While flying helicopters with forward airspeed, they do not gain altitude when via pulling back on the cyclic stick (Default S)as they should. This should take effect when pulling in collective (Default Q) or leaving the collective neutral. The same is true for decreasing altitue via pushing the cyclic stick forward (Default W) with no change in collective movement.
Edit: please mark this issue marked with latest dev build as of today.
This is easily noticable when attempting "Nap of the Earth Terrain Flight" (aka TERF). While approaching a hilltop or ridgeline and attempting to maintain the same altitude while going over it, you should be able to maintain the same collective stick setting while simply changing the pitch attitude of the helicopter and "trading altitude for airspeed" and vice versa when you want to decend on the other side of the hilltop or ridgeline.
Also, these current flight physics cause the player to almost come to a complete stop/hover before being able to gain enough altitude to clear the obstacle. This could be game breaking for me.
Even while pressing he "collective up" key.
This thread may be dead, but here is what I think your issue is. I believe what you are experiencing here is a product of the ArmA flight model's "semi-auto collective" (as I like to call it) to simplify flying for M+K pilots.
When using keybinds for the digital collective raise and collective lower (simply listed as "collective raise" and "collective lower" in the key bindings), the flight model will attempt to keep you in level flight (relative to sea level) when changing helicopter attitude, even if you don't touch the keys to change collective. To replicate this, you can take off, sit in a hover, and then slowly pitch forward. If you do it slow enough, you will achieve forward flight without losing any altitude.
You will only experience altitude change when adjusting attitude if you pitch or roll faster than the collective can catch up (it takes time for collective to change) or if you exceed an attitude in which there is sufficient vertical lift vector for the helicopter's rotors to keep you level.
If you press and hold the collective raise or collective lower keys, it will adjust the collective all the way to maximum or minimum, respectively. When you release it will go back to the collective level for level flight. Tapping the key will cause it to bounce back and forth between these values, depending on how long it is held.
If you seek the results that you desire, use the analogue collective key binds. I'm not sure how they would work with a keyboard since you have no way of knowing what level your collective is at, but it works just fine with an analog throttle peripheral.
As said above, this is only apparent with digital collective input. I also use analogue collective with a joystick throttle. Not only does it stop the "auto" collective, but produces a much greater collective response range as well.
Initially I had mistakenly bound digital collective to my throttle and it was terrible. Once switched to analogue it transformed collective response.
That, however, does not mitigate the current horrible flight model much, with its lack of inertia, excessive acceleration and lack of auto-stabilisation that modern helicopters possess ... but that is another issue.
This happens with both digital and analog key binds. Attempted with keyboard and mouse flying, Saitek X52 Pro flight controller joystick and with Thrustmaster Dual Power 2 controller. Seems pretty similar to other issues reported.
Seems to be resolved in latest dev build (0.71.107443). Although, the aircraft are extremely sluggish to cyclic input now. In particular, the Ghosthawk in the roll channel of flight.
Thank you for helping us improve the game!
Was hopefully solved as part of http://feedback.arma3.com/view.php?id=9786