greenmamba Posted November 30, 2018 Posted November 30, 2018 This is a question to anyone , Don’t you have the feeling that the fuel tanks have a too high of drag coefficient ? The hornet is a WIP but I really feel like having to wing tanks adds too much drag.
Deano87 Posted December 1, 2018 Posted December 1, 2018 You may have been spoiled by other jets that have big engines and plenty of wing like the F-15. The Hornet was never really blessed with a turn of speed, specially when weighed down with tanks etc. Apart from your gut feeling that it’s too draggy do you have any data to support your feeling? There might be something in the Natops manual about drag penalty for tanks and reasonable cruise power/speeds etc. I dunno <shrug> Proud owner of: PointCTRL VR : Finger Trackers for VR -- Real Simulator : FSSB R3L Force Sensing Stick. -- Deltasim : Force Sensor WH Slew Upgrade -- Mach3Ti Ring : Real Flown Mach 3 SR-71 Titanium, made into an amazing ring. My Fathers Aviation Memoirs: 50 Years of Flying Fun - From Hunter to Spitfire and back again.
donkeyrider Posted December 1, 2018 Posted December 1, 2018 I remember Jello mentioning in one of his podcasts that the legacy Hornet is quite draggy with 2 fuel tanks - he was comparing it to the Super Hornet.
greenmamba Posted December 1, 2018 Author Posted December 1, 2018 You may have been spoiled by other jets that have big engines and plenty of wing like the F-15. The Hornet was never really blessed with a turn of speed, specially when weighed down with tanks etc. Apart from your gut feeling that it’s too draggy do you have any data to support your feeling? There might be something in the Natops manual about drag penalty for tanks and reasonable cruise power/speeds etc. I dunno <shrug> No no i just have my gut feeling, i have no data. But i will get used to the fact that the Hornet gets very draggy with the two wing tanks. I have the F-15 module but never flew it ..... i just flew other sims before that. But i slowly get the feel for the Hornet, i find that anytime i need a bit of speed i either pitch down 5 degrees in the turn or i just unload the plane to 0 G´s or a little AB kick.
greenmamba Posted December 1, 2018 Author Posted December 1, 2018 I remember Jello mentioning in one of his podcasts that the legacy Hornet is quite draggy with 2 fuel tanks - he was comparing it to the Super Hornet. Ah oki, well then i just need to get used to it.
Tenkom Posted December 1, 2018 Posted December 1, 2018 [WIP] Pylon and Stores Drag I want to discuss the drag amount on the launchers for the A-A missiles on the Hornet. Specifically the ones for the aim-120s. I recorded a short video showing the numbers I found: TL;DW: It is a simple straight and level full AB speed test with 2(3) different configurations, Single aim-120c with launchers on inner wing pylons Just the launchers And wing tanks. Speed clean: 822 kts Speed with missiles and launchers: 694 kts Speed with only launchers: 730kts Speed with wing tanks:726kts So the wing tanks are only SLIGHTLY more draggy than just those tiny launchers? This seems very unrealistic to me. It also makes it very painful to fly around with missiles since the plane becomes so slow. I haven't seen anybody mention this and if it really is wrong(and it's not just me being crazy) then it must be a really simple fix.
Eldur Posted December 1, 2018 Posted December 1, 2018 I noticed this right away when the Hornet was new and I mentioned this several times and IIRC someone did a similar test back then, but it hasn't been acklowledged. Those racks look pretty sleek and many have the impression that their drag is way too much. In general, many racks seem to be quite off. Try carrying 8 Mk 83 and 2 Mk 82 for example and do the same test with those, you will be amazed. If you want to see more, repeat with those 6x BDU-33 racks On a side note, even some stores seem to be way off as well. Load up max LAU-61s and see how the Hornet converts into an A-10 with afterburners performance-wise. Don't forget to take a peek at the checklist page there
Eddie Posted December 1, 2018 Posted December 1, 2018 (edited) Drag index for a LAU-115 with 2 LAU-127 is 8.8. With two AIM-120s on the launchers it’s 18.8. Drag index for a single 330 Gal tank on the wing is 14.5. So yes, two AIM-120s is quite draggy, as are the clean launchers. An AIM-120 on the fuselage stations only has a DI of 4. The DI for a single LAU-61 is 31.5, before you account for the BRU-33s, shouldn’t be surprising that 8 of them slows the jet down so much really should it?! Edited December 1, 2018 by Eddie
ED Team Wags Posted December 1, 2018 ED Team Posted December 1, 2018 Pylon drag is WIP. Youtube: https://www.youtube.com/user/wagmatt Twitch: wagmatt System: https://forums.eagle.ru/showthread.php?p=3729544#post3729544
Uberick Posted December 1, 2018 Posted December 1, 2018 Huh, thats interesting. Can we jettison the launchers yet? I remember trying a while back and it didn’t work?
Tenkom Posted December 1, 2018 Posted December 1, 2018 Drag index for a LAU-115 with 2 LAU-127 is 8.8. With two AIM-120s on the launchers it’s 18.8. Drag index for a single 330 Gal tank on the wing is 14.5. So yes, two AIM-120s is quite draggy, as are the clean launchers. An AIM-120 on the fuselage stations only has a DI of 4. The DI for a single LAU-61 is 31.5, before you account for the BRU-33s, shouldn’t be surprising that 8 of them slows the jet down so much really should it?! Where do you get these numbers?
Eldur Posted December 1, 2018 Posted December 1, 2018 Drag index for a LAU-115 with 2 LAU-127 is 8.8. With two AIM-120s on the launchers it’s 18.8. Drag index for a single 330 Gal tank on the wing is 14.5. So yes, two AIM-120s is quite draggy, as are the clean launchers. An AIM-120 on the fuselage stations only has a DI of 4. The DI for a single LAU-61 is 31.5, before you account for the BRU-33s, shouldn’t be surprising that 8 of them slows the jet down so much really should it?! Great to have some numbers, seems reasonable. In case of the LAU-61 there's one thing though: Where are the caps? We have them on the Harrier and F-5E. Are they not being used on the Hornet? (Would ask the same for Zunis) This should reduce the drag quite much. In case of those launchers though a lot of the performance loss also comes from it's sheer overweight. Getting the Hornet up to like 70k lbs is quite easy with those pods in DCS at the moment which is very far from being realistic. Pylon drag is WIP. Thanks for confirming, was kinda expected
Frederf Posted December 1, 2018 Posted December 1, 2018 Clean DI vs 330 gallon on 3/7 is 0 versus 29. With 400 engine (DCS 404) Vmax at MIL at 20,000' 34klb is Clean M0.975 DI 25 M0.960 DI 50 M0.948 Estimated with DI 29, M0.959. That's 599 KTAS clean and 589 KTAS DI 29. OK now you can go check at that weight and altitude is your top MIL speed 10 KTAS slower with the two wing tanks or not?
Fropa Posted December 2, 2018 Posted December 2, 2018 Pylon drag is WIP. This is good to know. Thanks, Wags! :)
WildBillKelsoe Posted October 29, 2019 Posted October 29, 2019 (edited) Drag index for a LAU-115 with 2 LAU-127 is 8.8. With two AIM-120s on the launchers it’s 18.8. Drag index for a single 330 Gal tank on the wing is 14.5. So yes, two AIM-120s is quite draggy, as are the clean launchers. An AIM-120 on the fuselage stations only has a DI of 4. The DI for a single LAU-61 is 31.5, before you account for the BRU-33s, shouldn’t be surprising that 8 of them slows the jet down so much really should it?! How did you get these calculations? Can you show how it is calculated? Nevermind Edited October 29, 2019 by WildBillKelsoe source mentioned AWAITING ED NEW DAMAGE MODEL IMPLEMENTATION FOR WW2 BIRDS Fat T is above, thin T is below. Long T is faster, Short T is slower. Open triangle is AWACS, closed triangle is your own sensors. Double dash is friendly, Single dash is enemy. Circle is friendly. Strobe is jammer. Strobe to dash is under 35 km. HDD is 7 times range key. Radar to 160 km, IRST to 10 km. Stay low, but never slow.
GumidekCZ Posted April 19, 2020 Posted April 19, 2020 (edited) Im not a programmer, but if all these available, should it take so long to fix the drag of all pylons, adapter, weapons? Yeasterday I just use script scanner to search whole DCS about any script mentioning LAU-115C adapter and its drag. Found nothing. Its a mistery how ED scripted drags for all these. FA-18C sample drag index calculation: same can be found for FA-18E/F sample drag index calculation: Missiles: Adapters: store drag interference: These can be found for any weapon/adapter for Hornet (doc for C version not all interfrence data filled, but for E/F version..all is there). When DCS F18C Hornet almost clean configuration, it can be fast as it should be according to this chart: But when anything carried under wings.. its like to fly with aerobrake out. No wonder that other DCS jets can outperform Hornet so easily. Edited April 19, 2020 by GumidekCZ
Airhunter Posted April 19, 2020 Posted April 19, 2020 This is ED, they probably forgot about it. Pylon drag is one of many basic features that are fairly simple to fix/implement that are still missing.
G B Posted April 19, 2020 Posted April 19, 2020 Im not a programmer, but if all these available, should it take so long to fix the drag of all pylons, adapter, weapons? Yeasterday I just use script scanner to search whole DCS about any script mentioning LAU-115C adapter and its drag. Found nothing. Its a mistery how ED scripted drags for all these. FA-18C sample drag index calculation: [ATTACH]233106[/ATTACH] same can be found for FA-18E/F sample drag index calculation: [ATTACH]233107[/ATTACH] Missiles: [ATTACH]233108[/ATTACH] Adapters: [ATTACH]233109[/ATTACH] store drag interference: [ATTACH]233110[/ATTACH] These can be found for any weapon/adapter for Hornet (doc for C version not all interfrence data filled, but for E/F version..all is there). When DCS F18C Hornet almost clean configuration, it can be fast as it should be according to this chart: [ATTACH]233111[/ATTACH] But when anything carried under wings.. its like to fly with aerobrake out. No wonder that other DCS jets can outperform Hornet so easily. The E/F pylons’ drag is in a completely different league than the legacy hornet’s. Interpolation wouldn’t work. Apples to oranges.
GumidekCZ Posted April 19, 2020 Posted April 19, 2020 (edited) The E/F pylons’ drag is in a completely different league than the legacy hornet’s. Interpolation wouldn’t work. Apples to oranges. How do you know? Are you Hornet pilot? or Boeing employee? Even small kid playing with plastic models knows that C and E/F have different dimensions between pylons (E/F has less space between = more interference drag), but can be good data when compared with C version. Edited April 19, 2020 by GumidekCZ
gekoiq Posted April 19, 2020 Posted April 19, 2020 How do you know? Are you Hornet pilot? or Boeing employee? Even small kid playing with plastic models knows that C and E/F have different dimensions between pylons, but can be good data when compared with C version. As it turns out he *is* a Hornet pilot...
G B Posted April 19, 2020 Posted April 19, 2020 As it turns out he *is* a Hornet pilot... And Rhino :).
G B Posted April 19, 2020 Posted April 19, 2020 How do you know? Are you Hornet pilot? or Boeing employee? Even small kid playing with plastic models knows that C and E/F have different dimensions between pylons (E/F has less space between = more interference drag), but can be good data when compared with C version. Not just the size. The geometry too.
maxTRX Posted April 19, 2020 Posted April 19, 2020 Not just the size. The geometry too. I vaguely remember from the SB sim there was some sort of issue with inboard pylons, the angle or something, related to weapon separation characteristics? Another difference between Hornets and Rhinos is the wing shape also. More pronounced "twist" on Hornet's outboard part of the wing?
G B Posted April 19, 2020 Posted April 19, 2020 I vaguely remember from the SB sim there was some sort of issue with inboard pylons, the angle or something, related to weapon separation characteristics? Another difference between Hornets and Rhinos is the wing shape also. More pronounced "twist" on Hornet's outboard part of the wing? The pylons are canted. The inboard ones are the worst. They were initially straight during the design phase, but during testing they calculated there would be weapons separation issues, and the “fix” was to cant the pylons. As it turns out, it was a miscalculation and it was a nonissue, but by the time they realized it, the damage was done and the canted pylons were here to stay. It’s very unfortunate. Do a Google Image Search for Super Hornet Pylons.
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