yogipol Posted July 17, 2019 Author Share Posted July 17, 2019 Of course 1st striped white lines or before. As far as I remember all performance calculations for landing according to the civil aviation rules is to be at 50ft over the runway threshold...I don't know how IT works with army, but I do still believe real Hornet does better with braking then the one we have in DCS. Just my two cents HP Reverb, Intel I7 9700K, Zotac GTX 2080Ti, 32GB Ram @4000Mhz Corsair, SDD M.2 500GB Samsung 970 PRO Link to comment Share on other sites More sharing options...
bbrz Posted July 17, 2019 Share Posted July 17, 2019 (edited) Is the approach speed of 125 knots the speed for 39000 pounds? I'm sure 39k pounds is structural limit not field limit to perform safe landing in your case. 125kts = 27500lbs 149kts = 39000lbs @yogipol, if you compare RW performance data with the actcual landing roll you will see that the DCS F/A-18 needs a lot more runway than it should. Btw, no need to be 50ft above the threshold and at e.g. St.Maarten even civil planes are way lower over the threshold ;) Edited July 17, 2019 by bbrz i7-7700K 4.2GHz, 16GB, GTX 1070 Link to comment Share on other sites More sharing options...
Wizard_03 Posted July 17, 2019 Share Posted July 17, 2019 That depends a lot on the plane and it's e.g. not required, (not even recommended) on the F-5 when trying to achieve the minimum landing run. It's just a note that braking is more effective with the flaps up. In the F-86 manual I didn't read anything about raising the flaps either. Neither on the F nor the K. Interestingly the F-86 manual mentions that opening the canopy will increase drag and help shorten the landing distance. In general you are trying to avoid any distraction during the landing run, and fiddling head down with levers and knobs after touchdown is usually to be avoided as much as possible. Quite a few flights ended with the plane sitting on the runway with the gear up instead of the flaps up with this technique ;) Back to the F/A-18: With the very large boards hanging down I doubt that retracting the flaps would put more weight on wheels than they create drag. Furthermore this isn't mentioned in the -1 when shooting for a minimum landing run. According to the -1 the landing roll should be ~2600ft at 30000lbs. With antiskid I need 4000ft and without antiskid (and the associated directional control problems) even a bit less! Antiskid braking is apparently way too weak. Regardless flaps add lift not drag, that’s what they are there for. Reasoning that keeping them lowered helps slow you down is wrong. If anything they increase stopping distance because they reduce brake effectiveness. Not that it really makes a difference in the hornet, but flaps are flaps, not speed brakes. Fact is the hornet has a long ground roll in general because it’s meant for trapping not landing. The tires specifically are way more inflated then ground based aircraft, the brakes aren’t suited for long sustained applications, and it’s directional instability in cross winds makes aerobraking risky. It’s just built for the boat not the field. DCS F/A-18C :sorcerer: Link to comment Share on other sites More sharing options...
bbrz Posted July 17, 2019 Share Posted July 17, 2019 (edited) Regardless flaps add lift not drag, that’s what they are there for. Reasoning that keeping them lowered helps slow you down is wrong. If anything they increase stopping distance because they reduce brake effectiveness. Not that it really makes a difference in the hornet, but flaps are flaps, not speed brakes. You clearly don't know what you are talking about. The first 5-15deg they usually considerable increase lift and only a little drag, anything more and they add much more drag than lift. The reason why flaps usually extend more than e.g. 15deg is that you want to increase drag so that you can keep a higher power setting on approach and speed stability is also higher. The ground roll is rather long, confirmed, but not as long as presently in the DCS F/A-18 ;) Btw, if your flap drag theory would be correct, all Hawker bizjets would have serious design flaw, since they extend the flaps to much greater angle after touchdown to reduce the landing roll due to the increased drag. Edited July 17, 2019 by bbrz i7-7700K 4.2GHz, 16GB, GTX 1070 Link to comment Share on other sites More sharing options...
Wizard_03 Posted July 17, 2019 Share Posted July 17, 2019 You clearly don't know what you are talking about. The first 5-15deg they usually considerable increase lift and only a little drag, anything more and they add much more drag than lift. The reason why flaps usually extend more than e.g. 15deg is that you want to increase drag so that you can keep a higher power setting on approach and speed stability is also higher. The ground roll is rather long, confirmed, but not as long as presently in the DCS F/A-18 ;) Interesting, that must be why they’re called high lift devices, because they add drag. DCS F/A-18C :sorcerer: Link to comment Share on other sites More sharing options...
bbrz Posted July 17, 2019 Share Posted July 17, 2019 Interesting, that must be why they’re called high lift devices, because they add drag. Increasing lift without increasing drag? Are you rewriting basic physics and aerodynamics? :lol: i7-7700K 4.2GHz, 16GB, GTX 1070 Link to comment Share on other sites More sharing options...
Wizard_03 Posted July 17, 2019 Share Posted July 17, 2019 Increasing lift without increasing drag? Are you rewriting basic physics and aerodynamics? :lol: Maybe we shouldn't use them on cat shots then, if they add so much drag. There also appears to be a problem with the FCS because every time I get slow the flaps come out, if they add drag that could be really dangerous too. DCS F/A-18C :sorcerer: Link to comment Share on other sites More sharing options...
Shahdoh Posted July 17, 2019 Share Posted July 17, 2019 Maybe this will help..... https://www.grc.nasa.gov/WWW/k-12/airplane/flap.html Link to comment Share on other sites More sharing options...
yogipol Posted July 17, 2019 Author Share Posted July 17, 2019 @bbrz is right about using flaps and drag to lift ratio using different flaps setting, just to give you basic idea about ground roll on B737 using flaps 30 and 40, have a look at the diagrams below. The higher flap setting, the shorter ground roll is. https://drive.google.com/file/d/1qUclyue7nt0wWSA7Y-4puMLEE1gANipp/view?usp=drivesdk https://drive.google.com/file/d/1HObelWPvUc1leD30rzZVnUGzsYPp5xRw/view?usp=drivesdk HP Reverb, Intel I7 9700K, Zotac GTX 2080Ti, 32GB Ram @4000Mhz Corsair, SDD M.2 500GB Samsung 970 PRO Link to comment Share on other sites More sharing options...
Bunny Clark Posted July 17, 2019 Share Posted July 17, 2019 Maybe we shouldn't use them on cat shots then, if they add so much drag. That's why flaps are set to *half* for takeoff, and *full* for landing. Oil In The Water Hornet Campaign. Bunny's: Form-Fillable Controller Layout PDFs | HOTAS Kneeboards | Checklist Kneeboards Link to comment Share on other sites More sharing options...
bbrz Posted July 18, 2019 Share Posted July 18, 2019 To get back to my original question. I would really like to know why ED puts this into the wish list instead of the bug section. The landing roll is more than 50% longer than it should be, so I'm curious why this is considered to be correct? i7-7700K 4.2GHz, 16GB, GTX 1070 Link to comment Share on other sites More sharing options...
Scofflaw Posted July 18, 2019 Share Posted July 18, 2019 No they increase lift, with flaps up the wings create more downforce, putting more pressure on the tires thus making the braking more effective. Sorry, I should have said flaps increase parasitic and induced drag as well as lift. I can't say whether this is modeled in DCS or not. run come save me Link to comment Share on other sites More sharing options...
HWasp Posted August 1, 2019 Share Posted August 1, 2019 Hornet wheel brake effectiveness Hornet deceleration on ground with wheel brakes (anti skid on) is quite low on a dry runway. If someone has access to landing performance tables for the plane, it would be nice to test her against it. Wheels leave skid marks on the runway, still it decelerates as if it was on ice. Link to comment Share on other sites More sharing options...
Deano87 Posted August 1, 2019 Share Posted August 1, 2019 Hornet deceleration on ground with wheel brakes (anti skid on) is quite low on a dry runway. If someone has access to landing performance tables for the plane, it would be nice to test her against it. Wheels leave skid marks on the runway, still it decelerates as if it was on ice. Yeah it stops like a greased duck being thrown down a slip-n-slide. 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. Link to comment Share on other sites More sharing options...
Scofflaw Posted August 1, 2019 Share Posted August 1, 2019 https://forums.eagle.ru/showthread.php?t=234758 The braking feels super ineffective to me too, but I have 0 flight hours in real hornets. It feels like it's one of the least effective modules when it comes to stopping power. Again, speaking from 0 hours of experience in the real thing. run come save me Link to comment Share on other sites More sharing options...
5e EVC Chappy Posted August 2, 2019 Share Posted August 2, 2019 I noticed RL canadian CF-18 pilots deploy air brakes as soon as the wheels touch the ground so it provides some additional drag and helps slow down quicker See at 0:17 Sent from my SM-T580 using Tapatalk 5e Escadre Virtuelle du Canada / 5 Virtual Wing of Canada Intel i9-9900KF - 8 Cores/16 Threads - 3,6/5,0GHZ / 48GB RAM / Crucial P3 Plus 2TB 3D NAND NVMe M.2 SSD / Crucial P5 1TB 3D NAND NVMe Internal SSD / WD Gold 2TB Enterprise Class HDD / NVIDIA RTX 3090 / HP Reverb G2 / HOTAS Warthog / F/A-18C Hornet HOTAS ADD-ON Grip / WINWING Super Taurus Throttle / Saitek PRO Flight Combat Rudder Pedals / Win 10 Pro Modules owned: P-51D, F-86F, A-10C, M-2000C, F-5E, F-15C, F/A-18C, F-16C Maps: NTTR, Persian Gulf, Syria. Link to comment Share on other sites More sharing options...
kengou Posted August 2, 2019 Share Posted August 2, 2019 Never had a problem stopping the Hornet. Airbrakes out on touchdown and stick fully deflected back once under 100 knots for extra stabilator drag. Brakes under about 50 knots. Virpil WarBRD | Thrustmaster Hornet Grip | Foxx Mount | Thrustmaster TWCS Throttle | Logitech G Throttle Quadrant | VKB T-Rudder IV | TrackIR 5 AMD Ryzen 5 3600 | Nvidia GTX 1060 6GB | 32GB DDR4 3200 | SSD Link to comment Share on other sites More sharing options...
launchedsquid Posted August 2, 2019 Share Posted August 2, 2019 Airbrakes out, full back on stick, throttle to ground idle, if I wasn't on the brakes I'll be off the runway before I get to 50 kts, and the anti-skid does nothing to prevent mile long black lines being left on the runway. Link to comment Share on other sites More sharing options...
bbrz Posted August 2, 2019 Share Posted August 2, 2019 The brakes are definitely incorrectly simulated. There's no almost difference in stopping distance between antiskid on and off braking (slightly better braking with antiskid off!) Landing roll is approximately 50% higher than the flight manual values says, but since ED tagged this issue as 'correct as is' in a similar thread and moved it from bugs to whishlist, I guess we have to live with this issue :( i7-7700K 4.2GHz, 16GB, GTX 1070 Link to comment Share on other sites More sharing options...
XtraChrisP Posted August 2, 2019 Share Posted August 2, 2019 Very rarely have I had a roll-out exceed 100' or so. You light-weights need to be landing on the boat! ;) Link to comment Share on other sites More sharing options...
Longiron Posted August 2, 2019 Share Posted August 2, 2019 Hard to tell until the own ship weights issue gets resolved. Talking about disparity between landing checklist page and rearm window. That being said, they might have some over heating effect being simulated that we’re unaware of. Link to comment Share on other sites More sharing options...
bbrz Posted August 2, 2019 Share Posted August 2, 2019 Hard to tell until the own ship weights issue gets resolved. That being said, they might have some over heating effect being simulated that we’re unaware of. I did all tests with internal fuel only, and no external loads, so no weight difference. If the brakes would be overheating it would be a bug as well since they shouldn't during a normal landing well below max landing weight. i7-7700K 4.2GHz, 16GB, GTX 1070 Link to comment Share on other sites More sharing options...
Kubiz Posted August 2, 2019 Share Posted August 2, 2019 Hornet definitely takes quite long to stop. Comparing to Su-27 even without its landing parachutes it takes more of a runway lenght to stop. GIGABYTE Z390 GAMING X | i5 9600k @4.7 GHz | Noctua NH-U14S | MSI GeForce GTX 1070 Ti @OCed | Patriot 32GB DDR4 2666MHz | 1TB SSD + 1TB HDD | Win10 | Thrustmaster HOTAS Warthog + WarBRD | Saitek Pro Flight Rudder Pedals | 1440p AOC Q2790PQU Link to comment Share on other sites More sharing options...
HWasp Posted August 2, 2019 Share Posted August 2, 2019 The brakes are definitely incorrectly simulated. There's no almost difference in stopping distance between antiskid on and off braking (slightly better braking with antiskid off!) Landing roll is approximately 50% higher than the flight manual values says, but since ED tagged this issue as 'correct as is' in a similar thread and moved it from bugs to whishlist, I guess we have to live with this issue :( It's sad if they ignored a problem like this... Can you point me, where I could find the data, so that I could try to make a report? For those, who don't think that there is a problem, let me give you some real world data from an airliner (B737): At 52000 kg landing weight (ISA / sea level ) and with no reverse thrust, on dry runway landing distance with max manual braking is 4070 ft, or 1240 meters! (vref around 136 kts) This is not even the actual braking distance, since it calculates that you will land 1500ft behind the threshold. Link to comment Share on other sites More sharing options...
ED Team BIGNEWY Posted August 2, 2019 ED Team Share Posted August 2, 2019 Threads merged Forum rules - DCS Crashing? Try this first - Cleanup and Repair - Discord BIGNEWY#8703 - Youtube - Patch Status Windows 11, NVIDIA MSI RTX 3090, Intel® i9-10900K 3.70GHz, 5.30GHz Turbo, Corsair Hydro Series H150i Pro, 64GB DDR @3200, ASUS ROG Strix Z490-F Gaming, HP Reverb G2 Link to comment Share on other sites More sharing options...
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