[CORRECT AS IS] Braking effectiveness

Can you point me, where I could find the data, so that I could try to make a report?

It's in the performance section of the -1. Here's a copy & paste from the other thread.

------

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!

It's a bad joke that ED moves the brakes bug within minutes of posting into the whish list.

Don't know why some of use care about reporting bugs at all.

It's no fun to waste precious time with digging into manuals and doing tests, only to find out that ED for some inexplicable reason doesn't consider this a bug.

This is quite rude to be honest. I will make a bug report anyway with a track file.

Edit: Have a track now

15C winds calm

approx 30000 lbs, speed approx 130 kts

Touch down 400m / 1300 feet from threshold, ground roll: 1160m / 3800 ft.

That is a total of 5200 feet / 1600m of landing distance !!

Landing distance

In the following track (wind calm / 15C ) I have touched down with approx. 130 kts 400m / 1300 feet from threshold, applied maximum braking (skid marks on the rwy with anti skid on), and stopped after 1160m / 3800 ft ground roll, giving a total landing distance of around 5200 ft /1600 m

5200 ft landing distance is a comfortable autobrake 3 landing with a light 737.

I was given the following data coming from the secret documents:

2600ft ground roll at 30000lbs landing weight. <----> in the track it is 3800 ft

Please investigate! Thank you in advance!

F-18landing_distance.trk

I know that this is comparing apples and oranges, but compare the 3800ft landing roll to the 2400ft landing distance (50ft!) for a lightly loaded A320 ;)

Let's see how long this thread lasts ;)

Mmm....I bet your engines were not really at idle but at ~69% rpm.

Just in case this was your issues, read below:

the f-18 has a flight idle and a ground idle. When you put your physical throttle all the way back before touching down, you are going to flight idle. Then you touch down, Weight on wheels, the ground idle detent in the real airplane would allow you to move the throttle further back. In the sim, you have to wiggle the throttle forward and back again in order to go to ground idle, or your engines will stay at higher RPM.

Many times even if I pull the throttle back *after* touching down, I have the same issue. I am unsure if this is a small bug, or maybe the WoW switch is on the nose gear and that happens to still be in the air while I pull the throttle back.

I bet you did not watch the track I provided. :)

Mmm....I bet your engines were not really at idle but at ~69% rpm

Not in my tests with very similar results. A 50% distance increase due to the difference between flight and ground idle wouldn't be realistic either.

And of course there should be 'slight' difference between antiskid on and off braking ;)

Yeah, getting the hornet safely to the ground and make it stopped before EOR is more stressful than landing on the deck...

It's not a problem when operating from long runways we know from Persian Gulf addon to the game, but

try to land the bird in Novorossiysk with 39,000 pounds...the safety margin is low.

same feeling here

With 30,000 lbs I got 2200ft.

The trick is, land very hard at 110kts, then once slowed to 80 knots or so, turn hard and skid sideways. You will slow down faster skidding sideways than just using the brakes. Doing S-Turns or arcs in the grass while braking also helps reduce your overall linear landing roll.

My second joke answer would have been to use the thrust reverser, but the plane can only spin 180 degrees at higher weights.

With 30,000 lbs I got 2200ft.

 

The trick is, land very hard at 110kts, then once slowed to 80 knots or so, turn hard and skid sideways. You will slow down faster skidding sideways than just using the brakes. Doing S-Turns or arcs in the grass while braking also helps reduce your overall linear landing roll.

 

My second joke answer would have been to use the thrust reverser, but the plane can only spin 180 degrees at higher weights.

I will make this my new standard technique. Never gonna miss that taxiway again! :thumbup:

I'd be really interested if they actually checked the current version (or any version after the initial thread popped up in march) against their data, or just saying that it is correct as is because in fact it was correct before. If I remember correctly there was no problem braking on initial release back then, and it felt quite normal compared to the other planes...

Would someone be wiling to do some really simplified test, like measuring stop distance at low speeds like from 60 kts to zero, and compare it to other planes in the sim?

At low speed it really comes down to simple friction, so it would be hard to explain, why the F15 Su-27, A-10 etc whichever module you have, would have a totally different stop distance (no not saying they should be the exact same, just in the same ballpark somewhere given a max effort braking with anti skid even leaving tyre marks)

Unfortunately will be away from home until next sunday, so can't do it myself now.

searched the Whole YouTube for a video of a complete F18 Landing from touchdown to full stop, but sadly most videos are cut just after nosewheel touchdown or F18 simply dont full stop and keep moving for the taxiway… so i could not have a real decent video reference.

BUT... i did tests, since "nothing can make a proof" but for sure we can compare using our brain logic.

so i took a full-internal fuel F18 and landed it at 136 knots at the very start of the runway,

ended nearly the end of the other side, in line with a tree group near the runway as reference point.

then i took the most heavy plane, su33 with FULL fuel load (and we know it holds waaay more fuel than F18 or any USA plane), landed at 136 knots more or less at the same spot at the start of the runway , and … get to a full stop in HALF the distance, near a radar for reference.

at the same distance that su33 was to full stop, F18 was still to 86 knots !

here i attach the track for the guys interested to examine it.

now, im not expert, but a su33 weighting 64655lb (20944 of fuel) should go longer than a plane weighting 36775lb (10803 of fuel) , even if it has better brakes !

...or put in another way...as i think it should be, its the F18 that should go shorter !

i dont know if its the su33 wrong or the F18 wrong, but all planes are in line with su33, so i tend to think its the F18 the wrong one!

hope it helps.

F18-land-brakes-test.trk

UPDATE!

reading the NATOPS manual (just google: a1-f18ac-nfm-200/210 ) its written at page 289 of the PDF or page 11-259 of the manual, that at gross weight of 32000 lb ,

Landing distance on dry runway is 2700 feet.

in DCS in my test was 4740 feet ! (ok gross weight was 36000 lb, but is not a great difference)

thats more or less in line with what i read here and there , most people mention 2000 feet to 3500 feet depending on how heavy.

for reference for FA18e (E its not C but is quite similar), is stated a 3760 feet at maximum load !

i really wish someone give a look on that, because even if its a minor feature, its not just a "wish list".... its a wish to make it performing like the real one !

thanks !

EDIT:

forgot to say in my research that i found that su30MKI can stop in 670 meters / 2198 feet (minimum , so lets say light on fuel), and in my test the su33 (not the exact same plane, but really similar ) with full fuel used 2930 feet to stop, so the result is in line with the data found .

Here is a video of a real hornet landing at NAS Fallon:

Airport diagram for NAS Fallon [https://www.airports-worldwide.com/img/w/nfl_-_faa_airport_diagram.gif]

From the video it appears that the pilot is landing on Runway 31L. Also from this video we can see which taxiways he passes on his braking run. We can see that he stops between C and E somewhere. Now if we take the entire length of 31L = 14,000ft and look at the diagram we can estimate that C is about 1/3 the length = 4,600ft and E is about 2/3 the length 9,200ft.

From this information we can assume his stopping distance was between 4,600-9,200ft. A range that coincides with the word of real pilots saying 3000ft for takeoff and 6000ft for landing.

What you need to do now is measure the distance in DCS from where you Touchdown to where you Stop. Then compare that to the 6000ft (1NM) figure.

Do you have info that the hornet in the video was on maximum brakes?

No we don't, all we have is two similar braking distances. As seen in the video and as mentioned by pilots.

As for DLEGION's Natops claim: Having read the specified pages and surround pages, there is nothing about braking distance all that is there is info about asymmetric loading limitations. Perhaps there was confusion between ft and ftlbs

Ok. Thanks. I follow all those braking threads with interest because DCS planes have very different braking distances as DELEGION stated. My problem with Hornet's brakes is more the fact that the tires leave skid marks even with anti skid on and braking with 85% wheelbrakes.

I'm just continuing to gather info on that. So thanks for all efforts to get this issue sorted out.

and brake marks kill fps , signaled to dcs team, no news from them about a fix

No we don't, all we have is two similar braking distances. As seen in the video and as mentioned by pilots.

 

As for DLEGION's Natops claim: Having read the specified pages and surround pages, there is nothing about braking distance all that is there is info about asymmetric loading limitations. Perhaps there was confusion between ft and ftlbs

nope. maybe different version? the page 11-259 i have here its named : LANDING DISTANCE CHART , at section XI part 8.

well if also the natops flight manual performance charts of 2006 is not considered a valid source, well i dont know what else will do.

the video you posted obviously fall in the circumstances i described… in this case the F18 just keep going to the taxiway, not using full brakes for sure in the meantime.

i really dont get this negationism, its obvious by logic, its supported by official data, and even all other planes are already in line with that, both in real world and in DCS.

i really dont get why negate things like this. mah.

BTW this material has been declassified, right ? we can talk about it freely ? i just wish to not break any rules about that...