer I must say I hate that way.

 

So.  How will the trim work in this beast?  Any ideas?

 

TIA.

[Raptor9]

It's a standard magnetic brake force trim system like the Huey.  No fine-tune servo trim controls like the Gazelle.  However, unlike the Huey, it has a flight computer to keep the aircraft extremely stable like the Ka-50.

 

Push the force trim interrupt to release the mag brake, let go of the force trim interrupt to engage the mag brake.  Fortunately, there is also a mag brake on the pedals, so you can force trim those as well.

Edited April 17, 2021 by Raptor9

[MrReynolds]

Just seen this, thanks for the reply

I got the Gazelle in the sale as my "trainer" for the 64......

Haven't had much need for trim to be honest, although I do prefer the mag trim out of the pair.

Thanks again.

[Focha]

In the AS365 we had the two systems. The Force Trim button and the Beep Trim coolie. Both worked, but I liked the Force Trim better for change large amplitudes and Beep Trim to change small corrections on trim.

 

The Ka-50 trim works like a charm. Better yet if the still is FFB.

 

As for the Gazelle, I don't really like nothing on that helicopter... at least on control/reaction behaviour.

Edited April 24, 2021 by Focha

[MrReynolds]

I've followed guides to reduce stick movement and I'm beginning to hop around like I used to in the Ka-50  10+ years ago!

Can't turn on a dime yet, but getting there

Edited April 27, 2021 by MrReynolds

[M1Combat]

"Fly the stick, hit trim and it would.....trim."

 

In general...   In the shark you want to Press trim, fly the aircraft to a new attitude you'd like to have trim hold for you, then release trim.  the details of that get a little murky depending on your controller (FFB??  No centering Springs??) and which settings you're using in the options page.  But you want to press, fly, release.

Edited May 6, 2021 by M1Combat

[Air Joker]

Sorry, but I´m not very familiar with helicopter-triming-systems. My only experience is the DCS-Huey, that I downloaded last mounth.

I'm already looking forward to the Apache, but I can´t imagine how the Apache will fulfill his orders with a "simple" trim-system like the Huey. I guess, there must be a better one.

 

Simply asked, is there a "button", that keeps the Apache in a stable hovering, in a stable height, without any rotation at all weather conditions, so that the crew can concentrate on their tasks?

If not, it will be hard for the players to hover stable, aim and fire weapons...especially in a complicated simulator like DCS...I´m sure, I can´t do that all at same time?!

Edited May 11, 2021 by Air Joker

[3WA]

On 4/17/2021 at 12:07 PM, Raptor9 said:

It's a standard magnetic brake force trim system like the Huey.  No fine-tune servo trim controls like the Gazelle.  However, unlike the Huey, it has a flight computer to keep the aircraft extremely stable like the Ka-50.

 

Push the force trim interrupt to release the mag brake, let go of the force trim interrupt to engage the mag brake.  Fortunately, there is also a mag brake on the pedals, so you can force trim those as well.

 

 

Well, this sounds a lot like the Shark, except that it actually resets the center of the stick as well.  I don't fly the Huey, so I don't know it's system.

 

49 minutes ago, Air Joker said:

Sorry, but I´m not very familiar with helicopter-triming-systems. My only experience is the DCS-Huey, that I downloaded last mounth.

I'm already looking forward to the Apache, but I can´t imagine how the Apache will fulfill his orders with a "simple" trim-system like the Huey. I guess, there must be a better one.

 

Simply asked, is there a "button", that keeps the Apache in a stable hovering, in a stable height, without any rotation at all weather conditions, so that the crew can concentrate on their tasks?

If not, it will be hard for the players to hover stable, aim and fire weapons...especially in a complicated simulator like DCS...I´m sure, I can´t do that all at same time?!

 

 

As above, it sounds more like the Shark.  The Shark has the auto hover and other stuff because your a single pilot.  In the Apache, you have a pilot and a gunner, which should make things a lot easier.  I can pilot it, and let the gunner worry about firing Hellfires and the gun.

[Raptor9]

Chuck's Ka-50 Guide explains the whole "virtual" force trimming system in DCS on page 95.  It's the same logic that is used throughout all the helos in DCS to simulate "force trim" or "trimmers".  The DCS logic of handling differences between "virtual controls" in-game that can be mag-braked into place, while linked to spring-loaded-to-center physical controls in the player's hands, can be tough to wrap your head around. (This is assuming the player isn't using a force-feedback stick that can hold the physical stick in a set position)

 

Additionally, real-world helicopters don't have a "Reset Trim" command in them to "re-center" the force trim mag brake.  That is only a thing in DCS to compensate for the virtual controls vs physical controls thing, and to help the player re-sync the two if necessary.  Some helicopters do have an airplane-style trim control, that applies pitch/roll input on the flight control servos independent of cyclic movement; but the "Reset Trim" command that exists in the Ka-50, UH-1 or Mi-8 is only a game-ism to help with the "force trim" simulation in DCS World.
__________________________________

 

The AH-64 and the Ka-50 have a lot of similar functionality in their autopilot functions, it's just the logic of selecting them are vastly different.  Another difference between the AH-64 and the Ka-50 is that the Shark has an actual autopilot system with sub-modes selected via switches, capable of navigating a route or turning toward a target/nav point; whereas the AH-64 only has hold modes similar to the A-10C or F-16, but the sub-modes are automatically determined by the Apache based on flight conditions that exist when the hold modes are selected.

Ka-50: requires pilot action to disable autopilot functionality (by turning Flight Director on, which doesn't turn off any activated autopilot functions, like auto-hover, it just blocks it from affecting the flight controls)

AH-64: requires pilot action to enable hold mode functionality (which sub-modes are entered are determined by the aircraft automatically based on flight condition)

Edited May 11, 2021 by Raptor9

[Air Joker]

Thanks for the answers

 

If I get it right, the Apache realizes, that I´m hovering, so I can take my hands away from the pilot stick and eat something for lunch, while the helicopter continues to hover at the same place until I've finished...something like that.

 

I´m fighting every second with the UH-1H to keep it in place or on course...that could end with the computer-controlled Apache.

But it remains to be seen whether this is pleasant or whether it gets a little bit boring over time.

[3WA]

Not sure about the Apache, but the Ka-50 does have an auto hover.  However, you have to get it in a near perfect hover, and then hit the button.  Otherwise, it doesn't work.

 

And in strong winds, it hardly ever works well.

[Raptor9]

Like the Ka-50, the 64 needs to be in a relatively trimmed hover for the hold mode to keep it there. Otherwise, like the Ka-50, the servos may run out of authority and it may drift.

[MrReynolds]

Thanks all.  I'm now pretty much back up to speed with the gazelle.  Bring on the big bird!

[MAXsenna]

Not sure about the Apache, but the Ka-50 does have an auto hover.  However, you have to get it in a near perfect hover, and then hit the button.  Otherwise, it doesn't work.
 
And in strong winds, it hardly ever works well.

Use the velocity bar!

Sent from my MAR-LX1A using Tapatalk

"Fly the stick, hit trim and it would.....trim."
 
In general...   In the shark you want to Press trim, fly the aircraft to a new attitude you'd like to have trim hold for you, then release trim.  the details of that get a little murky depending on your controller (FFB??  No centering Springs??) and which settings you're using in the options page.  But you want to press, fly, release.

FFB is perfect for helicopters in DCS, well three of them at least. The Gazelle is actually harder to fly for me with FFB.
Anyway, you press trim, your stick gets "limp", release trim, and the stick stays there.
It's all very natural, you know where your stick is all the time hovers are "easy", etc.
Cheers!

Sent from my MAR-LX1A using Tapatalk

[Reticuli]

The vast majority of users (I'd say very close to 100%) will have standard spring-loaded centering or pressure sticks, and only a teeny tiny number will have either 1) professional helo-sim long-pole cyclics with built-in damping or a physical mechanical trimmer or 2) a FFB stick of which very few models are even manufactured anymore and many that previously were lacked reliability.  The primary control law used in helos with a normal joystick or pressure stick is simple: rate-command / attitude-hold (a.k.a. RC/AH), and maybe with some optional IAS or velocity command or wings-leveling modes for various other situations.  Any other weird hybrid method such as bouncing from additive manual force trim designation summing with the current stick input until you recenter or ignoring the stick input after manual force trimmer until you recenter is clunky and ill-advised.  How the real Apache does it is largely moot other than possibly as rarified settings options for those with pro long-pole (damped or mechanically-trimmed) cyclics or a FFB stick, because, again, most users will not have the required hardware to properly utilize such a flight control scheme, anyway, and the combined result they will experience will be even further from reality or even reasonable practicality.  This is why Janes Longbow Anthology scored a slam dunk with their joystick scheme after they threw out the other method in early testing... not that I'm advocating ED only do RC/AH.  They should have three modes: 1) default RC/AH for joy & pressure sticks, 2) a manual force trimmer mode for either FFB stick users or masochists who enjoy awkwardly manual force trimming helos with a centering joystick, and 3) a non-RC/AH and non-force-trimming mode for users of expensive pro long pole cyclics that have their own built-in deflection hold or just people who chose to remove their spring from their joystick and like to keep their hand on it all the time (good luck with that).  Before you disregard this you need to ask yourself, what's more realistic, forcing (no pun intended) an antiquated manual trim system on users with completely the wrong control hardware, or utilizing a methodology that literally every helicopter (experimental or otherwise) that has used a joystick or pressure stick actually used?

Edited May 21, 2021 by Reticuli

[Reticuli]

On 5/10/2021 at 8:07 PM, Air Joker said:

Sorry, but I´m not very familiar with helicopter-triming-systems. My only experience is the DCS-Huey, that I downloaded last mounth.

I'm already looking forward to the Apache, but I can´t imagine how the Apache will fulfill his orders with a "simple" trim-system like the Huey. I guess, there must be a better one.

 

Simply asked, is there a "button", that keeps the Apache in a stable hovering, in a stable height, without any rotation at all weather conditions, so that the crew can concentrate on their tasks?

If not, it will be hard for the players to hover stable, aim and fire weapons...especially in a complicated simulator like DCS...I´m sure, I can´t do that all at same time?!

 

Apaches have hover hold, altitude hold, and separate heading hold modes that can all be enabled.  The heading hold mode is usually left on, and you push past a threshold with the pedals to induce a yaw when it's engaged.  You do not designate a heading with some trimmer or by toggling the SAS channel, and the channel yaw authority is more than sufficient for the task to hold a heading when your foot is off the pedal, unlike the goofy and anemic one in the DCS implementation of the Ka-50.  Auto turn coordination (yaw when you bank) also begins to feed-in above a certain forward IAS.

Edited May 21, 2021 by Reticuli

[Raptor9]

On 5/20/2021 at 11:05 PM, Reticuli said:

Apaches have hover hold, altitude hold, and separate heading hold modes that can all be enabled.  The heading hold mode is usually left on, and you push past a threshold with the pedals to induce a yaw when it's engaged.  You do not designate a heading with some trimmer or by toggling the SAS channel, and the channel yaw authority is more than sufficient for the task to hold a heading when your foot is off the pedal, unlike the goofy and anemic one in the DCS implementation of the Ka-50.  Auto turn coordination (yaw when you bank) also begins to feed-in above a certain forward IAS.

 

Well first off, the AH-64 heading hold cannot be toggled off, however it does have contextual conditions that determine what sub-mode it operates in, and how much input it uses to affect the directional servo.  Second, you do designate a heading you want the flight computer to hold by releasing the force trim interrupt ("trimmer") when you get the aircraft established on said heading; in fact it even puts a chevron on the heading tape in certain symbology modes when you do so as a reference, just like the Ka-50.  Third, the AH-64 heading hold (like the Ka-50), will only hold a heading if the aircraft is trimmed properly to do so.  These hold modes only have a limited authority in them, so while they'll hold the aircraft in a coordinated flight profile, they won't if flying an uncoordinated profile that exceeds their control authority.

I know very few pilots that ever take their feet off the pedals, even when in stable, coordinated flight.

[Reticuli]

16 hours ago, Raptor9 said:

 

in fact it even puts a chevron on the heading tape in certain symbology modes when you do so as a reference
 

As far as I've ever read, only the bob-up mode shows that and it's based on when you enter that mode with the symbology switch, rather than when you released the trimmer.  I've never seen information there's release trim symbology for the heading that's being held on the Apaches, rather the heading hold otherwise seemed intuitively based on when you stop the yaw rotation at lower speeds and it 'captures' the new heading.  I thought at low speeds the pilot flying pushes past a threshold with the pedals to override that captured heading and induce a yaw.  Stop the yaw, and again it's back to capturing this new heading.  Maybe I'm getting the Apache manuals mixed up with the ADOCS, LHX, and Comanche whitepapers' flight laws.  You're telling me at low speeds if you apply the pedals on the Apache to induce a yaw past that threshold from the current heading it's holding, rotate the aircraft 90 degrees, halt the yaw rate with the pedals, and don't apply additional anti-torque it's going to try and rotate back to the original heading 90 degrees to the other direction because you didn't manually-designate a new SAS heading?

I'm not exactly sure what you mean by holding a coordinated profile in the context you're saying.  If it's holding a heading, the aircraft is not coordinating with yaw based on any other input axis.  Above a certain airspeed the auto turn coordination ought to mix-in yaw to center the ball when you apply roll instead of holding a heading anymore.  Maybe you mean this in some other context, like just attitude & heading hold authority %?  But come on, man, the DCS Blackshark FD mode heading hold authority is WEAK.

The Apache manuals do talk about the pedals in relation to the force trim state, though, so I'm wondering if indeed it's either ignoring what the pedals are doing within a certain distance from when you last released the trimmer or if it's doing something with the pedal's tension to prevent movement... and then doing its own SAS rate damping or attitude/heading hold with this lack of new recognized pedal input.

Edited June 17, 2021 by Reticuli

[Raptor9]

2 hours ago, Reticuli said:

As far as I've ever read, only the bob-up mode shows that and it's based on when you enter that mode with the symbology switch, rather than when you released the trimmer.

 

Correct.  What I was trying to say was that you can in fact assign a heading value to the Heading Hold by releasing the force trim just like the Ka-50, the only difference being that the Apache requires an additional button press to update the Command Heading to match.  This is what happens when I type late at night and don't proof-read my messages.

 

You get the aircraft established into a stable hover, you release the force-trim interrupt, which assigns the heading hold to that current heading value; and then when you switch from Hover to Bob-Up, it assigns the Command Heading symbol to that current heading as well.  Like the Ka-50, when you release the force trim after getting established on a new heading, the Apache will set that current heading value as what it will try to hold.  Unlike the Ka-50, however, the command heading will only update when you re-cycle the Bob-Up mode.

 

2 hours ago, Reticuli said:

rather the heading hold otherwise seemed intuitively based on when you stop the yaw rotation at lower speeds and it 'captures' the new heading.  I thought at low speeds the pilot flying pushes past a threshold with the pedals to override that captured heading and induce a yaw.  Stop the yaw, and again it's back to capturing this new heading.

 

Correct, until you reach a certain breakout value, in which case it will disengage until conditions are met to re-establish a new heading hold value.  However, this is all contingent on the force trim not being pressed.  Like the Ka-50, any time you press the force trim interrupt (aka trimmer), all hold functionality ceases until the force trim interrupt is no longer pressed.

 

2 hours ago, Reticuli said:

You're telling me at low speeds if you apply the pedals on the Apache to induce a yaw past that threshold from the current heading it's holding, rotate the aircraft 90 degrees, halt the yaw rate with the pedals, and don't apply additional anti-torque it's going to try and rotate back to the original heading 90 degrees to the other direction because you didn't manually-designate a new SAS heading?

 

No, I didn't say anything like that at all, nor is that the case in the Apache.

 

2 hours ago, Reticuli said:

I'm not exactly sure what you mean by holding a coordinated profile in the context you're saying.  If it's holding a heading, the aircraft is not coordinating with yaw based on any other input axis.  Above a certain airspeed the auto turn coordination ought to mix-in yaw to center the ball when you apply roll instead of holding a heading anymore.  Maybe you mean this in some other context, like just attitude & heading hold authority %?  But come on, man, the DCS Blackshark FD mode heading hold authority is WEAK.

 

By "coordinated flight" I mean the aircraft is flying with the turn/bank "ball" indicator centered (not in a "skid" or a "slip") and the aircraft is properly force-trimmed into a stable condition.  If the aircraft is flying somewhat sideways (and not because of a cross-wind) and the directional (yaw) servo is up against the edge of it's SAS authority (also known as "saturated") trying to hold that heading, it won't (or at least not for very long).

 

The distinction I was trying to make in regards to the Apache is that the SAS authority in each of the flight control servos are meant to help keep the aircraft as stable as possible for the purposes of a stable firing platform, not to automate certain piloting tasks like in the single-seat Ka-50, nor compensate for bad piloting techniques.  When you said:

 

On 5/20/2021 at 11:05 PM, Reticuli said:

the channel yaw authority is more than sufficient for the task to hold a heading when your foot is off the pedal

 

I was intending to make a clarification that the Apache SAS channels are not able to compensate for anything beyond very slight "uncoordinated" flight or "uncompensated" flight.  An example would be that you increase the collective to initiate a climb over terrain without also applying left pedal to compensate for the increase in torque caused by the collective increase.  In this case the heading hold will run out of authority quickly and you will need to adjust the pedals to compensate, and this is why pilots don't fly with their feet off the pedals, at least not in the Apache.  You make an input with one control, you need to adjust the other controls to compensate.
 

2 hours ago, Reticuli said:

the DCS Blackshark FD mode heading hold authority is WEAK.

 

No, it's non-existent.  When you engage the Flight Director in the Ka-50, you lose any automated or hold functionality in all axes (including altitude hold), but retain the SAS functionality of each channel.  You can still enable any flight computer function, like Hover mode, but the flight computer won't have the authority to affect any flight control servos while FD is turned on.  So you will get visual indications of these modes turning on in the HUD and such, but with the FD on it is the task of the pilot to control the aircraft in every axis.

Edited June 17, 2021 by Raptor9

[DaemonPhobos]

To keep it simple, heading hold is automatically engaged when you press the Force trim release switch to left position (attitude hold) mode and these conditions are given;

 

Pedals displaced less than 0.10 inches from trim position. 
Yaw rate is less than 3°/second. 
Roll cyclic displaced less than 0.25 inches from trim position. 
Aircraft roll is <± 3° from level.

 

The aircraft automatically get into the heading hold if these values are met.

The flight controls breakout values (when the aircraft breaks from heading hold mode) are.

 

Pitch and Roll cyclic displacement less than 0.25 inches
Collective displacement less than 0.50 in. 
Pedal displacement depends on the Attitude Hold submode as follows: 
Position hold less than 0.10 in. 
Velocity hold less than 0.20 in. 
Attitude hold less than 0.30 in

 

Not copy pasted, manually wrote all that and it was a pain.

 

 

 

 

 

 

 

[Raptor9]

8 minutes ago, DaemonPhobos said:

heading hold is automatically engaged when you press the Force trim release switch to left position (attitude hold) mode and these conditions are given;

 

Not quite accurate. Heading hold is always enabled, even without attitude hold engaged.  There are conditions on whether it is applied or not. But if I were to pick the aircraft up to a hover with no hold modes engaged, and get it nice and stable/trimmed out, when I let go of the force trim interrupt it will hold my heading unless some other factor causes the yaw servo to exceed its SAS authority. (Such as a large gust of wind acting on the tail)

[DaemonPhobos]

But when the attitude hold mode is off its only limited to below 40 knots to be active, right?

[Raptor9]

16 minutes ago, DaemonPhobos said:

But when the attitude hold mode is off its only limited to below 40 knots to be active, right?

 

The Heading Hold logic is always active independent of whether Attitude Hold is engaged. It's logic is modified somewhat if you are in one of the Attitude Hold submodes, but you can fly around all day exploiting Heading Hold functions and never touch the Attitude Hold toggle.

 

But again, it's not an all or nothing on/off logic, it's behavior is designed to be contextual based on conditions.

Edited June 17, 2021 by Raptor9

[Reticuli]

I'm assuming now that the Apache pedals do not center but that they have at least a little bit of tension in them so they aren't going to flop around on their own.  Correct?

 

DCS Blackshark's oddly-named 'Flight Director' mode with all the SAS channels on seems to have rate-damping to slow the rotations, but they're very, very weak... like unbelievably, especially on the yaw.  I rarely fart around with the force trim and trim release on the heading when FD is off.  I might disable the yaw SAS channel when FD is off or just use turn-to-target.   Sometimes I'd just toggle the yaw channel to reset that diamond/caret thing.  But, heck, I rarely use the manual trimmer button.  If I'm really in a situation where FD off is screwing stuff up and I'm not in a turning-to-target sort of situation, I turn FD on and just deal with it being looser with the autotrim PIE script.

Edited June 18, 2021 by Reticuli

[Raptor9]

11 minutes ago, Reticuli said:

I'm assuming now that the Apache pedals do not center but that they have at least a little bit of tension in them so they aren't going to flop around on their own.  Correct?

 

The pedals have some spring tension in them, but only when the force trim is engaged.  Unlike some other helicopters, you can force trim the 64's pedals. When the force trim is interrupted, they do get much more loose.