Horizons Flight assist and gravity, or "(DON'T) do a barrel roll"

Gédéon_Lecanard

Gédéon_Lecanard
Sorry if I'm late to that party, but I just noticed something funny, regarding the way flight assist handles gravity.

If you didn't notice already, flight assist compensates gravity on a planet (at least when you're not zoom speeding toward the surface). This translates in one noticable effect: in horizontal flight (hoover or mobile), thrusters will act so that your ship tends to stay at the same altitude, the same way a correctly trimmed helo would. If you disable your flight assistant, gravity will remind you fast enough a few rules about forces, masses and all sort of pesky details that'll splat your hull on the ground if not dealt with. So thanks, flight assist.

Now, for the fun part. The flight assist implementation is incomplete. Either that, or its gyro component is as old as my nokia phone, and simply won't know what to do with roll axis. Because it will only act as if your ship was belly face to the ground all the time. "Do a barrel roll", and you'll notice the helo analogy was quite accurate: only the below thrusters will stay active and ensure you meet the ground close and personal. Other thrusters will never kick in to compensate. (false statement here, see below)

Is it by design, or has FD never thought of us looneys who loves flying upside down so the sky won't fall on our heads?


Edit: the part in bold and italic is completely wrong. Sorry about that. Instead of cowardly editing it out, I'd rather underline to teach myself about extensive tests and correct use of external camera next time)
 
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777Driver

777Driver
Thrusters below the ship provide the required thrust to overcome gravity either automatically with FA-ON, or manually with FA-OFF. In a roll you need to compensate with positive pitch - main thrusters (also works straight and level FA-OFF) once you hit the 90 degree roll mark you wont have sufficient thrust to maintain altitude.
 
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Gédéon_Lecanard

Gédéon_Lecanard
Hey you're right. And they do kick in and try to compensate when upside down, I was wrong. Which means that up and lateral thrusters don't have the same power output as down thrusters. Why not. That's odd, since they do while in zero G, but well. I'm curious to know what has driven FD for this choice.
 
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777Driver

777Driver
Gédéon_Lecanard said:
Hey you're right. And they do kick in and try to compensate when upside down, I was wrong. Which means that up and lateral thrusters don't have the same power output as down thrusters. Why not. That's odd, since they do while in zero G, but well. I'm curious to know what has driven FD for this choice.
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Most simple answer is 'control laws;, it works the same in reality, you fly the software, the software fly's the machine. We don't have full control over thrusters output, even with flight assist fully disengaged hal9000 dictates thruster output and limits.

In a zero G environment the thrusters are never used to their full limit (we know this because thrusters are overcharged when on planets) It could well be that the downward thrusters are capable of providing more thrust than the other maneuvering thrusters, just artificially limited in zero or low G environments.
 

Windscreen Smudge

W
Thanks for catching yourself OP. Saved me the time of having to post a screenshot of my ship hovering 5 feet above the surface with the nose pointed directly down.

Flight assist is working exactly as it should.
 

Gédéon_Lecanard

Gédéon_Lecanard
Windscreen Smudge said:
Thanks for catching yourself OP. Saved me the time of having to post a screenshot of my ship hovering 5 feet above the surface with the nose pointed directly down.

Flight assist is working exactly as it should.
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If you take a screenshot of your ship hovering with the nose pointed directly down, you won't hover for long :D
Even if you're in control, given a high enough gravity, you won't be able to stop your descent. Flight assist on or off, only regular and down thrusters can overcome gravity in all currently known situations.

So it works as designed, sure, but "as it should" is definitely debatable. While I'd tend to accept 777Driver explanation about the overcharged thrusters, one could still wonder why only down thrusters would be able to perform such a feat. If all thrusters were equal in power (and why would they not be), the afore mentioned design would be faulty. In most airplanes, FBW systems are bypassable.
 
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777Driver

777Driver
Gédéon_Lecanard said:
If you take a screenshot of your ship hovering with the nose pointed directly down, you won't hover for long :D
Even if you're in control, given a high enough gravity, you won't be able to stop your descent. Flight assist on or off, only regular and down thrusters can overcome gravity in all currently known situations.

So it works as designed, sure, but "as it should" is definitely debatable. While I'd tend to accept 777Driver explanation about the overcharged thrusters, one could still wonder why only down thrusters would be able to perform such a feat. If all thrusters were equal in power (and why would they not be), the the afore mentioned design would be faulty. In most airplanes, FBW systems are bypassable.
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Back in early alpha a few of us requested a complete bypass of the control laws (direct law) As it stands one of the devs had to really push for a secondary law, the chances of us getting a 3rd direct law is non existent. Completely bypassing the computer's would cause havoc with the current gameplay mechanics.

I'm coming at it from a different angle to you, why would the thrusters all require the same output? These ships are designed to hover/land upright. From a design point of view the bottom and main thrusters require the most power.

I do a lot of canyon running in the ieagle/Viper/Courier, those ships have a high roll rate and can handle inverted flight for short periods, I can't think of any reason why I'd fly my T9/Anaconda/Cutter inverted.
 

AJW

AJW
If you actually did a barrel roll, as opposed to a normal 'aileron' roll, you wouldn't use the upper thrusters anyway. A true barrel roll is a positive-G manoeuvre in which the aircraft follows a helical path, as the pilot pulls back on the stick all the way through. An properly-executed aileron roll on the other hand involves the aircraft rolling on its own axis while following a straight path, which requires the pilot to push the stick forward as the aircraft goes through the inverted portion - at which point the pilot is hanging from his seat belt. The 'do a barrel roll' meme is based on a video game where they got it wrong: http://knowledgenuts.com/2014/01/26/difference-between-barrel-rolls-and-aileron-rolls/

For evidence that positive G (i.e. pushing the pilot down into his seat) continues all through a barrel roll, see this famous video sequence featuring Bob Hoover, where he pours iced tea as the aircraft rolls:
http://www.wimp.com/legendary-pilot-pours-himself-a-cup-of-tea-while-flying-and-doing-a-barrel-roll/
 
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