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Horizon Line not horizontal


Belphe

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Hi,

As in the topic, both Cruise and Transition Horizon Lines are not perfectly horizontal with the canopy frame or well... the horizon. The screenshot is taken in a cold, empty helicopter with no head tracking just after spawning. Is the Apache that asymmetrical that it shows on the HUD?

Thanks

 

Horizon Line.jpg

Never say never, Baby!

 

[sIGPIC][/sIGPIC]

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You should see them in VR!

Jokes aside, I've had a problem with horizon lines in all of the HMDs on different aircraft. Really noticed it on the Hornet, and no matter how many times I'd run the alignment it never improved. I just thought it was me doing something wrong.

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  • 3 months later...

I am still completely confused, not by the reason they have a fixed horizon line. I get that you need to be able to know whether or not you’re diving to the ground or climbing too fast while you’re looking around for targets. 
 

I’m confused because the so called horizon line isn’t on the horizon. If you place your flight path vector on the clearly visual horizon as perceived by the your eyeballs and thus achieve zero feet per minute rate of climb then the flight path vector isn’t sitting on the horizon line……

What am I missing?

I am thinking/ guessing it’s got something to do with the “waterline bias set” on page 104 perhaps? I know that in my fixed wing assessment of whether we are going to pass over the top of a static cumulonimbus while we are in unaccelerated flight, we can use a transparent water bottle to see if the steady waterline is above or below the cloud tops. 


Edited by Willie Nelson

i7700k OC to 4.8GHz with Noctua NH-U14S (fan) with AORUS RTX2080ti 11GB Waterforce. 32GDDR, Warthog HOTAS and Saitek rudders. HP Reverb.

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  • ED Team
28 minutes ago, Willie Nelson said:

What am I missing?

The horizon line isn't a 1:1 scale ratio in pitch. When in Cruise mode, the horizon line/pitch ladder is a 2:1 scale ratio in pitch, and when in Transition mode the horizon line is a 4:1 scale ratio in pitch.

Afterburners are for wussies...hang around the battlefield and dodge tracers like a man.
DCS Rotor-Head

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5 hours ago, Raptor9 said:

The horizon line isn't a 1:1 scale ratio in pitch. When in Cruise mode, the horizon line/pitch ladder is a 2:1 scale ratio in pitch, and when in Transition mode the horizon line is a 4:1 scale ratio in pitch.

Thanks for getting back to me. Yes, I read that but the horizon line is still the horizon line and while I’m looking through it at something on the ground for example, how can determine whether or not I’m climbing or descending without reference to the VSI, in other words, is there a flight path vector equivalent that relates to this horizon line? If not, I’m not sure what it is useful for……

 


Edited by Willie Nelson

i7700k OC to 4.8GHz with Noctua NH-U14S (fan) with AORUS RTX2080ti 11GB Waterforce. 32GDDR, Warthog HOTAS and Saitek rudders. HP Reverb.

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On 4/7/2022 at 7:46 PM, colin11123 said:

Could ask the crew chief to check the tyre pressures

 

LOL, says system generated line is out of calibration so check the tire pressures?  I could see that really happening. 

We had a maintenance request once that said "relief tube too short". Seat mech went out and found that the relief tube was just wrapped around a bolt. On the Maintenance Action Form he put "CND, checks 4.0 with enlisted c**k".  LOL!  He was called on the carpet for it, but he said it was worth it.  Legendary.

It's a good thing that this is Early Access and we've all volunteered to help test and enhance this work in progress... despite the frustrations inherent in the task with even the simplest of software... otherwise people might not understand that this incredibly complex unfinished module is unfinished. /light-hearted sarcasm

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  • ED Team
7 hours ago, Willie Nelson said:

how can determine whether or not I’m climbing or descending without reference to the VSI, in other words, is there a flight path vector equivalent that relates to this horizon line? If not, I’m not sure what it is useful for……

Flying helicopters is all about maintaining an attitude. Attitude determines direction and magnitude of velocity based on where you are offsetting the lift vector from the main rotor system. How well a helicopter pilot can maintain an airspeed/flight path is predicated on how well he can maintain a specific attitude.

When performing an approach to landing in a fixed wing, you control speed by adjusting your pitch/AoA for speed with the stick and you control your flight path up or down with the throttle. Flying a helicopter is similar, in that you control your pitch attitude for speed with the cyclic, and you adjust your climb/descent with the collective. You can certainly use the cyclic to pull back into a climb or push over into a dive, but doing so will have drastic effects on your airspeed condition if maintained.

So to answer your question: yes, you should be using the VSI to determine your climb/descent rate or to maintain level flight, and the flight path vector to gauge your virtual direction of flight. The horizon line is only used as an attitude reference relative to the LOS crosshairs, which is why it isn't placed virtually over the real-world "out-the-window".

Afterburners are for wussies...hang around the battlefield and dodge tracers like a man.
DCS Rotor-Head

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11 hours ago, Willie Nelson said:

how can determine whether or not I’m climbing or descending without reference to the VSI, in other words, is there a flight path vector equivalent that relates to this horizon line? If not, I’m not sure what it is useful for……

I use the horizon line as a reference to determine my acceleration:

000.jpg

When my LOS Reticle is level with the Horizon Line (ref. C) it means that I am maintaining my speed. If the reticle is below the line I'm accelerating, if above I'm slowing down. If I want to make it pretty and levelled I keep my VSI at 0 (ref. D) and vertically align my Flight Path Vector with the Head Tracker (ref. A & B).


Edited by Belphe
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Never say never, Baby!

 

[sIGPIC][/sIGPIC]

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A set pitch attitude with a level vsi will result in a set speed. 90 knots is approximately “wings level”, I.e. the horizon line is level with the horizontal lines of the LOS reticle. 40 knots is about 1/4 of the way up the bottom vertical line of the LOS reticle. This equates to approximately 5 degrees nose up. This attitude is important because it is also the attitude of the helicopter sitting on the ground and while it’s at a hover. 70 knots is about 3/4 of the way up the bottom vertical line of the LOS reticle. 
 

I can be looking 90 degrees up, left or right, or even have my head rotated and still be able to Any of these attitudes because the horizon line reference is the LOS reticle. This allows me to look anywhere and everywhere and still maintain a constant pitch attitude, this is really important at night, when having to constantly look ahead or up/down to find the horizon line would be insanely disorientating. 
 

Long story short, set the pitch attitude and adjust the collective for a level VSI. Pitch is super important for a helicopter because the pitch determines how much thrust is translated to horizontal acceleration. 

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1 hour ago, bradmick said:

A set pitch attitude with a level vsi will result in a set speed. 90 knots is approximately “wings level”, I.e. the horizon line is level with the horizontal lines of the LOS reticle. 40 knots is about 1/4 of the way up the bottom vertical line of the LOS reticle. This equates to approximately 5 degrees nose up. This attitude is important because it is also the attitude of the helicopter sitting on the ground and while it’s at a hover. 70 knots is about 3/4 of the way up the bottom vertical line of the LOS reticle. 
 

I can be looking 90 degrees up, left or right, or even have my head rotated and still be able to Any of these attitudes because the horizon line reference is the LOS reticle. This allows me to look anywhere and everywhere and still maintain a constant pitch attitude, this is really important at night, when having to constantly look ahead or up/down to find the horizon line would be insanely disorientating. 
 

Long story short, set the pitch attitude and adjust the collective for a level VSI. Pitch is super important for a helicopter because the pitch determines how much thrust is translated to horizontal acceleration. 

Thanks that makes it much clearer. Of course I’m forgetting how much pitch varies for level flight in a helo.  

i7700k OC to 4.8GHz with Noctua NH-U14S (fan) with AORUS RTX2080ti 11GB Waterforce. 32GDDR, Warthog HOTAS and Saitek rudders. HP Reverb.

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10 hours ago, Willie Nelson said:

Thanks that makes it much clearer. Of course I’m forgetting how much pitch varies for level flight in a helo.  

It varies by 5 degrees in an Apache. 5 degrees to go from 40 knots to 90 knots. 6 degrees is about 110kts.

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I was previously thinking that the LOS reticle was meant to be representative of a Flight path vector in its relationship with the horizon line but it is not. It is a pitch indication with reference to the horizon line. I get it now. Thanks again. 

 

 

 

i7700k OC to 4.8GHz with Noctua NH-U14S (fan) with AORUS RTX2080ti 11GB Waterforce. 32GDDR, Warthog HOTAS and Saitek rudders. HP Reverb.

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