Air to air refueling...

That's not wrong, but it is only half of the truth. What I miss in this answer and in DCS is the stabilising part of the connection itself. There a procedures to tow a fighter back to safe airspace. You can't do this without a connection that is more than it is now in DCS.

That's what I mean by "more abstracted". Would it be nice if it was 100% like in real life? Of course, but we are not there yet and I simply described the way it's working *in DCS* right now.

Imho it is not abstract caus it is not real life, it is abstract caus it is not realistically simulated in DCS yet.

See above

There would be so much benefit if it was done realistically. And why shouldn't it be done like IRL? AAR and carrier landings are two major challenges with flight sims. Those should not be artificially easier than IRL but certainly they should not be harder just because there are important aspects missing that can be implemented if there was a will to do that.

Now you are projecting - I'm pretty sure there is a will to do it as realistically as possible (see adding wake vortices a while back), but there is also only so much capacity to actually bring all these things to the sim. You see the whining that's happening already due to some entitlement-issue plagued users shedding a tear about the "abandoned F-18", so I simply figure this is rather low on the priorities list.

We have a working AAR implementation both for boom and for basket refueling, that works decently realistic.

 

Now you are projecting - I'm pretty sure there is a will to do it as realistically as possible (see adding wake vortices a while back), but there is also only so much capacity to actually bring all these things to the sim. You see the whining that's happening already due to some entitlement-issue plagued users shedding a tear about the "abandoned F-18", so I simply figure this is rather low on the priorities list.

You may be right. I come to this assumption because I haven't found any statement about the missing realism of DCS's boom contact from any dev yet. That's all. I'm of the patient fraction (I use stable version :smilewink: ). So time is not the problem for me. I just hope for a statement that devs care about the boom refueling system in the future. It seemd to me, that the Viper is a good reason to start/publish(?) the plans for that.

 

We have a working AAR implementation both for boom and for basket refueling, that works decently realistic.

I agree til the "," :smilewink:

I just hope for a statement that devs care about the boom refueling system in the future. It seemd to me, that the Viper is a good reason to start/publish(?) the plans for that.

They stated a few times that we will see realistic basket physics in the future, but I'm too lazy to search for that now. I'm betting that will extend to boom refuelling, too. :)

I agree til the "," :smilewink:

I think we may disagree on the "decently" :D

:D :thumbup:

That's not wrong, but it is only half of the truth. What I miss in this answer and in DCS is the stabilising part of the connection itself. There a procedures to tow a fighter back to safe airspace. You can't do this without a connection that is more than it is now in DCS.

 

 

Imho it is not abstract caus it is not real life, it is abstract caus it is not realistically simulated in DCS yet.

 

 

There would be so much benefit if it was done realistically. And why shouldn't it be done like IRL? AAR and carrier landings are two major challenges with flight sims. Those should not be artificially easier than IRL but certainly they should not be harder just because there are important aspects missing that can be implemented if there was a will to do that.

Yup. A good example of a connection would be applying a force vector along the boom axis from the plane. I.e. up and forward. This plane motion should be restricted or redistributed to the tanker somehow. Side to side oscillations should likely be damped a bit as well. The only thing that shouldn't have too much of an effect should be a reducing speed/descending maneuver, but even in this case there should be somewhat of a coupling force required to unplug.

Right now you are 100% just station keeping in some magic fuel box which doesn't "feel" right to me. I find it much easier to tank with the basket tankers f18/14/su33 etc. And while it might be the same thing, keep the plane in the fueling box, it somehow seems different, maybe different visual cueing? IDK...

Right now you are 100% just station keeping in some magic fuel box which doesn't "feel" right to me. I find it much easier to tank with the basket tankers f18/14/su33 etc. And while it might be the same thing, keep the plane in the fueling box, it somehow seems different, maybe different visual cueing? IDK...

Exactly!

It might be the case that the basket zone is a lot larger than the boom zone. Especially the forward and aft range. But that is just an unconfirmed feeling.

However my dream is about a future where boom refuelling is easier than basket AAR. Achieved by a realistic contact.

While I don't have a problem with AAR'ing either way, boom refueling already is a ton easier, for me, subjectively. I had it nailed earlier than the basket, because just like in real life it is basically formation flying and holding first and foremost.

Since there is no way that a fighter can be towed or stabilized by a single percent of any extent, the DCS implementation of boom refuelling is certainly not like it is in real life. This is not an opinion. It is logic.

And I hope realism where it helps many struggling users is more important than: I don't want it caus I don't need it. Still no offence with your opinion but would it really hurt if they implement a more realistic contact with the boom?

Yup. A good example of a connection would be applying a force vector along the boom axis from the plane. I.e. up and forward. This plane motion should be restricted or redistributed to the tanker somehow. Side to side oscillations should likely be damped a bit as well. The only thing that shouldn't have too much of an effect should be a reducing speed/descending maneuver, but even in this case there should be somewhat of a coupling force required to unplug.

But thats not how it works in real life. Forces of the nature you are describing would damage equipment. The forces applied along the axis of the boom you are describing are minimal because the boom telescopes freely in and out while in contact. Surge boots and valves ensure hydraulic forces inside the fuel tube are minimized. In the KC-135 while in contact the boom operator manually aligns the boom with the receptacle. The best indication the boom is properly aligned is when it’s “Dancing”. When the boom is Wiggling juuuuust slightly right where the inner and outer tube meet there is no stress on the connection. On the KC-10 the Boom Computer flies the boom to maintain less than 500lbs of pressure in any one direction.

And lateral boom position has far more effect than you believe. Not because the receiver is applying force...because that long skinny boom actually has quite a bit of surface area and it’s attached to the tail of the airplane right under the rudder. During CFIC we would fly the departure out of castle with the boom. By flying the boom out to the right or left limit we would cause the airplane to roll and turn the direction we wanted.

And there is no force required to uncouple. When the boom goes in the receptacle, latch toggles hydraulically capture the boom. On disconnect, the toggles retract and the boom floats out of the receptacle if boom alignment is good. If the toggles don’t retract...there is a procedure. But normally no force.

that's verry interesting Sierra99. Thank you for the clarification.

But how does towing a fighter work with close to no force on the boom? (Did I miss something? EDIT: I reread your post and I now got it: "latch toggles" do the job, right?) Is there a system that holds connection if you have to, so the connection stands a drag that is caused by too less thottle of the fighter?

I was verry excited while reading your post about dropping a F-16 like a tank :thumbup: . It seemed to me, that there is quite a bit force, that a boom can stand in the extending direction. I mean, you havn't been fired from the airforce for risking government material, have you? (just kidding)

I appreciate your posts. every single one, and look forward to understand how AAR with a boom IRL differs from DCS implementation.

a) What is your opinion with DCS boom refueling?

b) Do we need a better implemention?

c) If yes, do we need a damage model for uncorrect boom-receiver-interaction?

(I'm sorry, I have 100 questions but I don't wanna waste too much of your time.) :)

And I hope realism where it helps many struggling users is more important than: I don't want it caus I don't need it. Still no offence with your opinion but would it really hurt if they implement a more realistic contact with the boom?

Like I said: I am all for realistic options, I just don't feel that what we have is entirely unrealistic. As Sierra99 (being an SME better listen to him and not me, anyways :) ) said: there's little to no forces involved, with good reason.

And because of that I still think what we we have is decently realistic. He may chime in more on that :)

Yes, I'm completely with you. Info from a real boom operator is of much more value than any speculation. I understood Sierra's last post quite like you. If there is/should be close to no force to the boom I want to know if it is enough to help the receiving pilot while holding position. And if so, I strongly recommend to get that into DCS.

I once was overwhelmed by the challenge of AAR. And after lots and lots of practice and buying a new stick :smilewink: I'm now able to get my fuel quite well and concider AAR super fun.

But I'm a little bit... disturbed by the thought that a real contact should have been helpful and might have been able to cut my training time to half of it.

I'm still driven by the dream that closing a tanker with a DCS Viper brings more joy than "fear". Not only to me but to all of those that complain about AAR in so many threads.

If ED has AAR covered realistically enough and there is evidence for it, I'll give up my dream. But if it ain't so, I won't stop til I see a realistic contact with a boom. :joystick:

But how does towing a fighter work with close to no force on the boom? (Did I miss something? EDIT: I reread your post and I now got it: "latch toggles" do the job, right?) Is there a system that holds connection if you have to, so the connection stands a drag that is caused by too less throttle of the fighter?

The envelope is defined by automatic limit switches connected to the boom; the envelope permits a limited amount of fore and aft movement and some freedom of maneuver in the pitching, rolling and yawing planes. The envelope limits are set well within the mechanical limitations of the boom; therefore, provided the envelope limits are not exceeded too rapidly, disconnect will occur before the boom is damaged. The freedom of maneuver in boom elevation is reduced for some receiver aircraft because of their receptacle characteristics. For example F-15s are limited in Left azimuth because as the receiver moves Left the Fuel Tube and Boom get quite close to the Canopy. I ">THINK< The F-16 and A-10 were the only fighters that could use the entier 20-40 U/D 10-10 L/R of the -13 envelope. The rest had some sort of limitation either UP (NO higher than 25) or L/R as the F-15.

I was very excited while reading your post about dropping a F-16 like a tank :thumbup: . It seemed to me, that there is quite a bit force, that a boom can stand in the extending direction. I mean, you havn't been fired from the airforce for risking government material, have you? (just kidding)

We only did that occasionally :smilewink:

I appreciate your posts. every single one, and look forward to understand how AAR with a boom IRL differs from DCS implementation.

a) What is your opinion with DCS boom refueling?

The biggest limitation of DCS AAR is the Boom Operator doesn't "learn". In 1987 I cautious with every contact...the more stable the receiver was...the better I felt about my abilities. Over time that changed I learned the receiver didn't need to be rock steady in the middle of the box to get a contact...I got more confident in my abilities which made it easier for BOTh of us. I wasn't afraid of bashing the receiver...he didn't have to work so hard waiting foor me to plug him.

b) Do we need a better implementation?

Everything could be "better"...the question is what do you want ED putting their resources in to? For me, AAR is a diversion. I don't "Need it" to fly the missions I fly.

Here's the thing folks need to understand. AAR allows aircraft to loiter for hours and not do anything...My avatar pic was taken over Iraq during OIF. We refueled a Pair of A-10s 5 times over 3 hours in the dead of night while the folks on the ground sorted out exactly what targets they wanted hit. Finally they came to get gas and told us they wouldn't be back. The went and hit the targets and went home. We don't do missions like that in DCS...Most people would call them boring...but it's real life. We use AAR to establish and most importantly MAINTAIN a presence over a country. In DCS we wanna bomb stuff...which is fine...but we dont really need AAR to do it.

NOW that being said I'd like to see a better Carrier AAR asset. There is a big difference between maintaining a presence for hours and "I just boltered 4 times and now I'm outta gas". Carrier folks could use a better AAR platform because operationally its much more critical to them on every mission.

c) If yes, do we need a damage model for uncorrect boom-receiver-interaction?

Again where do you want the resources. In 22 years I only saw real 'damage' to a receiver once. (I flew home with parts of HIS airplane still attached to mine...During a SAC ORI...And I got an award...Go figure...Loooooong story.) Most of the time poor interactions result in scratched paint and a "broken / unusable system"...but no real visible damage.

Thanks for your real-life insight, that is highly interesting! That I see things similar with regards to DCS is just the icing on the cake :D

But thats not how it works in real life. Forces of the nature you are describing would damage equipment. The forces applied along the axis of the boom you are describing are minimal because the boom telescopes freely in and out while in contact. Surge boots and valves ensure hydraulic forces inside the fuel tube are minimized. In the KC-135 while in contact the boom operator manually aligns the boom with the receptacle. The best indication the boom is properly aligned is when it’s “Dancing”. When the boom is Wiggling juuuuust slightly right where the inner and outer tube meet there is no stress on the connection. On the KC-10 the Boom Computer flies the boom to maintain less than 500lbs of pressure in any one direction.

 

And lateral boom position has far more effect than you believe. Not because the receiver is applying force...because that long skinny boom actually has quite a bit of surface area and it’s attached to the tail of the airplane right under the rudder. During CFIC we would fly the departure out of castle with the boom. By flying the boom out to the right or left limit we would cause the airplane to roll and turn the direction we wanted.

 

And there is no force required to uncouple. When the boom goes in the receptacle, latch toggles hydraulically capture the boom. On disconnect, the toggles retract and the boom floats out of the receptacle if boom alignment is good. If the toggles don’t retract...there is a procedure. But normally no force.

Ah good, someone who knows what they are talking about. Thanks for the correction. I didn't realize the thing telescoped.

On the lateral boom note, if I'm reading that the boom should stabilize any sort of lateral movment? And also when coupled I assume the plane should be harder to roll or is there alot of play in that too?

yeah, thanks Sierra99 for your answers and insights.

Those keep my dream alive. But you are right, when you mention the resources of devs and time. I will wait, hope, and may be.. see :thumbup:

Ah good, someone who knows what they are talking about. Thanks for the correction. I didn't realize the thing telescoped.

 

On the lateral boom note, if I'm reading that the boom should stabilize any sort of lateral movment? And also when coupled I assume the plane should be harder to roll or is there alot of play in that too?

The boom flies in every sense of the word. If you unlatch the boom on the ground...it will promptly fall to the pavement because the flight control surfaces of the boom (ruddervators for the -135 and elevators and Rudders for the KC-10) don’t have air flowing over them.

As such the boos are trimmed to trail at 30* and 0 Roll +- 3 degrees (?) if you fly the boom to the left or Right and let go...it will return to center.

As far as roll...no the receiver can do what he want right up to the point it starts bending and breaking stuff.

Flying in formation behind a drogue is one thing. Flying underneath the KDC-10 or KC-135 is another! Can't wait to try that out :)

As far as roll...no the receiver can do what he want right up to the point it starts bending and breaking stuff.

Wouldn't there be some sort of feedback/stabilization though? I guess I'm thinking about it like a U-jointy/floaty-shafty thing (sorry if that was too technical), I get that it can float around but the plan-boom-plane seems like it should be a sort of a linkage and you would have some physical feedback if you went too far before you broke things.

Sensibly, I suppose that the boom control surfaces wouldn't need to be that large, as guiding a disconnected boom would be relatively easy and once connected to multiple tonnes of aircraft, they would be easily overriden by the pilot of the receiver?

Flying in formation behind a drogue is one thing. Flying underneath the KDC-10 or KC-135 is another! Can't wait to try that out :)

Try it with the F15

Try it with the F15

Well, I could if I owned it :music_whistling: but I only have the high fidelity modules.

But with the F16 around the corner I don't have to wait much longer :joystick:

Wouldn't there be some sort of feedback/stabilization though? I guess I'm thinking about it like a U-jointy/floaty-shafty thing (sorry if that was too technical), I get that it can float around but the plan-boom-plane seems like it should be a sort of a linkage and you would have some physical feedback if you went too far before you broke things.

The boom will automatically disconnect when it gets near to limits, ideally before it breaks stuff. But the pilot of the jet still has to do his bit to hold position.

The boom will automatically disconnect when it gets near to limits, ideally before it breaks stuff. But the pilot of the jet still has to do his bit to hold position.

Roger that. This "bit" is what I am here for to learn. At the moment the pilot has to do it all. I said it before and Harlikwin's description of a "magic zone" where fuel is flowing hits exactly what I feel while being connected: nothing.

Real boom operator said before something that lets me conclude: "nothing" is not how it should be according to reality.

So I'm satisfied with every little "bit" that provides a feeling. There is none yet.

Roger that. This "bit" is what I am here for to learn. At the moment the pilot has to do it all. I said it before and Harlikwin's description of a "magic zone" where fuel is flowing hits exactly what I feel while being connected: nothing.

 

 

Real boom operator said before something that lets me conclude: "nothing" is not how it should be according to reality.

 

 

So I'm satisfied with every little "bit" that provides a feeling. There is none yet.

The only thing o can add is IRL the only real "action / reaction" issue during refueling was directly related to the size of the receiver being refueling...but for completely different reasons. Fuel pressure and Bow wave.

With fighters you had to limit how many pumps you used during AR. Fighters are relatively light aircraft...,the fuel tube being free floating would telescope out due to pressure if the fighter wasn't taking the fuel as fast as it was being pumped. So I might make a contact at 12' but when we started passing fuel they'd slide back slowly to 13-14 feet. Enough to get a "fly forward" light on the PDIs. It usually wasn't aggressive event but it was directly related to the hydraulic effect of the fuel flow being somewhat constricted.

With heavies you could run 4 AR Pumps all days and they'd take the fuel without really noticing...but with heavies ya get a different interaction. Bow Wave. The nose of a heavy receiver (C-5 C-17, KC-10 etc) pushes a mass of air along in front of it that interacts with the tail of the tanker. As a C-5 closes to contact the air it's pushing with its nose begins to push UP against the tail of the tanker causing the tanker to want to descend. It also creates a big cushion between the two aircraft the receiver must push through as they close to contact. The same thing happens with fighters but to a lesser extent. They have to push through the tanker wake.