Refueling

Hey everyone,

After all this time I've finally started to practice aerial refueling.

I'm just curious about one thing. When I initially call into the tanker, he responds and tells me to proceed to Pre-contact. So far so good, the tanker seems to even slow down to around 175 kts for me to catch up.

After I catch up and get in position, I tell the tanker I'm ready for pre-contact, the tanker responds "clear contact" but then immediately speeds up to 185 kts or so.

My question is: Is this normal behavior? Or could it be something in the mission editor that I messed up?

Thank you!

What speed does the mission editor say the tanker should be flying?

I personally have never been able to get Air refueling to work properly. Whenever i get close to it and the tanker says "cleared contact", the boom never drops, and he sppeds up, then goes and lands

What speed does the mission editor say the tanker should be flying?

Well, in the mission editor I have all the waypoints set up at 270 kts. On waypoint 3 however, I have a Race-Track orbit set up with a speed of 232 kts at 22,000 feet.

I have two separate speeds for the waypoints and for the orbit. Could the AI be grabbing one speed when it's waiting for me and another after pre-contact?

Also, the speeds I have set up are vastly different than the 175 kts and 185 knts I'm seeing on my A-10C as described in my OP.

It's probably stalling at that altitude... I'd put it to 290 across the board and see what happens.

I'm not sure of the formula- cant remember it but as an example I think the stock speed of 270 translates to 195 or so at 15000. 232 @ 22000 is going to be tres low.

It's probably stalling at that altitude... I'd put it to 290 across the board and see what happens.

 

I'm not sure of the formula- cant remember it but as an example I think the stock speed of 270 translates to 195 or so at 15000. 232 @ 22000 is going to be tres low.

You know, this is silly but, I always just assumed it was indicated airspeed instead of ground speed for the mission editor.

That makes a lot of sense. I'll try 290 kts for the waypoints AND the orbit.

Thanks for the suggestion ENO. :thumbup:

Once you get it working then you can play with the speeds through the waypoints. Also don't be afraid to use "switch waypoint" to start off so you get long straight runs to practice with. Can explain in more detail if needed.

Once you get it working then you can play with the speeds through the waypoints. Also don't be afraid to use "switch waypoint" to start off so you get long straight runs to practice with. Can explain in more detail if needed.

I made the way point speed and orbit speed the same, and that seemed to fix the tanker speeding up after pre-contact. So thank you for that suggestion!

I set it at 270 kts at 18,000 which seems to be around 210 IAS on the A-10C.

Do you or anyone else have a speed/altitude that you like to use as a "standard" refueling set-up?

Also, I'm not sure what you meant by the "switch waypoint" comment. I don't see it anywhere in the orbit settings for the tanker.

Thanks for your help so far though! ;)

Picked this up on the forums a while ago. Think it was Stuka's. As you can see the A-10 is nearly the slowest of the lot at 220 knots. :P

nice chart, now we need altitude for americans and russians planes and speed too for the russians.

Kasper- switch waypoint is a "perform command" option in waypoint options. Lets say you just want to practice hooking up- constant speed and heading for a longer orbit than the race track affords.

You can set two waypoints a long ways apart... (Technically you can just set one waypoint if you air start the tanker because the starting point is a waypoint) 50+ miles or however long and if you want it to "orbit" in that track you just give a switch waypoint command at waypoint 2. It'll ask you which waypoint and you say you want to switch it to the last waypoint... So the aircraft will fly back to the last waypoint at which point it will follow those commands ie: fly to waypoint 2.

It'll do this until it is bingo fuel.

So it's like a race track orbit but you get to pick the size of the legs. It's good for gradually easing in to the tighter orbits.

Kasper- switch waypoint is a "perform command" option in waypoint options. Lets say you just want to practice hooking up- constant speed and heading for a longer orbit than the race track affords.

 

You can set two waypoints a long ways apart... (Technically you can just set one waypoint if you air start the tanker because the starting point is a waypoint) 50+ miles or however long and if you want it to "orbit" in that track you just give a switch waypoint command at waypoint 2. It'll ask you which waypoint and you say you want to switch it to the last waypoint... So the aircraft will fly back to the last waypoint at which point it will follow those commands ie: fly to waypoint 2.

 

It'll do this until it is bingo fuel.

 

So it's like a race track orbit but you get to pick the size of the legs. It's good for gradually easing in to the tighter orbits.

Very cool! Although, correct me if I'm wrong , but doesn't the "race-track" orbit do this just on it's own? In my picture posted earlier, I have waypoint 3 calling for the orbit action. I assumed that the race-track orbit would travel between waypoint 3 and 4. So if I happen to set waypoint 4 50 miles out, wouldn't the orbit encompass that?

Picked this... :P

Stuff like this should be in the in-game Encyclopedia. I might just go edit that chart into my encyclopedia.

Very cool! Although, correct me if I'm wrong , but doesn't the "race-track" orbit do this just on it's own? In my picture posted earlier, I have waypoint 3 calling for the orbit action. I assumed that the race-track orbit would travel between waypoint 3 and 4. So if I happen to set waypoint 4 50 miles out, wouldn't the orbit encompass that?

Yes, I think you can control the length of race track orbit by spacing waypoints.

Picked this up on the forums a while ago. Think it was Stuka's. As you can see the A-10 is nearly the slowest of the lot at 220 knots. :P

How do you get an AI controlled aircraft to react differently for A-10s or F-15s? I'm assuming you can't even do this. So maybe the answer would be to have two separate tankers, one for slow aircraft (220 kts) and one for Fast movers (315 kts)

Well I'll have learned something if you can't max out the size of the orbit. Thought it was limited to 30 miles or something...

I don't think it orbits between 2 waypoints- ill have to go back and look at it but seems to me I decided not to use it for that reason... But it's been awhile maybe I had it messed up before.

Back to the ol drawing board.

I don't think it orbits between 2 waypoints- ill have to go back and look at it but seems to me I decided not to use it for that reason... But it's been awhile maybe I had it messed up before.

Be sure to post your findings! :)

VJS161_Fire recently said in an ME tutorial for building AAR missions (German only, sorry) that the race-track waypoint and the following waypoint act as the constraint for the orbit. But that's really all I ever heard about it, so if you find out whether that's correct, it would be good to know. :thumbup:

Well I'll have learned something if you can't max out the size of the orbit. Thought it was limited to 30 miles or something...

 

I don't think it orbits between 2 waypoints- ill have to go back and look at it but seems to me I decided not to use it for that reason... But it's been awhile maybe I had it messed up before.

 

Back to the ol drawing board.

I got curious too so I put a F-15 to orbit between Anapa and Min Vody, it flew the whole route until out of fuel.

Thanks guys- good to know.

nice chart, now we need altitude for americans and russians planes and speed too for the russians.

I think anything between 14-18 000 would do. It will vary by aircraft, but I think the best performance envelope for the A-10 refueling at 220 is somewhere between Angels 14-16.

Also, peeps should be aware that this is IAS not GS or TAS. The speed which is set in the Mission Editor is, I think, KTAS so depending on the altitude and outside air temperature a different KTAS will result in the required 220 KIAS. You can either google a CAS to TAS calculator (CAS is just IAS calibrated for instrument error) and get a figure or just ballpark it, launch the mission, and tweak the number til the tanker is doing about 220 knots indicated.

How do you get an AI controlled aircraft to react differently for A-10s or F-15s? I'm assuming you can't even do this. So maybe the answer would be to have two separate tankers, one for slow aircraft (220 kts) and one for Fast movers (315 kts)

Basically yes. In real life every rejoin is a well planned, scripted affair. You get a slot and meet the tanker on its track and the tanker knows your flight of your aircraft type is coming so they're going to go to an agreed upon alt and speed that will suit your aircraft's needs.

Clearly this is beyond the capability of current DCS AI so you either make 2 tankers or you just split the difference and find a compromise speed that'll do fine for both types. In the future I hope ED makes tanking a more scripted affair because as it is its pretty unrealistic.

I would love to have the ability to tell my wing to form on the tanker and not just me, for the refueling string to include me and not have me hand off my wing to it, to have the ability to request from the boom operator a set amount of fuel which he'll cut me off at once I have it, and to be able to tell my wing to request the same amount as well. So many more things to want.

A good calculation to determine tanker TAS (IAS always 220 kts) on various altitudes are:

(220 * 0,018 * X) + 220 = TAS

X: altitude, ex 20 for 20.000´ MSL.

This way, you can always calculate what the best tanker orbit speed is for various altitudes for a Warthog refuel.

So for the A-10: 15 000 ft, 220 IAS (or M.48).

From the NATO document ATP-56, Annex ZE (you can find that on the RAF website)

Hope it helps :)

Now thats a way better picture than mine. :P

Clearly this is beyond the capability of current DCS AI so you either make 2 tankers or you just split the difference and find a compromise speed that'll do fine for both types. In the future I hope ED makes tanking a more scripted affair because as it is its pretty unrealistic.

What you also can do, is set two different patterns for the tanker and make him switch between the two using the Switch waypoint triggered action.

What you also can do, is set two different patterns for the tanker and make him switch between the two using the Switch waypoint triggered action.

Doesn't this still mean that you can't control when he's on the fast and the slow track, or is there some command to remotely send him into the correct orbit?

You can use the Radio menu F10 to direct the tanker into the pattern you like.

Other ways would be detecting when an aircraft is approaching and directing the tanker into a specific track depending on the aircraft type, but this is way more complicated and requires .lua Scripting.

Here's a tutorial mission that I made some time ago, I hope it still works with 1.2.7.

The part you can't really do is a realistic rendez-vous.

AAR Tracks tutorial.miz