There is tree main types of weapons modelled for the Mi-24 in EECH, fixed unguided weapons (rockets and UPK-23 gun pods), Yak-B gatling gun in nose turret and the Shturm (AT-6) anti tank missiles. The main aid of firing all these weapons is the HUD sight. This page explains how to use them.
Fixed unguided weapons
The Mi-24 can carry three types of rockets (S-5 57mm rockets in pods of 32, S-8 80mm rockets in pods of 20 and S-13 127mm rockets in pods of 5). It can also carry UPK-23 gun pods, with each pod carrying two GSh-23L 23mm guns with a combined firing rate of around 3500 rds per minute and 250 rounds of ammunition (which means all 250 rounds takes less than 5 seconds to fire). The rockets and gun pods are aimed and fired the same way.
The HUD sight for fixed unguided weapons
The HUD sight shows cross where firing the selected weapon will at a given range. The range is shown as a winding bar around the aiming cross. It has tick marks for every 1000 meters out to 4000 meters.
The sight will itself adjust range, and it does this by triangulation. This method assumes that the ground is flat, and if the helicopters is fairly high or in a dive this method works very well. But it's important to know that it does not work very well over hilly terrain, or if the helicopter is flying low or firing at a shallow angle at a target far away. If this is the case you have to adjust for that when aiming, or may even prefer the backup which doesn't adjust for range at all. And it doesn't not work at all for airborne targets.
Assuming the conditions are good for the range calculations it's a simple matter of putting the aiming cross over the target and firing. The rockets have fairly wide dispersion, so even with the best of aiming they may hit a significant distance from the aiming point. Therefor it's better to fire many rockets in salvos. The gun pods have much less dispersion and as such is much better suited when accuracy is needed.
The backup sight
The Mi-24 also has a backup sight (accessed by pressing O). All this sight does is show you what is straight ahead, and you have to adjust for range yourself. Still, this sight may be preferable when the ballistic sight is unreliable or against airborne targets. Or of course if the HUD sight fails due to damage.
Firing the Yak-B nose gun
The Yak-B is a four-barrell 12.7 mm gatling gun mounted in a turret in the nose. It has a firing rate of around 4000 rounds per minute, and 1470 rounds of ammunition (altough in real life more 500 than is rarely carried; that is on avarage as many as it will be able to fire before the gun jams). It's able to traverse 60 degrees to each side, 15 degrees up and 60 degrees down.
In the real Mi-24V the nose gun can be aimed, slewed and fired by the gunner in the front cockpit. It can also be fired by the pilot in fixed mode (i.e. firing straight ahead). Both modes are supported in EECH, but since only the pilot's cockpit is modelled aiming in slewed mode is fairly primitive.
The fixed mode is the default, and is aimed just like the fixed weapons described above. To enter the slewed mode press the key for the helmet mounted sight (PgUp). The gun will now fire in the direction the pilot is looking, up to the gun's traversal limits. There is no aiming help, so you will just have to see where the bullets hit and adjust your fire. The slewed mode is also used when using the EO sight (PgDn), and it will then fire in the same direction as the EO camera.
Firing Shturm missiles
The Shturm (NATO codename AT-6 Spiral) is a radio guided anti tank missile with a range of around 5 km. The Mi-24V, which is the model simulated in EECH, was the first Hind model capable of carrying this missile. The Ataka used on the Mi-28 is a further development of the Shturm.
The Shturm missiles is aimed with the EO system. So either use it yourself with PgDn and lock onto a target or ground point. Or cycle through the targets the co-pilot has discovered by using the next/previous target commands.
The HUD will show an aiming cross over the target/locked point if it's inside the HUDs view limits, and it will also show triangulated range to that point, like for the gun sight.
When you have a green ready light you can fire the Shturm missile. You can also fire if the range constraint is not met, since the range isn't accurate in any case. The missile requires continuous radio guidance, so keep the target locked until the missile hit (or miss). You can change target/aim point while the missile is in flight, and the missile will try its best to hit the new target.
Below the HUD and on each side are two lights. These lights are used to give the pilot some aiming status. The top green light on the left tells the pilot that the sight is active, and the selected weapon is ready to fire. The red light below is an advisory light that the range to current target is below minimum range or beyond maximum range of the selected weapon. Since range is not accurate the pilot may ignore this light if (s)he has reason to believe otherwise.
The top red light on the right side is used to indicate that the current weapon is not ready to fire. This only happens for the Shturm missiles when firing constraints are not met. The target is most likely outside the missiles firing limits, so manouver to position the target towards the centre of the HUD.
Co-pilot target help
If Co-pilot target-ID in the options menu is set to something other than 'OFF' then in the gun and rocket mods there will be a little circle over the current EO position (over target if a target is locked), to help you find the target and know what to aim for. Also the ID the co-pilot has identified will be named at the bottom of the HUD. Both of these are cheats that the real Mi-24 HUD doesn't have, but it does somewhat make up for not having a second person in the front cockpit to help you.