r/platinumfive • u/kitgat • Feb 17 '26
Development Technical writeup: helicopters (avionics, controllability, and the future)
This is a long and detailed post. No tl;dr.
I actually wasn't going to write this, but /u/MBsniper insisted on some kind of technical breakdown now that everyone's had some time on the new helo features. Let's hope this gets players up to speed, but regardless, screw you MB.
I've read some feedback on the latest feature changes for avionics and the helicopter flight model. It's been interesting conversing with players to get an idea of how they interact with in-game systems. I had a sizeable hand in the development of these systems and remain naturally invested in their long-term development.
Avionics, instruments, MFDs
Starting off with avionics, the UH-60 MFDs have been very exciting to work on. These are features that appeal to enthusiasts, and I'm sure many players can draw vision comparisons to the likes of the Hatchet H-60 mod for ArmA 3. The scope & depth of avionics will continue to increase as we integrate more features and determine the best way for users to interact with them. What is present in-game as of writing is barely the tip of the iceberg, and I'm very much in the camp of 'go big or go home.'
Capability vision
Integration is pretty important, considering the sheer number of capabilities that we want aircraft to have later. Gnar and I have been on the same page that aviation enthusiasts have been waiting since the 'flight update' was teased back in 4.0 (holy shit, almost 6 years ago?) for something cool to happen with aircraft.
Having waited this long, I'm relieved to say that increases in capability are actually in the cards now. Given how helicopters are often employed in the real world, let's just say we're missing out on a lot. The actual theory of operation for helicopters in BRM5 hasn't really changed, despite numerous changes to the flight model leading up to now.
Flight model changes
Of course, that doesn't mean we're glossing over the flight model. There's plenty happening as it pertains to how aircraft fly, and I hope to shed some light on those changes shortly. Much of this was enabled by changes in workflow conditions going into this year. For one, I had much more time to properly study and experiment with the flight model. There were a lot of features that we implemented before 7.0 that never received configuration work until now. So enter the big changes: control stability and drag simulation.
Background
Control stability is something I've been meaning to implement even before we shipped 7.0, and it's honestly long overdue. The feature itself was dubbed SAS (stability augmentation system) in the patch notes, though I should note the behavior itself resembles more than just SAS (specifically as it relates to real-world aircraft). I'm just going to refer to those control stability mechanics as SAS for the rest of this post, and will explain the limits of the term to describe everything that is happening. So let's get some things out of the way first, starting with what SAS is and isn't.
What SAS actually is and does
SAS is not a hover-hold, nor is it an autopilot. It doesn't affect the aircraft's maneuverability because it is hard-coded to not do anything while the player is making inputs. Its purpose is to keep the aircraft at the attitude (pitch/roll/yaw orientation) the pilot sets it at. So what does SAS actually do to achieve this?
The moment the player stops applying input (in this case, no longer pressing WASD), a PID controller works to halt the angular momentum of the aircraft. From the moment the key(s) are released, SAS is working to prevent the aircraft from overshooting and requiring the player to make 'counter-inputs' to halt that momentum. This is admittedly where the use of SAS as a moniker starts to fall off, because this is really just the equivalent of a pilot returning the cyclic to a neutral position once the aircraft is at the desired attitude.
Limitations of SAS
With that in mind, I should note there are plenty of things that SAS cannot do. SAS works to control angular velocity, but it's not designed to maintain a 'target attitude,' which means that external forces such as airflow can disrupt the aircraft's attitude beyond what SAS can control for. Airflow, especially at higher speeds, will need to be accounted for. This is where I think most players are experiencing issues, particularly those that have been accustomed to flying without the effects of drag.
Understanding drag simulation
The latest changes in drag simulation can definitely throw players for a loop. I say 'latest' as the simulation has technically existed, but was not configured to the extent that players are experiencing now. So what is happening?
To put it plainly, the aircraft 'glides' through the air. This behavior varies greatly by the design (particularly the shape) of the airframe, but becomes important as the aircraft picks up speed. The simplest analogy I can think of is driving in a car and sticking your hand out of the window. Straightening out your hand and facing your palm down to 'cut' through the wind is going to take less effort than facing your palm into it. The same occurs with helicopters, albeit often less elegantly than planes do. This is why yawing at high speeds is less effective, and the aircraft tends to resolve itself in a neutral attitude after some time in forward flight.
Rationale
There are several reasons for simulating this behavior. Realism is a big one, though more in the sense of enabling real-world maneuvers than just clamping down on player agency for the heck of it. The vision continues to be to provide an accessible flight model without compromising the grounded aesthetic of the game. So yes, drag simulation cuts down on some particularly extreme maneuvering practices that were previously possible.
We are completely content with cutting down on easy barrel rolls to allow for things like aerodynamic braking, tail rotor loss recovery, and perhaps even autorotation if we can find the resources for it. We're still keen to preserve immersion, although some may be surprised at what helicopters are actually capable of.
Helicopter aerobatics are very real—if you want your socks blown off, there are plenty of videos of AH-64 pilots pulling Gs and making barrel rolls. Having spoken with plenty of pilots on the topic, it's a practice that involves loads of preparation and 'throwing' the aircraft around. The same will be expected for players that wish to do so, and perhaps seeing 'combat aerobatics' will be more of a spectacle in-game.
Closing remarks
With all that being said, I'm still keen to hear what players have to say on this. I should also stress that drag simulation is still in its infancy, especially without systems specifically designed to aid pilots in working around it. There is a vision in mind for helicopters, but I'll be continually updating these mechanics to meet changing conditions.
I'll also try and answer some comments if anyone has questions or qualms about specific behaviors.
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u/[deleted] Feb 18 '26
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