Why do ships sometimes just drop?

[Scoob]

Hey all,

I recall this issue from years ago, and it's still around...

I have a perfectly functional ship. It has adequate lift, and ample power output to sustain that. It's large and heavy, so quite sluggish to move *except* for its lift thrusters, which are very powerful.

Several times in a row now, I've been flying to a destination, I tap "c" to descend slightly (it had no upper thrusters, it relies on gravity) and it obeys perfectly. I start to slow, ready for final approach and landing, and tap "c" lightly once more and the ship is basically SUCKED to the ground very quickly, like ALL thrust has been turned off. Well, it's worse than that, it's like it suddenly has LOADS of thrust to push it down, like the thrusters have reversed. It's not survivable, I reload.

Visually, the thrusters are still working (Atmospheric, can see them spinning and the exhaust flame) but they act like they're turned off.

What might cause this?

Sanity check:

Ample thrust - check
Ample power - check
Thrusters ON - check
Ship not running out of fuel / battery - check

I use mods, so it's possible they do something they shouldn't. Just Encounter type mods and Weapon Core weapon mods.

More details: The ship flies fine, it took off fine - it has very strong upward thrust - and arrives at its destination. I then slow down to zero. I did this again just now and, it's when I come to a stop and hover for a few seconds that the ship just DROPS. It's using LESS power than it was in motion, but now it drops?

Playing this several times, just as the ship drops, power use climbs to 100%, but for no valid reason I can see. Puzzling.

So, when moving horizontally - lower thrusters providing lift, rear thrusters pushing it forward - it's fine. When it's slowing down - lower thrusters providing lift, fore thrusters slowing it down - it's fine. When it come to a halt, a few seconds later it drops like a rock.

I've tried many times now and, each time, there's this HUGE spurious energy spike that not related to anything actually suddenly drawing more power. Ship is using 58% power in straight flight - that's Five Large Atmospheric Thrusters providing lift and five Small ones pushing the ship forward. When slowing, there are four fore Small Atmospheric Thrusters slowing the ship down. Once halted, ONLY the Five Large Atmos are active, but power suddenly spikes massively.

This is weird, as the ship can take off *quickly* - so full power from those Five Large Atmospherics - and not draw even close to 100% Yet just coming to a hover suddenly goes crazy. This flight is unrecoverable, I'm going to have to revert to an earlier backup save.

Edit: Ok, this is turning into a commentary lol. I'm reviewing the ship's power systems, Reactors and Batteries. The reactors alone (two small) are just there to recharge the Batteries, *they* provide the main power for flight (short hops). While the batteries have ample charge - well they seem to - I'm adding MORE batteries and leaving the ship just charging for a bit, ensuring all batteries are at 100% before I take flight again.

The symptoms here are of a power *failure* i.e. the batteries ran out, but the UI suggest this isn't the case (I check charge levels). I wonder if a couple of the more depleted batteries just ran out, lowering the overall power? That would beg the question why some batteries have discharged faster than other though.

Still, I will over-engineer the solution here, seems fitting, and see how it goes.

[MARRA92]

I'd install a few parachutes and or try the ship in creative, only thing I can imagine is some thruster damaging some power component which lead to lesser output power and so the consumption turns into a major %.

[Scoob]

Originally posted by MARRA92:

I'd install a few parachutes and or try the ship in creative, only thing I can imagine is some thruster damaging some power component which lead to lesser output power and so the consumption turns into a major %.

Good thought, the thing (I captured it) did have parachutes originally, but they didn't deploy when I first shot it down, so took them off lol.

I've now over-spec'd the power - two additional batteries, given some time to recharge - and the ship is behaving better. I can only think that a couple of the batteries were somehow TOTALLY discharged (at the moment of the failure) whereas most were 30-40% full. That power dip of losing 30% of the battery output, tipped the balance.

I admit, I look at ONE battery and assume they're all the same, I cannot think why some would discharge more quickly than others. With "power remaining" being at an hour plus, suddenly losing power was... unexpected.

So, I think I've gotten to the bottom of why the ship lost power, just not why those (undamaged, I checked) batteries depleted long before the others.

[Capt Fuzzy]

If everything else that you've listed checks out, ample fuel, ample thrust, etc., then the only other reason that I can think of that would cause a ship to just 'drop out of the sky' would be accidentally hitting the Z key (inertial dampeners).
If you hit the Z key, you cannot hover, your ship will drop like a rock unless you either hit the Z key again, or lay hard on the upward thrusters (Space Bar).

[Scoob]

Good though, but not hitting "z". The symptom is like the ship suddenly loses power, so I think the uneven charge state of the Batteries is to blame. I.e. All Batteries with Charge = 50% power use, no worries and hours of power left. Several batteries out of charge = 100% power use, but still hours reported as remaining.

As I mentioned, the uneven discharge of the batteries is suspect here.

[herrschaftg35]

If power is the issue, than the energy bar on your hud will turn red when it begins to fall. Easy way to test this is to turn off the "low" batteries and attempt to take off. Doing the math will also help.

Batteries:
Small-grid: 200KW & 4MW
Large-grid: 12MW

Atmospheric Thrusters:
Small-grid: 600KW & 2.4MW
Large-grid: 2.4MW & 16.8MW

[CynicDragon]

never use the "P" key

[bossbill1]

You say it has no upwards facing thrusters i.e. No down pushing thrusters, So why are you pressing C ?...If I am thinking correctly when you press C to acitavate downwards thrust the lift thrusters (up thrusters) stop thrusting so the downwards ones can push you down.
Effectivley cutting all lift untill C is released and the up thrust can kick back in ( providing you have the dampeners on ).
This would explain the feeling you have that all thrust has been turned off. It could be that when the large up thrusters kick back in is whats causing the spike in power usage.
I would personally not use The c key but just put the ship in a nose down position and use the forward thrusters to push you down, basically fly to the ground... this would leave your main upwards thrusters running all the time controlling your decent.

[Ronin Planetary Industries]

1. Thrusters
a. One (or more) upward thruster is overridden and it's not enough thrust to keep the ship in the air. The game will ignore the rest of your upward thrusters' inertial dampeners and you will fall.
b. You're using atmospheric thrusters and you've left your upward hydrogen thrusters on, your hydrogen tanks off, and your O2/H2 Generator(s) on and there's not enough hydrogen production to keep the hydrogen thrusters fully supplied. Your ship will then start falling even though there's enough thrust for the atmospheric thrusters.

2. External grids
a. The more mass that's on a sub-grid or sub-grids then the higher the chances of your ship falling or tilting. Sub-grids are any grids attached via rotors, pistons, or hinges.
b. Attached grids. Grids that are attached via magnetic plates/landing gear or connectors can cause the same issues as sub-grids.

[Scoob]

I did do the maths and, if two or more batteries fail, then that can cause sufficiently low power to not be able to fully power the lift thrusters.

Still, if the Thrusters working at FULL power to initially lift the ship barely touch 50% power used, why they suddenly lose ALL power when a battery runs out doesn't seem quite right.

In theory, even with two batteries out, there was ample power output to hover, if not lift at full power. I don't know how nuanced SE's power usage is based on Thruster load. I.e. I'd assume a thruster actively lifting is using 100% power, whereas one just holding a hover would be using far less, depending on mass of course.

Basically, is a Thrusters either On (100% power) or Off (0% power) or is there a scale based on actual Thrust demand? Game was behaving like the former, but I expected the latter.

While it does seem that two of the batteries becoming empty, while others still had ample charge is what caused the issue, I still don't quite understand why the lift Thrusters appeared to lose ALL power as, even at half power, they should have been able to hold a hover just fine.

Now ship has what seems to be excessive batteries, and I left the ship for a couple of hours for the three Reactors (small) to charge said batteries, I've not had a problem. Power use still shows about the same, battery life (overall, shown in the lower-right HUD) is about the same. So, it looks like there's little difference...except ship doesn't periodically drop like a rock now lol.

Btw: none of my atmospheric vessels have thrusters to push down, they rely on gravity and work well. A gentle short tap of "c" is advised when a ship gets heavy though :)