F-15 tips for high altitude against F-16 vipers

[Steelpanther]

Hi!

 

I started flying DCS planes with the FC3 module to test out things first. I mostly played WW2 warbirds planes like in the old IL2 sturmovik games. I'm really liking the F-15 so far because the manuals, cockpit gauges, and HUD symbology is very easy to understand.

I was trying also multiplayer and the enemy side F-16 vipers are really tough opponents when they get up to the altitude >= 40k feet. Apparently the F-16 can afterburn and stay very controllable with droptanks at that altitude. Typically they would be around 1.6 mach patrolling there.

 

I'm not totally sure on the latter point (if they had still droptanks or not, while afterburning) because I don't have F-16 module, but judging from tacview they do stay very fast supersonic, at very high altitudes.

 

1.) radar effectiveness. I feel like I really struggle to find enemy F-16s at anywhere decent ranges on the range-while-search even when searching the correct altitudes (indicated by friendly AWACS). Is there something wrong with the radar in game or is it just operator error? F-16 does seem to get immediate datalink LINK16 updates from the enemy AWACS which probably does improve F-16 situational awareness a lot.

 

2.) Can the eagle take advantage of its higher service ceiling by flying at 60k feet, as opposed to the viper. From what I've read the eagle and viper should have about similar thrust-to-weight ratios, but eagle has higher service ceiling. From the F-15 perspective though the high altitude seems to be very sluggish and slow unless I'm afterburner without droptanks. I suppose the good tactic would be to use the droptanks for quick climb to high altitude, then fly towards combat area with droptanks and at some point jettison them and stay supersonic at altitude. (?)

 

3.) I used to have a problem where I was really slow on the F-15 at afterburner, but I think I managed to narrow it down to DCS World throtle not registering the input all the way up to the max level. This was a bit hard to narrow the problem down because I was still in afterburner in external camera view. I tried to fix the problem by putting a "deadzone" at the upper end of the throttle travel with "saturation X". Can anyone confirm if in the axis curve tuning settings, the black square, does that mean the actual in-game registered throttle level, and the red square seems to indicate the controller input directly? So it appears that saturation X will allow the in-game throttle setting to go all the way up, to compensate for the upper end throttle "deadzone"?

 

4.) can someone provide some reference values for nozzle position gauge, RPM gauge and fuel burn gauge, mach number and altitude, for the max thrust setting for F-15 to verify that the above problem was fixed with the saturation X? (I just have this one throttle and I ordered a new hotas but its still in backlog, probably because of covid delays or something). I discovered the problem by mapping the thrust into my joystick's axis, which is definitely unusable in practice, but it allowed me to discover the problem.

 

[dundun92]

So I can answer 1 and 2

 

For 1, yes the F-15 radar is seriously underperforming (over 50% compared to the original APG-63, nvm the MSIP one we have). Essentially dont expect to detect fighter sized targets past 50-60nm lookup, and 40nm lookdown. (In reality the numbers should be at 90+ for lookdown)

 

For 2, it's your climb profile. I used to have the same issues. Firstly NEVER take the center bag unless you absolutely need the extra range (which isn't the case on PvP). It has more drag than both wing tanks combined. Just take 2 wing tanks and you'll be fine.

Additionally, dont try and accelerate at 40k. That's too high if you are starting under the mach. Instead, climb to 40k, then descend to the mid-low 30s, that's where you really can get fast. Once you get above about M1.2-1.3 you can slowly begin climbing back. This is doable with bags, I should add, as long as you jettison them when empty. Now, once the bags are off, you can do some really ridiculous things, like M1.8 at 50kft+. But proper initial ascent profile is key. There may be a more optimal ascent profile, but this is just what I personally use.

 

 

[Steelpanther]

thanks for answers. although its a bit disappointing to hear that the F-15 radar is a bit gimped in the game. I was able to occasionally detect bot Vipers in single player at about 55 miles hot co-altitude/lookup (the best range) strictly in the TWS mode. And the worst range was with RWS mode at about 45 miles hot aspect co-altitude. PRF doesnt seem to make a big difference with detection range at least in this scenario trying to detect Viper. At 45miles the bandit has definitely fired already two AMRAAMs which might still be roughly within launch parameters buit at the upper end of it. It appears that inside TWS mode moving the search cone seems to provide best detection where as the RWS mode doesnt detect bandit until too late. But I roughly knew where the bandits would be because it was a single player mission which I made, and this made it a bit easier to try the TWS for searching.

 

Thanks for information about the droptanks drag on F-15. I always took all three drop tanks without giving it much more thought. With the three droptanks and AMRAAM load my initial ascent profile is typically afterburner takeoff, followed by about 15-20 deg steep climb in burner. I reckon the best thing would be to use centerline tank first for the takeoff and initial climb to 30k feet. Apparently Viper has that capacity to individually select and jettison droptanks.

[dundun92]

thanks for answers. although its a bit disappointing to hear that the F-15 radar is a bit gimped in the game. I was able to occasionally detect bot Vipers in single player at about 55 miles hot co-altitude/lookup (the best range) strictly in the TWS mode. And the worst range was with RWS mode at about 45 miles hot aspect co-altitude. PRF doesnt seem to make a big difference with detection range at least in this scenario trying to detect Viper. At 45miles the bandit has definitely fired already two AMRAAMs which might still be roughly within launch parameters buit at the upper end of it. It appears that inside TWS mode moving the search cone seems to provide best detection where as the RWS mode doesnt detect bandit until too late. But I roughly knew where the bandits would be because it was a single player mission which I made, and this made it a bit easier to try the TWS for searching.

 

Actually, RWS from my experience does have a slightly higher detection range (often ill get RWS hits, switch to TWS, and it wont see it for a bit). Also, forgot to mention, you need to use HPRF for the initial detection of targets. Essentially, outside 20nm use HPRF, inside 20nm or if he is cold use MPRF. Never use interleavened imo, it doesnt have enough range vs hot targets to detect it with enough time at high altitude.

 

Thanks for information about the droptanks drag on F-15. I always took all three drop tanks without giving it much more thought. With the three droptanks and AMRAAM load my initial ascent profile is typically afterburner takeoff, followed by about 15-20 deg steep climb in burner. I reckon the best thing would be to use centerline tank first for the takeoff and initial climb to 30k feet. Apparently Viper has that capacity to individually select and jettison droptanks.

The F-15 does not have the ability to jettiston individual tanks. The default order drops the wings first, hence why you only take 2 unless you need the range (which is almost never in DCS). BTW, heres a quote from the F-15C manual about climb profiles:

If at MAX power, climb at 350 knots to 0.95 Mach. If Mach increases above 0.95 at 40° pitch attitude, hold 40° and allow the Mach to increase (Mach will rise only slightly before returning to 0.95). Control climb speed by varying pitch angle.

 

 

 

[TaxDollarsAtWork]

DCS has some odd bugs at the minute for starters the APG-68v5 is behaving more in line with say an APG-68v9 or APG-73,

And the F-15C for one reason or another has the exact same radar detection values as an N001E,

 

If they ever do decide to make an F-15C with an APG-63v1, MIDS, JHMCS, PADs and other niceties it would be more in line with peoples expectations of the plane

[Xenovia]

the F-15's radar is gimped and it really annoys me.

[draconus]

High alt high speed long shots are good for cheap shots and area denial, ok, but you won't get kills against any decent opponent that way, and so should you avoid to fly straight into one. You can try the same tactic if you want to test. Either you or them won't stay long on AB during CAP so it's more about giving the speed and alt advantage to your missiles rather than aircraft alone, after firing or after the fight you go back to MIL or even better fuel saving setting. Are you familiar with cranking and notching already?

 

Use Rctrl+Enter overlay to check your controller inputs in game.

[Steelpanther]

High alt high speed long shots are good for cheap shots and area denial, ok, but you won't get kills against any decent opponent that way, and so should you avoid to fly straight into one. You can try the same tactic if you want to test. Either you or them won't stay long on AB during CAP so it's more about giving the speed and alt advantage to your missiles rather than aircraft alone, after firing or after the fight you go back to MIL or even better fuel saving setting. Are you familiar with cranking and notching already?

 

Use Rctrl+Enter overlay to check your controller inputs in game.

 

thx for tip on the controller.

 

But yea I know what cranking is and I watched some growling f-pole manouver video. Cranking is typically 45deg or more turn away from bandit, keeping him locked at the gimbal limit. In hypothetical 1v1 scenario it reduces closure rate as long as enemy keeps same heading and makes possible missile shot fly longer path. Keeping the lock also helps your own SA. Keeping the lock in case you managed to shoot also provides the midcourse updates to AMRAAM. In case of eagle max possible crank angle should be about 55deg off the nose (within 60deg) I've been practicing it against flanker in the quick mission. I don't know how else to practice against F-16 and the like. Maybe in the mission editor it can be done. I'm not very good with the mission editor I just put planes out there and hope for the best.

 

 

Notching I'm not totally sure about but I heard its something to do with the radar and doppler effect, or maybe it was also about putting the AMRAAM at your 3-9 line, as a purely defensive move.

I've heard online that the notching would somehow lose radar lock with doppler effect but I didn't fully understand it.

If a bandit was notching (beaming) so that the heading crossing angle would be 90deg towards yourself using the radar. It would be true that the enemy would not contribute to the closure rate very much. I would still be moving forwards at lets say 450kts. So I suspect there would still be some closure rate between me and target which may or may not be detectable. It seems as though the true closure rate between sensor platform and target seem to be the key factor in the radar detection, more so than any specific angular geometric arrangement between the sensor and the target. If I was chasing an F-16 in a tailchase flying at closure rate of zero and looking down from above at the F-16. I think I would not be able to see the F-16 probably... (unless the radar could show the difference in pulse return time). I suspect there is some minimum value for closure rate that is the key. I think I read from somewhere that F-15 radar sometimes might see fast moving cars on the ground (probably speedsters!).

 

At the risk of embarrassing myself I will give those above as my thought experiment about notching. I'm not truly sure whats the best way to do it ingame.

 

But I would still say that with eagle's radar headon hot aspect radar detection at 45mile against viper is not exactly speaking inspiring confidence in the eagle's radar equipment. I think with that kind of detection range, you must probably crank immediately and depending on altitude already start defending against long shot AMRAAM.

 

Maybe it would be easier with human GCI operator so that one could maybe ask about specifc bogies what their status was. The bot AWACS just gives some irrelevant bogey dope sometimes.

Or then I just have to guesstimate better in my mind where an enemy could be going towards. That being said the F-16 datalink seems to be more accurate with AWACS info. Because radio call from an eagle to AWACS only gives the rough enemy target aspect not the actual heading. It could very well be that I'm just bad at the game haha!!

[draconus]

Notching I'm not totally sure about but I heard its something to do with the radar and doppler effect, or maybe it was also about putting the AMRAAM at your 3-9 line, as a purely defensive move.

I've heard online that the notching would somehow lose radar lock with doppler effect but I didn't fully understand it.

...

Maybe it would be easier with human GCI operator so that one could maybe ask about specifc bogies what their status was. The bot AWACS just gives some irrelevant bogey dope sometimes.

 

Notching is basically beaming the enemy's radar (flying on its 3-9 line) below him, so you stay at the same doppler frequency as the ground clutter which will filter you out. You're right that the closure rate is still high but equally so is the ground behind you, as seen from the enemy. You should notch either the enemy aircraft (for SARH missiles) or the ARH missile itself when already active.

 

AWACS can only tell you if the target is hot, flanking or cold, but in relatively close encounter versus 1 that's more than enough, plus it's on your RWR usually too.

[dundun92]

There’s no need to defend super early. Thats one of the bigger BVR mistakes. In BVR, you have what is called the Minimum Abort Range (MAR), which is the closest you can get to a bandit and still be able to turn cold, and outrun his shots. Theres no need to do any super aggressive pre defending (although after shooting it is advisable you enter a crank + dive). For example vs a AIM-120C on the deck its 6-7nm, at 20kft its 12nm, and at 40kft its 26nm. As long as you turn cold before reaching the MAR you will always be safe in BVR. So in the example of you and a bandit both at 40kft M1+, youd want to shoot at around 40-45nm (whenever above 25kft and 25nm, be sure to pitch up 30° before firing), then crank + a maybe 30° dive to about 25kft. Once you hit the MAR, begin your abort, a simple split-S is fine. If you were at say 20k, shot range would drop to about 15nm (the reason for the drastic drop is the lack of loft effectiveness under 25kft). The most important thing is to always respect the MAR, unless you want to start notching missiles. Its doable, but when you are new I wouldnt mess with that yet. Focus on kinematically defeating missiles.

 

Also, just my opinion, but I wouldnt use GS for anything but the very basics of BVR. He mixes up terminology quite a bit, and overall often simply doesnt know what he’s talking about. For the basics he’s OK but when it gets into tactics imo he simply isnt the best.

 

As for notching, maybe this diagram will help. You are not trying to get zero closure. You are trying to get the same closure relative to the ground under the bandits aircraft.