not a bug Rearm and Refuel

[Pribs86]

I'll do the best I can to describe this since I don't have any screenshots, video or data. I can only speak for the center tank because that's all I've used. In the F/A-18C, you can take off, burn the center drop tank, land with it still attached, rearm and refuel and it will put a full, fresh, tank on the A/C so you have full fuel when you take off again. If you do this exact same procedure in the F-16C you will NOT get a fresh center tank it will be empty. You either have to remove the tank in the rearm and refuel menu then add it again in the rearm and refuel menu (so you have to rearm and refuel twice every time) -OR- you MUST jettison the tank in flight. It will NOT give you a fresh, full, tank when you rearm and refuel with it attached from the previous flight even though the rearm and refuel page shows a center fuel tank attached. It will be empty. I have tested this many times and it's like clock work. 100% every single time. Like I said I have not tested this with the wing tanks though.

 

Thanks!

Edited August 4 by Pribs86

[Tholozor]

Try opening the AAR door, this will depressurize the external tanks.

[Pribs86]

18 minutes ago, Tholozor said:

Try opening the AAR door, this will depressurize the external tanks.

Well what the heck. I guess it wasn't a bug. I looked all over in the manual but this is all I found on page 65, I guess I never added 2 and 2 together as it wasn't mentioned in the rearm and refueling page specifically. Thanks a lot man, I appreciate you! NOT A BUG. Operator error!

[RogueSpecterGaming]

1 hour ago, Pribs86 said:

I'll do the best I can to describe this since I don't have any screenshots, video or data. I can only speak for the center tank because that's all I've used. In the F/A-18C, you can take off, burn the center drop tank, land with it still attached, rearm and refuel and it will put a full, fresh, tank on the A/C so you have full fuel when you take off again. If you do this exact same procedure in the F-16C you will NOT get a fresh center tank it will be empty. You either have to remove the tank in the rearm and refuel menu then add it again in the rearm and refuel menu (so you have to rearm and refuel twice every time) -OR- you MUST jettison the tank in flight. It will NOT give you a fresh, full, tank when you rearm and refuel with it attached from the previous flight even though the rearm and refuel page shows a center fuel tank attached. It will be empty. I have tested this many times and it's like clock work. 100% every single time. Like I said I have not tested this with the wing tanks though.

 

Thanks!

Do note, that when using wing tanks you need to be under 4000lbs of fuel to refuel those. Best practice is to land with 1200 to 1800lbs of fuel to ensure they refuel all the way. 

[skywalker22]

2 hours ago, RogueSpecterGaming said:

Do note, that when using wing tanks you need to be under 4000lbs of fuel to refuel those. Best practice is to land with 1200 to 1800lbs of fuel to ensure they refuel all the way. 

If I recall, the min left fuel in tank in 1400 lbs to be able to refuel to max possible (quantity depends on number of external tanks). If you have lets say 1500 lbs left, you will be missing 100 lbs of fuel after refueling.

[falconzx]

or... enable GND Jettison Switch, then Jettison on ground the empty tank before the crew put a new one (in this way you are manually simulate by yourself the removal of the empty one)

Edited August 4 by falconzx

[RogueSpecterGaming]

1 hour ago, falconzx said:

or... enable GND Jettison Switch, then Jettison on ground the empty tank before the crew put a new one (in this way you are manually simulate by yourself the removal of the empty one)

There is literally no need to do that. And irl we wouldnt remove tanks to put on new ones because the new ones would still have to be filled. We dont ever load full fuel tanks. So that doesnt simulate anything. It also sounds like OP is trying not to jettison anything. And some servers have warehouse systems enabled so if you do that, and there is a limited number of fuel tanks, then you eat into the number of tanks available screwing other people over.

[skywalker22]

@RogueSpecterGaming I'm wondering, and since you know from 1st hand how this goes IRL, how othen do they jettison external fuel tanks, if ever? Specially now days when there is practically no dog fights any more.

[RogueSpecterGaming]

13 minutes ago, skywalker22 said:

@RogueSpecterGaming I'm wondering, and since you know from 1st hand how this goes IRL, how othen do they jettison external fuel tanks, if ever? Specially now days when there is practically no dog fights any more.

Extremely rare. Cant even remember the last time I heard about a jet doing it with fuel tanks. I've seen more accidental jettisons of TERs than with fuel tanks on purpose. Even during emergencies it is pretty rare. Usually has to be a very dire situation like theyre too far out to glide that long with tanks on. Lots of factors have to come together, outside of combat, for jettisons to happen. 

[Pribs86]

Thank you everyone for all of your input. I greatly appreciate it! I couldn't figure it out for the life of me haha

[Gilligan]

I had always assumed it was just a DCS-ism and done Ground Jettison to refuel them. Will try opening the fuel door next time. Thanks for that. 

[Pribs86]

Idk, it's still kinda wonky. With an open fuel door and center tank only still, it sometimes it fills the tank entirely (9,000lbs-ish total), other times it only fills it a portion (7,800lbs-ish total). 7,200 is full fuel without external tanks. I have a trackfile, but it's too large and I can't upload anything over 1.64MB for some reason. Anyone know how I can attach this track file to actually be show what's happening? Thank you in advance!

[Mapi]

vor 25 Minuten schrieb Pribs86:

Idk, it's still kinda wonky. With an open fuel door and center tank only still, it sometimes it fills the tank entirely (9,000lbs-ish total), other times it only fills it a portion (7,800lbs-ish total). 7,200 is full fuel without external tanks. I have a trackfile, but it's too large and I can't upload anything over 1.64MB for some reason. Anyone know how I can attach this track file to actually be show what's happening? Thank you in advance!

Same here:

rearmed: Center T emty.

Open the Door:

2. call: Center emty! LOL

I often drop all the <profanity>, so rearm ist faster.

You can call it: cheat

I call it: bad code

... we have 2025

 

 

Edited yesterday at 02:28 PM by Mapi

[RogueSpecterGaming]

39 minutes ago, Pribs86 said:

Idk, it's still kinda wonky. With an open fuel door and center tank only still, it sometimes it fills the tank entirely (9,000lbs-ish total), other times it only fills it a portion (7,800lbs-ish total). 7,200 is full fuel without external tanks. I have a trackfile, but it's too large and I can't upload anything over 1.64MB for some reason. Anyone know how I can attach this track file to actually be show what's happening? Thank you in advance!

@Mapi

For both of you.

Were you under 4000lbs? The goal fuel to be at to get topped off is around 1200-1500lbs. Even with wing tanks. Best practice is to open the refuel door the minute you land to depressurize the tanks so they can take fuel. 

 

Isnt it bad code. If you arent low enough in fuel then the amount of fuel you receive will vary. Just like in real life. This area of the F16 is actually modelled pretty well. 

[Pribs86]

3 hours ago, RogueSpecterGaming said:

@Mapi

For both of you.

Were you under 4000lbs? The goal fuel to be at to get topped off is around 1200-1500lbs. Even with wing tanks. Best practice is to open the refuel door the minute you land to depressurize the tanks so they can take fuel. 

 

Isnt it bad code. If you arent low enough in fuel then the amount of fuel you receive will vary. Just like in real life. This area of the F16 is actually modelled pretty well. 

I just did it a second ago. Landed with center tank attached. 6,800lbs of fuel left yet. Opened AR door, called for refuel, center tank still attached, 7,300lbs of fuel. Unless it takes more time to depressurize the tank. I do it right before rearming. Unless it takes more time then I will start opening the AR door as soon as I land and start taxiing to a parking spot. Let me give that a try quick.

[razo+r]

3 hours ago, Pribs86 said:

 I have a trackfile, but it's too large and I can't upload anything over 1.64MB for some reason. Anyone know how I can attach this track file to actually be show what's happening? Thank you in advance!

You have to go to your profile and then attachments and delete unwanted/unused attachments to free some space again.

[Pribs86]

31 minutes ago, Pribs86 said:

I just did it a second ago. Landed with center tank attached. 6,800lbs of fuel left yet. Opened AR door, called for refuel, center tank still attached, 7,300lbs of fuel. Unless it takes more time to depressurize the tank. I do it right before rearming. Unless it takes more time then I will start opening the AR door as soon as I land and start taxiing to a parking spot. Let me give that a try quick.

Just tried it again - landed with 4,500 lbs of fuel, opened the AR door immediately after landing, taxied to parking spot, rearm and refuel with center tank connected still, 8,600lbs of fuel total. Still not completely full for some reason. I'm on the Falklands, if that matters.

25 minutes ago, razo+r said:

You have to go to your profile and then attachments and delete unwanted/unused attachments to free some space again.

ahhh thank you so much, appreciate the help. If I remove them, will it remove them from the posts/comments I've already made on the threads? (im not sure what its called, forgive my ignorance)

Edited yesterday at 06:22 PM by Pribs86

[Pribs86]

Oh man, this might work. I had to zip the file so let me know if anyone can see it or not. I will try to get a smaller flight/track file later on if I am able to.

4YA_SA_PVE_V2.106[03_MAR_BKN]-20250812-081202.7z

Edited yesterday at 06:32 PM by Pribs86

[razo+r]

2 hours ago, Pribs86 said:

ahhh thank you so much, appreciate the help. If I remove them, will it remove them from the posts/comments I've already made on the threads? (im not sure what its called, forgive my ignorance)

Yes, it will remove the attachments you deleted from the posts in which they were.

As an alternative, you can also use external hosting websites. Imgur for pictures, Dropbox for other files, as an example.

[Pribs86]

11 minutes ago, razo+r said:

Yes, it will remove the attachments you deleted from the posts in which they were.

As an alternative, you can also use external hosting websites. Imgur for pictures, Dropbox for other files, as an example.

Gotcha. Thank you. Weird how it deletes them Because what if someone else ever needs the file, but I guess it frees up space.

[RogueSpecterGaming]

4 hours ago, Pribs86 said:

Just tried it again - landed with 4,500 lbs of fuel, opened the AR door immediately after landing, taxied to parking spot, rearm and refuel with center tank connected still, 8,600lbs of fuel total. Still not completely full for some reason. I'm on the Falklands, if that matters.

ahhh thank you so much, appreciate the help. If I remove them, will it remove them from the posts/comments I've already made on the threads? (im not sure what its called, forgive my ignorance)

Did you even read what I said man? UNDER 4000lbs. Not 6800 not 4500. UNDER 4000lbs. You really should be AIMING for 1200-1500lbs. If you are landing with that much fuel then you dont need tanks anyways. Try again please. And actually have a long flight that brings you under 4000lbs or just stay in burner. Again, 1200-1500 is preferred if you want to get full fuel. 

 

But you did just prove that it does vary depending on how much fuel you have so there is that lol. But just read what i wrote.

[Pribs86]

15 hours ago, RogueSpecterGaming said:

Did you even read what I said man? UNDER 4000lbs. Not 6800 not 4500. UNDER 4000lbs. You really should be AIMING for 1200-1500lbs. If you are landing with that much fuel then you dont need tanks anyways. Try again please. And actually have a long flight that brings you under 4000lbs or just stay in burner. Again, 1200-1500 is preferred if you want to get full fuel. 

 

But you did just prove that it does vary depending on how much fuel you have so there is that lol. But just read what i wrote.

I read and understood what you said, so you don't have to patronize me. If this interaction is upsetting you then you don't have to respond. You can ignore this completely and go about your day doing other things. I have a issue that I would like to learn more about it all.

 

So my question to all of this is WHY. WHY can you only get FULL fuel if you are under 4,000lbs, WHY?

 

What if a pilot IRL takes a tank thinking he or she will need it but learns while flying that it isn't needed/required? What if he/she can't jettison the tank (civilian population or malfunction)? What if they don't (or aren't able to) burn ALL of the fuel? If a pilot lands in real life with 4,100lbs (h3ll, let's call it 4,001lbs even) and has to rearm and refuel quickly to get back on mission (they don't have time to ground jettison the center tank and add a new one), in real life again, does the crew tell them "f@ck you, you didn't land with under 4,000lbs so we aren't going to fill that center tank completely or at all, you get your ass back up there" even though the next flight might require 8,500lbs of fuel (make up number, whatever). Is there a limitation with the tanks mechanically so to speak. Is this an actual real life restriction/constraint/limitation with the external fuel tanks (seems funny to me if it is)?

 

I just want to know WHY this is happening. Was designed that way in the game intentionally or on accident? Is it was a bug? Is that how they do it IRL (maybe they do tell the pilot f@ck you, who knows)? I just want to know WHY.

 

By the way it does work when you are under 4,000lbs and you do get topped off.... but WHY?

[Nedum]

17 hours ago, RogueSpecterGaming said:

Did you even read what I said man? UNDER 4000lbs. Not 6800 not 4500. UNDER 4000lbs. You really should be AIMING for 1200-1500lbs. If you are landing with that much fuel then you dont need tanks anyways. Try again please. And actually have a long flight that brings you under 4000lbs or just stay in burner. Again, 1200-1500 is preferred if you want to get full fuel. 

 

But you did just prove that it does vary depending on how much fuel you have so there is that lol. But just read what i wrote.

Whenever I see your very rude manner of communication, I find it extremely difficult to believe that you actually work on an F16 yourself. 
Apart from that, it would be important to know which Army regulation prohibits refueling an external tank unless it contains less than 4,000 pounds of fuel? Why less the 4,000 pounds of fuel and not 3,500 or 4,500 or empty?
There should be reason for it! What is it?
What happens if a pilot lands with more than 4,000 pounds of fuel in the center tank, the aircraft is rearmed, and he basically needs a full center tank to complete his mission?
It may well be as you describe here, but what are the reasons for this, and what measures are or must be taken to ensure that the center tank can be refilled to capacity when it contains 4,100 pounds of fuel instead of 3,999 pounds?
Please share your knowledge with us.
An essential part of this hobby is knowing why and how to do things so that they work in the end.
When you work on the F16, you will be told the reason. At least that's how it is in the Deutsche Luftwaffe. Everyone is told why certain things have to be done in a particular way.
I firmly believe there is no difference in the US armed forces. It would be nice if you could help us to understand what are the reasons for all of this.

Thank you!

Edited 6 hours ago by Nedum

[Tholozor]

AFAIK (didn't work on F-16s, but have worked in aviation refueling), in order for fuel to reach the external tanks from the single-point refueling receptacle, the fuel must first flow through the internal tanks (I'm not sure specifically which tanks in which order without the fuel system diagram in front if me).  Since the internal tank pressure is only reduced as opposed to completely depressureized, it takes a bit of force to push the fluid through those tanks so fuel can flow to the externals.

The other half of the problem is that the fuel slider in the rearming menu only cares about internal fuel level. So once the internal tanks are completely filled, the ground crew will stop fuel flow, even if the externals are only partially filled. This is a long-standing DCS limitation, as realistically you'd probably either be able to keep fuel pressure and permit flow to the externals, or just fuel the external tanks manually via the fill caps with an over-wing nozzle. ED has mentioned in the past about the possibility of having fuel sliders for external tanks in addition to internal.

The reason people have made the suggestion to be under a specific amount of fuel is to ensure that there's enough time for fuel to flow to the external tanks before the internals are filled, cutting off fuel flow. While this is a more "rule-of-thumb" method to ensure external tanks are refilled, the best guarantee is to have the ground crew remove and replace the external tanks (jettisoning the tanks not necessarily required, depending on your situation).

Edited 4 hours ago by Tholozor