FA off strange issue with speed

BlindGuard · Mar 14, 2023

Good day cmdrs! Can you please tell me what am i doing wrong or do i understand wrong about how the FA-off system works. Because this misunderstanding almost cost me a destroyed ship in 1.5k LY from Sol when i was having fun in canyon FA off flying. Here's the capture of my flight.

What am i doing here:

0:14 Boosting my Imperial courier above the surface of a planet
0:16 Turning FA off
Rotating the ship 180 into opposite direction
0:24-0:45 Trying to engage thrusters by adding speed into opposite direction of my trajectory (you can see it buy blinking idicator bar near speed bar but nothing happens - ship is not slowing). To slow it down i have to turn FA on. Where is the mistake here? BTW sometimes it works, like 1 time for 3-4 tries. Or also i can start engage vertical thrusters for a second and then start again to press W and ship starts to slow down.

Theoretically i guess problem is that ship already knows that he has reached maximum speed in his vector moving that's why he does not accept any command to increase speed (even if this command is given into opposite direction of current speed vector) or not?

P.S I'm not sure but it seems that i didn't expirienced it before facilitate my courier to the state when he can reach 700 speed

Neilski · Mar 14, 2023

That's not what happens when I do what I think you're describing. Did you really try to use forward thrust from 0:24 to 0:45?

Northpin · Mar 14, 2023

BlindGuard said:
Rotating the ship 180 into opposite direction

0:24-0:45 Trying to engage thrusters by adding speed into opposite direction of my trajectory (you can see it buy blinking idicator bar near speed bar but nothing happens

After you turn 180 you need to use forward thrust to slow down.
For some reason, you seem to be applying reverse thrust which for your vector means increasing the speed.

BlindGuard · Mar 14, 2023

Neilski said:
That's not what happens when I do what I think you're describing. Did you really try to use forward thrust from 0:24 to 0:45?

I'm sure. Yes. I've expiremented for a half of an hour before post here. I'm not sure but it seems that i didn't expirienced it before facilitate my courier to the state when he can reach 700 speed

BlindGuard · Mar 14, 2023

Northpin said:
After you turn 180 you need to use forward thrust to slow down.
For some reason, you seem to be applying reverse thrust which for your vector means increasing the speed.

But i was pressing W which is always forward thrust on my control scheme. I can even add overlay with buttons i'm pressing

Northpin · Mar 14, 2023

BlindGuard said:
But i was pressing W which is always forward thrust on my control scheme. I can even add overlay with buttons i'm pressing

Well, by the movement of the cockpit it looks like you're engaging the lateral thrusters not forward ones (0:31-039)

Better recheck the binds/control scheme

Scratch that

Neilski · Mar 14, 2023

BlindGuard said:
But i was pressing W which is always forward thrust on my control scheme. I can even add overlay with buttons i'm pressing

OK that's super odd then.
Two things I can see on re-watching your video:

your thrust indicator blinks the same way mine does when I engage forward thrust (good).
your speed doesn't decay after the boost, pretty much at all (mine decays quite rapidly after the boost, no matter what I do - FA on/off etc.)

I think observation #2 means a bug is at play and that might be affecting the thrusters too...

[edit: in fact after a while the ship speed increases, which reminds me of some weirdness/exploits with letting a ship fall under a planet's gravity and achieving insane speeds. I imagine this isn't reproducible when not just above a planet's surface.]

Fixitman · Mar 14, 2023

I'd add the overlay, file a support ticket, and include a link to the overlay video in the ticket.

BlindGuard · Mar 14, 2023

Neilski said:
OK that's super odd then.
Two things I can see on re-watching your video:

your thrust indicator blinks the same way mine does when I engage forward thrust (good).

your speed doesn't decay after the boost, pretty much at all (mine decays quite rapidly after the boost, no matter what I do - FA on/off etc.)

I think observation #2 means a bug is at play and that might be affecting the thrusters too...

[edit: in fact after a while the ship speed increases, which reminds me of some weirdness/exploits with letting a ship fall under a planet's gravity and achieving insane speeds. I imagine this isn't reproducible when not just above a planet's surface.]

Exactly, i've mentioned that too. Guess it's because i was above the planet surface

Northpin · Mar 14, 2023

BlindGuard said:
Exactly, i've mentioned that too. Guess it's because i was above the planet surface

looks like speedbowling.
well, reverse speedbowling

since you are 180° turned, but it seems it doesnt matter because as soon you pitched down towards 5°, your speed started to increase

Morbad · Mar 14, 2023

Gravity does weird things to FA off, and has as far back as I can remember.

BlindGuard · Mar 15, 2023

Added the video with key overlay and with external view. As you can see with FA off and turning 180 somehow my forward-backward axis converted to up/down axis. You can see it by jet cones on my top maneuver engines that are pulling me down while i press W. Also when i boosted with pressed W i immediately recieved strong impulse to the ground. Sad story about crashing in distance more then 1.5 ly from station

Everything was made for science.

So i'm not wrong, it's a bug and i can go to issue tracker with that?

Northpin · Mar 15, 2023

I was not able to replicate that, but... i was using a Conda with a 360m/s top speed not a 700+ Courier (that's what i got in the system i doing AX)
my ship performed as expected, turning 180 then firing the forward thrusters having the expected result of reducing the speed. The planet is 0.19g so quite close

Edit: as a side note, for speedbowling nor ship type nor engineering nor top speed matters

Rebels Rogue · Mar 15, 2023

Cmdr Sanderling, has given a very accurate and eloquent explanation of your problem in your YT comments.
I will repost here for the sake of your thread and anyone else who may need an explanation in the future.

Cmdr Sanderling (Newton's Gambit)
This is often termed 'speedlock'. It happens when you're FAoff and you're going faster than the lock point for the ship/build you're in, and you're in descent. It's not a bug, but just a quirk of the flight model. It's how we have speedbowling competitions that FDev gave prizes for

The reason you couldn't slow down is because you were still in descent, and were trying to decelerate against your horizontal vector rather than the vertical (gravity) one. To break speed lock, you need to be in climb (any amount) - just boost into your verticals, and as soon as you're into positive range on the VSI - you'll be able to slow down. It's actually a really useful effect, as you can use a very small amount of negative VSI to maintain a boosted speed without re-boosting and wasting your capacitor needlessly. It's also dangerous as hell when you're low, if you don't have sufficient thrust/boost available to get back to climb rapidly. The FAoff model is kinda fun with nuances like this - but since most people never experiment with using it properly, there's limited info around. Manage your VSI carefully when fast, and you'll be fine. Just remember: No braking without climbing. Courier's pretty bad for it tho, cos very weak/short boost - plan accordingly.

Northpin · Mar 15, 2023

Rebels Rogue said:
Cmdr Sanderling (Newton's Gambit)
This is often termed 'speedlock'. It happens when you're FAoff and you're going faster than the lock point for the ship/build you're in, and you're in descent.

With the caveat that in the video from the first post they not descending, they're perfectly level so the speedlock should not happen
and in the second movie it seems that pressing Forward thrust seems to engage Down Thrust (?and also maybe forward too?)

Rebels Rogue · Mar 15, 2023

Northpin said:
With the caveat that in the video from the first post they not descending, they're perfectly level so the speedlock should not happen
and in the second movie it seems that pressing Forward thrust seems to engage Down Thrust (?and also maybe forward too?)

He is absolutely speedlocked from the moment he disengages fa-on and boosts. I imagine his top speed is 722 and that starts climbing which means he's in decent. The VSI res is very low but it indicates eventually.

BlindGuard · Mar 15, 2023

Rebels Rogue said:
He is absolutely speedlocked from the moment he disengages fa-on and boosts. I imagine his top speed is 722 and that starts climbing which means he's in decent. The VSI res is very low but it indicates eventually.

Thank you for adding post from Cmdr Sanderling - that is non-obvious behavior of the FA-off ship but i have to deal with it

But still strange for me is that when are speedlocked (as we've already figured out) and you go into 3d person view and start trying to make a horizontal thrust in opposite direction - your vertical thrusters begin to push you to the ground. That suicide behaviour killed me in last video

Rebels Rogue · Mar 15, 2023

BlindGuard said:
Thank you for adding post from Cmdr Sanderling - that is non-obvious behavior of the FA-off ship but i have to deal with it
But still strange for me is that when are speedlocked (as we've already figured out) and you go into 3d person view and start trying to make a horizontal thrust in opposite direction - your vertical thrusters begin to push you to the ground. That suicide behaviour killed me in last video

I'm not sure I understand what you mean, why would you go into third person? I think I missed a video

I think what you are saying is that when you are hurtling towards the ground and turn your ship 180 degrees and thrust nothing happens?
The problem with trying to turn the opposite way when you are speedlocked is fraught with danger. Problem number 1, your thruster don't work anymore, even rotating is going to be tough. problem number 2, remember you are now exceeding your speed cap so trying to thrust or even boost 180 degrees to the vector you are falling is not going to produce the energy to break the speedlock. If you are trying to do this for the first time don't try and go back the way you came just lift your nose above the horizon and boost. All will be well and you will get control back.
Unless you are coming down at 59 degrees, then you will need a different plan

BlindGuard · Mar 15, 2023

Rebels Rogue said:
I'm not sure I understand what you mean, why would you go into third person? I think I missed a video
I think what you are saying is that when you are hurtling towards the ground and turn your ship 180 degrees and thrust nothing happens?
The problem with trying to turn the opposite way when you are speedlocked is fraught with danger. Problem number 1, your thruster don't work anymore, even rotating is going to be tough. problem number 2, remember you are now exceeding your speed cap so trying to thrust or even boost 180 degrees to the vector you are falling is not going to produce the energy to break the speedlock. If you are trying to do this for the first time don't try and go back the way you came just lift your nose above the horizon and boost. All will be well and you will get control back.
Unless you are coming down at 59 degrees, then you will need a different plan

Probably you missed this video - i made the 2nd one. On 0:35 i jumped to 3d person view and started trying to deccelerate ship giving horizontal thrust in opposite direction to current moving. As you will see by jet cones - my vertical thrusters started to work and push me to the ground. But Keys responsible to vertical thrusters (R + F) were not pushed.

Morbad · Mar 15, 2023

I'm pretty gravity's ability to override the stricter velocity limits (the mechanisms by which speedlock and speedbowling are possible) introduced way back in the pre-release Beta 3 (November 2014, IIRC) is actually a bug. The fact that it's been around since the very first Horizons beta in 2015 is just evidence that they couldn't fix it without breaking something else worse.