Gravity for loaded cargo inverted?

[Wilbus]

Not sure if this has been posted but I noticed something weird about the cargo. 

First of all, I've had just a short time in the module and been clicking around rather than reading the manual. I managed to load up some cargo, a bunch of boxes and I also managed to unlock it all in the air as I wanted to. Now, with everything unlocked I started to climb to see if it fell out but it didn't, it did however shift from side to side so the unlock procedure worked. So I thought, what if it's inverted? So I put her in a quite steep dive instead and quite right, all the cargo decided to slide out the back while in the dive. 

Anyone else tried this? I would seem the gravity kind of works in reverse here. 

[ECTAE]

yep, noticed on the CARP tutorial too

got it on video

[H60MTI]

I'm not the only one who noticed that?

[winghunter]

did it behave like this? (timestamp)

 

Edited yesterday at 12:40 PM by winghunter

[ECTAE]

yep

 

[AusGoose]

Investigating internally, thanks!

[Wilbus]

Ok thank you all, so I am not going crazy! 

Yeah it behaves exactly like on the video  

Edited yesterday at 02:06 PM by Wilbus

[JNelson]

8 hours ago, winghunter said:

did it behave like this? (timestamp)

 

I'm not on the C-130 team so take my opinion with a grain of salt.

It seems like the behaviour is correct, when you pitch over you have very little g, meaning the forces that would normally cause the crate to slide down hill are much lower (not to mention the actual slope is not that steep initially). At the same time the aircraft is accelerating. Supporting this when you reload the plane you see the second crate moves forwards again a bit.

Whether the crate slides forwards or aft in the plane depends on exactly this balance of the acceleration of the plane, the gravity component down the ramp.

 

[Nodak]

Having been a loady on starlifters and herc's way back in the 80's and 90's cargo moving forward should never even be a possibility, there's always going to be some sort of system preventing it, whether rail locks, physical block, or a strap gate.  The side to side stuff shouldn't be happening either, the CDS was the most dangerous loads where there was a possibility back in my day because they were vulnerable to twisting and thus jamming up on the way out.  The rollers only allow easy forward and reverse motion, not much lateral.  If you are having lateral forces your not flying within acceptable parameters and won't be dropping any way.

At drop speeds with partial flap, it's always a down hill exit that rapidly picks up speed as the load rolls out, you had to be careful you didn't end up falling out by keeping a hand hold and slow controlled walking speed with a clear unobstruced floor on an empty plane, cause you could easily exceed stopping speed yourself on foot and end up falling out.  The typical load ripped out so fast you'd better have your visor down because the dust and debris it whipped up was getting in your eyes.  

What's missing graphically is the drogue chute system, those platforms aren't ever free rolling to begin with.  We didn't free fall stuff, it got extracted.

[Nodak]

 

That's how it actually works, there's a little bomb rack above the ramp that releases the initial platforms drogue chute, that platform has the next platforms drogue chute tied with break away tape to it's forward end with a long heavy nylon riser to rip it out for next ones deployment, than it pulls the next platform in sequence till all are gone. 

That chatter sound you hear are the platform locks on the rail giving way, they're spring loaded to a set tension one way, out.  They can't be overcome by forward motion, but sheared off maybe in a crash.

Edited yesterday at 10:37 PM by Nodak

[winghunter]

17 minutes ago, Nodak said:

Having been a loady on starlifters and herc's way back in the 80's and 90's cargo moving forward should never even be a possibility, there's always going to be some sort of system preventing it, whether rail locks, physical block, or a strap gate. 

 

Do you have an image of the rail locks? our understanding is that the J CDS doesnt have anything like mechanical locks.

The extraction chutes will be added soonish, they're modeled but not visible yet

[Nodak]

Correct, CDS doesn't use rail locks, why there's a limit on the container size and weight.  But they used gates to prevent forward motion, and a break away strap on the rear that is designed to fail at the correct time.  Also they are going to be located as far aft as the center of gravity allows for minimum travel out.

One had to be instructor qualified to drop CDS in 141's, never did it myself, but did everything else.  They were more a SHTF type drop.

[winghunter]

how do those gates look like ?

we thought about adding the straps but they would be very clumsy to setup and block player movement

[dresoccer4]

43 minutes ago, Nodak said:

If you are having lateral forces your not flying within acceptable parameters and won't be dropping any way.

welcome to DCS . we will be flying outside of acceptable parameters and we will be dropping everything. i'm excited to try my first inverted drop

[H60MTI]

Definitely need the drogue chute and the "gravity" thing fixed. Hard to do low level drops if I have to nose dive to ditch the cargo.

[Nodak]

Think it would be fine just to keep them from rolling forward, I had limited exposure to CDS stuff and that was over forty years ago in a long obsolete and retired air frame.  It was still a relatively new thing under development in the early 80's, at least in Starlifters.  Back than CDS was the flag pole local flying stuff in C-141's combined mainly with pilot and Navigator training, it could be done locally right on the Fort Lewis base ranges. 

The real cargo drops had to be done out at Moses Lake.  They rarely dropped more than one or two CDS containers at a crack, it was considered extremely dangerous to drop a full compliment of containers and the jet wasn't allowed to ever be filled to capacity anyway, it had a limit how many, and I don't remember what it was, way to dangerous even in combat, hence a required instructor loadmaster rating.  If it was that critical to get a major supply drop it would be delivered platform or load extracted anyway. 

I never flew a single training local except one air refueling pilot trainer with a butt load of cement blocks on pallets over Washington states mountain ranges.  In the Starlifter you basically did all your training at the school level at Altus AFB than finish within real world ops with an instructor.  Not like the Herc community flying many missions specifically scheduled as training.  CDS was the one exception to that, those air frames just weren't available with that sort of down time prior to the C-17's showing up.  They kept just enough people qualed on it to teach it if it had to be done, everyone knew it was ultimately a one way ride in that days cold war environment.  

[Someone]

12 hours ago, ECTAE said:

yep

 

So i just watched your video. The main issue here is that you dont have any deck angle when they are released. While you would normally drop flaps to be level, when you are doing a cds drop like this, you actually are looking for around 6 degrees of nose up attitude/deck angle. This is what gets the cds bundles rolling out.

Having said that, Im going to reduce the friction coefficients a bit in the next release, as stuff should be moving more quickly.  

1 hour ago, H60MTI said:

Definitely need the drogue chute and the "gravity" thing fixed. Hard to do low level drops if I have to nose dive to ditch the cargo.

You dont need to nose down to drop cargo.

[H60MTI]

I'm having the same issue with the pallets sliding forward also so, I need nose dice to "drop" pallets.

[Jenrick]

@H60MTI how are you dropping, manually hitting the jump button, or using the computer option?  

 

@Someone Ah, good to know the CDS should be moving faster, I have noticed that using the computer option the cargo seems to be taking a few seconds too long to exit the aircraft.  With everything consequently going long.

Edited 16 hours ago by Jenrick

[H60MTI]

Right now a combo of 3 different things...I've tried the CARP, can't get it to work. I'm assuming it has something to do with the flight route in the CNI or can't figure out how to activate it. I've tried using the Geronimo lights for a manual drop and then having to nosedive. I've also gone in the cargo and just unlocked all the containers and nosedived. Doesn't really end up well in any of the cases.

[DD_Friar]

9 hours ago, Jenrick said:

0MTI how are you dropping, manually hitting the jump button, or using the computer option?  

This is something I am also trying to work out. 

I have seen the CARP video but am trying to figure out a manual drop by either the pilot or the load master

[ECTAE]

11 hours ago, Someone said:

So i just watched your video. The main issue here is that you dont have any deck angle when they are released. While you would normally drop flaps to be level, when you are doing a cds drop like this, you actually are looking for around 6 degrees of nose up attitude/deck angle. This is what gets the cds bundles rolling out.

Having said that, Im going to reduce the friction coefficients a bit in the next release, as stuff should be moving more quickly.  

You dont need to nose down to drop cargo.

Yeah, I was at 0º (flaps 50) to the horizon when I pressed the green light. But as you can see in the video, when I realized it wasn't dropping, I pitched up to 6º (then 10º, which on an airliner is the kind of angle that would make a trolley go down the aisle uncontrollably,then I pitched up 20º), and the cargo literally went up. That’s literally against the laws of physics. It's not about friction coefficients— you guys need to redo the script, because I'd say the friction is actually acting in the opposite direction. At some point, your μ>1.

I'm not saying the cargo isn't dropping well as if you met those exact parameters, but if the condition necessary to tell the script to invert those friction conditions is having the plane at 6º when the green light is on, that's a different story. However, physics are clear—no cargo should go up when pitching up by 20º.

Edited 10 hours ago by ECTAE

[AhSoul]

I thought it was the TOW delivery mode that uses chutes and the CDS delivery mode was just gravity?

[Jenrick]

Messed with things last night.  So per the tutorial mission, drop config is 10 degrees flaps to get a 7 degree deck angle.  If you're flying along steadily, then either computer manual activation of the cargo release it works fines.

However.....  I jumped back to the Loadmaster view to watch the cargo on a run where I was flying completely manually, and realized I had let the deck level out, when the drop signal hit.  Popped back up front to pitch up a bit, and when I went back to the loadmaster view, sure enough the cargo was going up hill in a 7 degree climb.  I'd hazard there's either a flipped vector in the calculations, or the code was written to always start off with the assumption the deck is angled leading to a flipped vector.  Did some more testing, and so long as the deck is angled nose up when the release is activated (manual or computer), cargo exits just fine.  If it's level or nose down you run into the above issue.

7 hours ago, H60MTI said:

I've tried the CARP, can't get it to work. I'm assuming it has something to do with the flight route in the CNI or can't figure out how to activate it.

Make sure you enter an obstacle clearance height on page 4 of the CARP INIT, I was having similar issues till I realized that had to be set to generate a full CARP plan in the CNI.

Edited 3 hours ago by Jenrick

[Someone]

There are two factors at play here, both of which matter equally for the cargo to exit:

1) the deck angle. as discussed above, the deck angle should be 7 or so degrees.

2) The acceleration of the plane, relative to the cargo, post unlock.

If you are flying level, and unlock the cargo, it wont move. 

If you THEN pull the nose up, you are increasing the deck angle, but you are ALSO decelerating. When the plane decelerates relative to the cargo (which is now unlocked, and not attached to the plane), it will move forward, relative to the airplane.

 

So, yes, the deck produces a component of acceleration, but not enough to trump the acceleration of the plane, relative to the cargo. When you nose up abruptly, you slow, and it moves forward. 

When you nose down, your plane is accelerating AWAY from the cargo, and it can come out.

Edited 3 hours ago by Someone