Click here to access the Helosim website
SUBSIM Radio Room Forums

BUYING GAMES, BOOKS, ELECTRONICS, and STUFF
THROUGH THIS LINK SUPPORTS SUBSIM, THANKS!

The Web's #1 BBS for all submarine and naval simulations!

Go Back   SUBSIM Radio Room Forums > General > Helosim.com and Flight Sims

Reply
 
Thread Tools Display Modes
Old 05-27-2010, 08:35 AM   #16
Arclight
Navy Seal
 
Join Date: Jun 2008
Location: Land of windmills, tulips, wooden shoes and cheese. Lots of cheese.
Posts: 8,467
Downloads: 53
Uploads: 10
Default Dealing with a cranky engine

Every now and then, you'll have to deal with an engine that won't start. Whether it is because of damage or user error, there's 1 procedure you can try to get it back in order again.

It's called cranking the engine, and is used to purge excess fuel from an engine. Basically, you turn the engine without supplying more fuel, driving out what fuel is present already.


Technically, you should engage the rotor brake, but since we don't have to deal with braindead groundcrew wandering too close to our helo, I don't think it's nescesary.

What you do is use the normal start-up procedure with the start-up mode selector set to "crank" (switch next to engine selector, has 3 modes for: "engine start", "crank" and "false start"; up, middle and down position respectively), except turning on EEG isn't nescesary because you're not trying to fire up the engine, and you leave out the last part of opening the cutoff valve when the engine spools up to 20% (denying fuel to engine).

What you'll see is the start-valve light come on as normal, and the engine spools up to above 20% as normal (if it doesn't, you've got bigger problems). Again, don't open the cutoff valve at this point, just wait untill the light turns off and the engine spools down. Then set the mode selector back to "engine start" and start as normal.
__________________

Contritium praecedit superbia.
Arclight is offline   Reply With Quote
Old 05-27-2010, 09:04 AM   #17
Arclight
Navy Seal
 
Join Date: Jun 2008
Location: Land of windmills, tulips, wooden shoes and cheese. Lots of cheese.
Posts: 8,467
Downloads: 53
Uploads: 10
Default PVI-800 basics

The PVI-800 is your navigation computer; the big panel on your lower-right front, with the numbered buttons.

It has a lot of functionality packed into it, including the ability to send points (coordinates, basically) over the datalink to other flightmembers, but I'll just touch on some basic functions here.


1. waypoint mode:
If you look at the Abris in flight (and you set it to map), you'll notice the lines and waypoints forming a flight route. The autopilot isn't tied to the Abris, so apart from visual guidance on it's display and in the HUD, it doesn't help you get there.

But those waypoints are also stored in the PVI. If you press the "WPT" button (marked 1 above) and press a number, the corresponding waypoint is brought up and made active. Note that the first waypoint for PVI is not the airfield, but the actual first waypoint in the route.

2. airfield:
The position of the base/FARP you take off from is stored in the PVI as well. You can bring it up by pressing the "AIRFIELD" button, and then "1".

3. point mode:
In the editor, you can set targetpoints, typically placed at enemy positions. These points are entered in the PVI as well, and can be brought up by pressing the "NAV TGT" button and then a number. You should notice a numbered box popping up on the Abris display (given that it is visible, depending on scale setting).

4. wind
Nice and simple: press this button, and the top bar will display wind direction, and the bottom bar displays wind speed in m/s.

To set the PVI back to neutral and get the standard HUD back, just push the lit mode-button. It will turn off and no more data is supplied from the PVI untill you activate it again.


So, what good is all this? Well, for one, the HUD displays some more info: an indicator will pop up on the heading strip to indicate direction to your selected point, and on the bottom of the HUD you'll notice a range-indication. This is handy when combined with the point mode; given that a point is properly set to indicate enemy position, you can read out a range estimate from you to likely threats. Knowing a Strela SAM can reach out to about 5 km, and your Vikhrs to 7km (about 8km with the authorisation override), you can position yourself in striking range without flying into threat range.

Note that it kinda depends on how the mission is set up, but it's still a good tool to use to determine if your current firing position is likely to result in a smouldering wreck at some point.

Secondly, it allows you to engage the autopilot, and have it fly for you. And that's what I'll touch on next.
__________________

Contritium praecedit superbia.
Arclight is offline   Reply With Quote
Old 05-27-2010, 11:19 AM   #18
Arclight
Navy Seal
 
Join Date: Jun 2008
Location: Land of windmills, tulips, wooden shoes and cheese. Lots of cheese.
Posts: 8,467
Downloads: 53
Uploads: 10
Default Autopilot crash-course

Because the autopilot and trimmer are closely tied together, a bit on the trimmer and how the 2 relate first.


A trimmer sets control-surfaces to a user specified setting. For example, if you trim the rudder in a direction, it will stay like that until you change it. In the real KA-50, the trimmer "locks" the controls in place, and the same thing should happen if you have a force-feedback joystick. In the game, without force-feedback stick, it will remember your input, and use it as the new center-position for your controls.

Note that there's an option in the options menu that lets you change the behavior. Normally, as soon as the trimmer is released, any input at that moment is added to the new center-position, so if you have the stick pushed forward when releasing the trimmer, the nose will suddenly dip further until you center the controls.

The alternative method disables input until you center the controls, preventing the dip. But you might be turning the helo with trimmer down and accidentally release it for a moment; controls don't respond because you need to center first before making new inputs. Something to watch for, decide for yourself which method suits you best.


To use the trimmer, press and hold it down, then maneuver the chopper to your new course and attitude, and release the trimmer. The autopilot will use whatever control-authority it has (about 15-20% from max input) to hold current pitch, bank and heading. That means that if you trim the helo flying North and then try to change direction without trimmer, you first have to override that 15-20% input the AP will use to counter you, and you'll end up fighting (quite literally) the helo. And even if you manage to steer your new course, the AP will happily steer you back to the previous one as soon as you ease up on the controls.


Besides the 3 hold-channels, the AP has some other modes and functions, 2 of which can be seen near the 3 primary ones:


"ALT HOLD" engages the AP altitude hold channel. As with the other channels, it has only limited control, so if, say, 30% more collective is required to hold altitude, the AP will not be able to do so and you will lose altitude. So the best way to use this, and the other channels, is trim the helo to what you want it to hold. In this case, manually get your vertical speed to (near) 0 before engaging it. That way the AP has sufficient authority to make the necessary adjustments.

Note that any change in attitude requires re-trimming (preferably, have the trimmer held down when making these changes, as stated before).

Note also that this particular channel has an extra control interacting with it: the "collective brake". In the real KA-50, this needs to be pulled before you can make changes to the collective, to avoid dropping out of the sky after accidentally bumping it. It also has an "assign altitude" function, which is modeled in the game, and functions much like the trimmer.

Let's say you're in a hover, hover-mode and altitude-hold both engaged. To change altitude, press and hold the brake, increase or decrease the collective, level off at desired altitude (near 0 vert. speed) and release the brake. The new altitude will be sent to the AP and it will hold there (basically the brake acts as the trimmer for the altitude channel).

(alternatively, turn off alt hold, change altitude, level off and re-engage)

The first switch below the "FD AP" button is related as well: "BR" (up) tells it to use barometric pressure altitude, which is basically your altitude above sea-level. "RD" (down) tells it to use the radar-altimeter, which always gives you height above ground. The middle position sets this to auto (see just below).

The radar-altimeter functions to 300m above ground-level, after which it no longer gives a reading. If you have the altitude-hold channel active and set to radar-alti, the channel will essentially fail to function correctly because it is not receiving any altitude information. To get around this, leave the switch in the default auto position: radar will be used below 300m, and it will switch to baro-alti above that.

You may have realized that you can use the radar-altimeter and altitude-hold to get the helo to follow terrain automatically, but please remember that the AP has only limited input. It really can't manage with quick changes in height above ground, especially at speed. Be careful.


The "FD AP" turns on flight-director mode. You will see a change in the HUD, with 2 small horizontal bars popping up either side of the attitude indicator. It represents the currently trimmed pitch and bank.

It's function is this: in flight-director mode, the 3 main channels get different behavior. They no longer hold, but dampen, and in the case of heading-hold it is no longer functional at all. What it allows is a fair degree of free control without trimming for every little change. You can still use the trimmer to minimize the needed input, but the AP will not actively fight you when you try to deviate from it. On the flip-side, you now have to make corrections regularly to counter small changes in pitch and bank.

Personally I prefer this when going into combat; I don't have to worry about constantly holding down the trimmer to maneuver.

Note that since hold-behavior is changed to dampen, hover-hold will not work as well either.


Told you this thing was complex, didn't I?


Route-mode:
Route-mode works in combination with the PVI. It automatically flies the helo to the waypoint or targetpoint you brought up on it's display, while holding desired speed.

You can set whether you want to simply fly towards the waypoint (heading), or fly the exact line between 2 waypoints, or between a waypoint and a targetpoint (track). You control this with the 2nd switch below the "FD AP" button. "DH" (up; desired heading) position tells it to just steer the heading, "DT" (down; desired track) position tells it to follow the exact track.

Note that the AP will try to maintain your desired speed: if you want to cruise at 180kph, accelerate/decelerate to that speed, trim the helo to maintain that speed and engage route-mode. Changes can be made with the mode active by holding the trimmer, changing speed, leveling off to maintain that speed and releasing again (again, the AP has limited input available, so if the speed is different than desired, the helo is probably not trimmed close enough to the desired attitude. Also realize that any change in collective affects attitude as well; yes, more trimming).

Combine this with altitude hold for a nice, hands-off, perfectly level flight.


Hover-mode:
In hover mode, the AP tries to hold the helo at the same position and height, so as a result of enabling this, altitude-hold channel is automatically engaged as well. To use this properly, trim the helo for a hover first; reduce speed to near 0 and trim so it almost hovers on its own. Engage hover-mode and it will make the necessary adjustments to hold the helo in place without any further input.

It has a minimum altitude, which I think is 15m (more like 10m or 5m, but try to keep a margin for safety). Do NOT engage this mode below that altitude. Please don't try to land by descending from this hover; it will disengage at some point before touching the ground, leading to a failed landing if you're not prepared to deal with the suddenly needed corrections.

In the HUD, you'll see a small circle pop up, with a small square in the middle. Imagine looking at the helo from the outside, from above. The small square is the point on the ground you want to hover above, and the circle represents the rotordisk. If you drift forward, you'll see the square drifting down in the HUD (to the rear of the helo in this imaginative top-down view). The AP will always try to steer back to this point, centering the square in the circle (getting the center of the rotordisc exactly above the desired point). If the deviation becomes to big, the AP will pick a new point directly below the helo (you'll see a new square pop up in the HUD, centered to the circle, if the previous one drifts off to far).

If the helo has trouble staying on the spot, keep the trimmer pressed and refine your manual hover, then release to give the AP another shot at it.


Vertical descent:
It's an automated way of descending while in hover-hold mode. Press and hold the key to make a smooth descent at up to 2m/s. Once released, new altitude is sent to AP and it will hold that. It's useful because it has a limited rate of descent, avoiding any vortex accidents.

Should it not descent, or barely, you probably have the collective "trimmed" to high, so the AP can not give enough input to make the descent.



Think that's it... god, I hope that's it.
__________________

Contritium praecedit superbia.

Last edited by Arclight; 05-27-2010 at 11:38 AM.
Arclight is offline   Reply With Quote
Old 05-27-2010, 11:54 AM   #19
Arclight
Navy Seal
 
Join Date: Jun 2008
Location: Land of windmills, tulips, wooden shoes and cheese. Lots of cheese.
Posts: 8,467
Downloads: 53
Uploads: 10
Default Ballistics

On the auxiliary panel, rear-right, you'll find this bad boy:

It's the ballistics data settings selector. It has different modes that you need to set, depending on which type of unguided weapon you are using. If you're only carrying 1 type of rocket or gunpod, and it is mounted at the start of the mission (the helo "spawns" with it), it should be in the right postion.

If you change load-out during the mission though, or have different weapons on the inner and outer hardpoint (S-8 + gunpods, for example) it will need to be set manually:

0 - S-8 KOM / OM
1 - S-8 TsM
2 - S-13
3 -
4 - S-8 OFP2
5 - UPK-23
6 -
7 - FAB 250
8 - FAB 500
9 - KGMU AO
10 - KGMU AT

Failing to set it correctly will result in the targeting reticle not displaying in the correct place on the HUD.
__________________

Contritium praecedit superbia.

Last edited by Arclight; 05-29-2010 at 02:09 PM.
Arclight is offline   Reply With Quote
Old 05-27-2010, 12:13 PM   #20
Arclight
Navy Seal
 
Join Date: Jun 2008
Location: Land of windmills, tulips, wooden shoes and cheese. Lots of cheese.
Posts: 8,467
Downloads: 53
Uploads: 10
Default Speeds and banks

Abris has many useful pages, here's one of them:
__________________

Contritium praecedit superbia.
Arclight is offline   Reply With Quote
Old 05-31-2010, 05:09 AM   #21
HunterICX
Rear Admiral
 
Join Date: May 2006
Location: Malaga, España
Posts: 10,820
Downloads: 8
Uploads: 0


Default

I have the start up sequence printed out nicely for reference, thanks lionclaw for posting it.
I don't dare to flick switches at random with this sim
this thread is very welcome for a rotorrookie as myself, thanks all

also linked this thread in the sticky ''Flightsim hanger'' under tutorials and guides.

HunterICX
__________________
HunterICX is offline   Reply With Quote
Old 05-31-2010, 06:53 AM   #22
Lionclaw
Ace of the Deep
 
Join Date: Dec 2003
Posts: 1,058
Downloads: 5
Uploads: 0
Default

You're welcome.

It's good to learn how to operate the aircraft's many switches. It will take time to learn it all, just add a single helicopter in the editor and just practice manual startups and in time it will become second nature and you can do the startup by memory.
Lionclaw is offline   Reply With Quote
Old 06-01-2010, 07:39 AM   #23
Dowly
It's an alpaca, ok?
 
Dowly's Avatar
 
Join Date: Apr 2005
Location: Finland
Posts: 24,758
Downloads: 32
Uploads: 0


Default

Nifty Ka-50 Cockpit trainer from the Warhawk squadron:
http://war-hawks.net/Training/mod/re...iew.php?id=122

If it asks to register, click to login as quest.

Quote:
This post is to announce the release of a new Flash cockpit trainer for DCS:Blackshark. If you ever flew Falcon 4, then you are probably familiar with the cockpit trainer for that sim. This is very similar, but much more detailed. When you mouse over buttons, switches, and guages, a pop-up window will give a brief description of that item. Some items are clickable giving you an even more detailed description.
Dowly is offline   Reply With Quote
Old 02-03-2011, 08:26 AM   #24
Arclight
Navy Seal
 
Join Date: Jun 2008
Location: Land of windmills, tulips, wooden shoes and cheese. Lots of cheese.
Posts: 8,467
Downloads: 53
Uploads: 10
Default

Right, a basic helicopter concept that should help you understand the flying of it: you don't control the throttles directly, this is done by the aircraft's systems. Early helicopters did have manual throttles, making them particularly challenging to fly, but that's not what I wanted to tell you.

Instead of controlling the engines, you use the collective stick to change the angle (angle of attack is correct term iirc) of the rotorblades. The higher the angle, the more lift you get, but the blades get a lot more resistance as well. This will cause the rotor RPM to drop, which is picked up on by engine management, which will then increase engine RPM to compensate and get the rotor RPM back to it's desired level.

In other words, you do not control the engines to increase or decrease the rotor RPM; rotor RPM is a constant (theoretically; hard maneuvers can slow it down significantly and blade-stall is possible as well, just like a wing). All you do is manage the angle of the blades, and the engines are essentialy slaved to it.


There are situations you want to take the engines out of auto-throttle and just set them to max-power. Take-offs and landings come to mind, as well as emergency situations where you are losing altitude, especially if only 1 engine is operational.

Because of the way it's set up, there will be lag between your inputs and the engines throttling up to deliver the required power. Setting throttle to max avoids this.
__________________

Contritium praecedit superbia.
Arclight is offline   Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -5. The time now is 11:03 AM.


Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2021, Jelsoft Enterprises Ltd.
Copyright © 1995- 2021 Subsim®
"Subsim" is a registered trademark, all rights reserved.