Wheel Brakes not Working
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airfield that is too short for your weight (check charts)
Is there a table somewhere for a/c weight vs runway length? (I tried to rtfm but I couldn’t find anything.)
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There’s definitely one in the -1-1 you pulled up the other day.
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There’s definitely one in the -1-1 you pulled up the other day.
It’s weird because the BMS dash-1 has so much more detailed info, eg. crosswind limits for various runway conditions, and discussion of the new anti-skid system.
But it kinda leaves out the most important dimension – knowing the length of the runway! This should probably be a doc-bug … or a topic for the Doc subforum.
Trying to land 30k lbs of metal at 180+ kts, is going to need a lot of runway… even on a clear, calm, dry day.
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Yeah, around 4000ft at sea level ISA conditions. Section 7 of that manual.
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I was practicing my landings with a heavy jet (two full bags, 2x2 GBUs) by using the AAR training mission, heavy config (pkg 4980). After refueling, I went to land at home base which is Seoul in that mission. At that point, the gross weight of the jet is approx 39k lbs.
Now, Seoul has two runways, 01 is longer with arrestor cables, while 36 is a shorter one without cables. I am seriously heavy with two full bags and full A-G ordinance. Yet the ATC directs me to the shorter one which is close to impossible to land on in that config without going off the end, while there is a nice longer runway right beside it that even has cables. There were no other flights occupying rwy 01 at the time.
Of course, I could jettison my stores to accomodate the ATCs choice, but that seems excessive and in campaigns you have to manage stores.
My first question, should the ATC not direct me to the better suited runway given my config ?
My second question is: Could we please get cables on the 36 runway as well ?
My third question: Do I simply suck at landing heavies - is anyone able to land a heavy config F-16 on rwy 36 at Seoul and fully stop before end of runway?
Fourth: Where is that elusive section 7 mentioned which tells us runway length given gross weight? I could not find it and did STFMsThanks for any input,
JB -
My third question: Do I simply suck at landing heavies - is anyone able to land a heavy config F-16 on rwy 36 at Seoul and fully stop before end of runway?
TR#13 is a F-16CM-50 taking off with 6x mavs and 2x wing bags… gross weight over 40klbs. (They should call this “takeoff training” … just getting off the ground, that heavy, takes some preparation and focus.)
Seoul is just a few minutes away, to the north, so I gave it a try. ATC directed me to runway 01… I had 10,600lbs remaining. Ok landing, slightly hard touchdown but right at the threshold… kept nose up and aerobraked… nose came down right at the far end of the runway – I stood on the wheelbrakes, and punched through the chainlink fence still doing 70kts. Beat that!
Fourth: Where is that elusive section 7 mentioned which tells us runway length given gross weight? I could not find it and did STFMs
Bluewolf was tacitly suggesting the RL manuals can be found by googling … but directly referencing or linking to such sources is discouraged, on this forum.
Iirc there was a time when all the airbases in KTO were the same length. But with the big world update in 4.35, many airbases have clearly different length (and width) runways. Which is awesome! But… now we need a table of gross-weight and weather condition vs distance, and we also need updated info on kneeboard charts.
And maybe smarter ATC to at least pretend to know or care about our weight. When in doubt, declare an emergency, I suppose. It is probably an emergency/exceptional condition to RTB with that much fuel and ordnance.
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For abnormal situations, one useful thing you can do real world is point out your needs to ATC: Seoul Tower, Falcon 1 requires RWY 01 due heavyweight.
I guess that could be a neat improvement to have for the ATC code at some stage, although Id imagine this would have a little complexity to the arrivals process.
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For twin runway
ATC chooses the ILS equiped for landing and the other for take off
For heavies it will take the longest for take off by passing the ils criteria
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TR#13 is a F-16CM-50 taking off with 6x mavs and 2x wing bags… gross weight over 40klbs. (They should call this “takeoff training” … just getting off the ground, that heavy, takes some preparation and focus.)
Seoul is just a few minutes away, to the north, so I gave it a try. ATC directed me to runway 01… I had 10,600lbs remaining. Ok landing, slightly hard touchdown but right at the threshold… kept nose up and aerobraked… nose came down right at the far end of the runway – I stood on the wheelbrakes, and punched through the chainlink fence still doing 70kts. Beat that!
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And maybe smarter ATC to at least pretend to know or care about our weight. When in doubt, declare an emergency, I suppose. It is probably an emergency/exceptional condition to RTB with that much fuel and ordnance.
Went through that fence as well on all my attempts on 36 Given that we should know (had we the proper training and manuals) that the runway can not support a landing of this kind, declaring an emergency in BMS is a really good suggestion. We can then use the more suited 01 with cables.
For abnormal situations, one useful thing you can do real world is point out your needs to ATC: Seoul Tower, Falcon 1 requires RWY 01 due heavyweight.
I guess that could be a neat improvement to have for the ATC code at some stage, although Id imagine this would have a little complexity to the arrivals process.
Yeah, cables on both runways would solve everything. No need to code complex decision trees in that case.
For twin runway
ATC chooses the ILS equiped for landing and the other for take off
For heavies it will take the longest for take off by passing the ils criteria
OK, good to know that the ATC does take gross weight into account in some aspects. Not for landings, it seems - the ATC would know which runway has cables I suppose?
So if (for the time being) it is the responsibility of the pilot to choose the proper runway, then a procedure would be to ask the ATC for landing, but be prepared to override their “suggestion” by an emergency if they do not give us the arrestor cables equipped one.
I have a couple of ideas more to test, will post back if I find out more
Thanks gents
JB -
I don’t normally have an analog axis mapped to wheelbrakes, so I tried that – hoping to apply some gentle brake pressure while still aerobraking. Out of 5 tries, only once did I manage to come to a stop a few ft before hitting the chainlink fence. I used markpoints to measure the distance from the threshold – it was about 1.4nm. Most of my attempts were 1.5-1.6nm.
That’s almost 10,000 ft … is that expected, for ~39klbs weight?
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Well, that secret document would tell you With a runway of about 8.000 ft, 10.000 goes well past EOR.
My thoughts right now are:
- should the brakes be more powerful (probably not, that has been debated when 4.35 came out), or
- can some anti-slip setting help this landing scenario (probably not, should be activated since they should work like ABS on cars and give shortest possible braking distance), or
- are the runways too short (probably not, they are modelled from the real thing), or
- should a heavy landing be treated as an emergency/unusual landing and cable equipped runways preferred by pilot, or
- since I touch down at approx 185 kts in this config, can landing at lower airspeed be done by discarding the 2.5-degree glide slope rule and go for 4-5 until the last moment, then flaring to dampen the impact?
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Super tough to time the flare… I tried that a couple times. At this weight, vert velocity at touchdown over ~400 ft/min seems to either crush my main gear or result in tail-strike, or both. So to play it safe, I end up wasting a lot of runway to get sink rate under control before touching down.
Here’s what I found works best: land at Kimpo 32R instead! It’s a beautifully modelled airport, just a few minutes away… and 32R is over 11k ft long.
I still take about 1.4nm to come to a stop… but with almost 3,000 ft of runway to spare, it feels much more comfortable (and I feel much less incompetent… lol)
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Couple quick tips I’ve discovered…
- There’s a bit of crosswind in TR#13, landing at Seoul 36R. if you don’t have separate axes for toe brakes, BMS applies some (?) rudder-differential to the wheelbrakes when you hit [K] (or apply brakes via single axis).
I don’t know what that equation looks like, but it feels like even the slightest rudder input reduces braking power significantly. Obviously every inch counts on that runway…
So, get lined up while aerobraking… but actually cheat a couple degrees further to the right, so you don’t have to continue to correct while braking, as the crosswind pushes on your tail. (Or maybe apply yaw-trim instead of rudder axis? Haven’t tried that.)
- Maybe this is just my stick calibration/deadzone but, for some reason, I find a few ticks of pitch-up trim on the approach helps keep me on the ideal glideslope and attitude… allowing me to focus on controlling AOA with the throttle, then flaring at the right time while continuing to manage energy before touchdown.
And, once on the ground, it holds the right attitude to aerobrake quite naturally, without much additional input.
I don’t know if this is in the manual/training or ever done in RL or not…
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That’s a good suggestion - choose your airport wisely given what you know about your gw. I will try the flare timing thing tonight, but sure will not be easy. Probably need to aim for a point well before the threshold so could end up in some trees!
I looked into Seoul and the BMS version is actually about 1500 ft shorter than in real life (https://skyvector.com/airport/RKSM/Seoul-Airport). Not that the real-life length would be fully sufficient for this case either, but it would be closer to what we need.
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Couple quick tips I’ve discovered…
- There’s a bit of crosswind in TR#13, landing at Seoul 36R. if you don’t have separate axes for toe brakes, BMS applies some (?) rudder-differential to the wheelbrakes when you hit [K] (or apply brakes via single axis).
I don’t know what that equation looks like, but it feels like even the slightest rudder input reduces braking power significantly. Obviously every inch counts on that runway…
So, get lined up while aerobraking… but actually cheat a couple degrees further to the right, so you don’t have to continue to correct while braking, as the crosswind pushes on your tail. (Or maybe apply yaw-trim instead of rudder axis? Haven’t tried that.)
- Maybe this is just my stick calibration/deadzone but, for some reason, I find a few ticks of pitch-up trim on the approach helps keep me on the ideal glideslope and attitude… allowing me to focus on controlling AOA with the throttle, then flaring at the right time while continuing to manage energy before touchdown.
And, once on the ground, it holds the right attitude to aerobrake quite naturally, without much additional input.
I don’t know if this is in the manual/training or ever done in RL or not…
I do not have toe brakes, I just use a keybind for the Wheel brakes (K by default). Interesting about the rudder impeding the brakes. I do not apply any wheel brake until I no longer aerobrake, so at about 100 kts of ground speed. By then I am at the end of the runway in this case and the brakes can not hold the plane from going off, I need to be sure I do not apply rudder then. I find that any wheel brake will immediately dump the front wheel down so its either wheel or aero braking. But for cables you need the front wheels to be down.
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I just tried three landings in TR#13 on rwy 36 at Seoul. Gross weight of ~39k. I crushed the gear on one attempt, but managed two. Forgo the rule about landing with fpm at the top of bracket and then transition to 13 dgr flare, that will eat up too many feet of runway. What worked for me is to be established flaring 13 degrees at touchdown and keeping glideslope at 2.5-3 degrees until then. Touchdown must be on the very first piece of tarmac available. Apply airbrakes immediately upon touchdown and tap the wheel brakes briefly and continously while aero-braking, every little bit helps, but not so much to take the AoA out of the aerobrake.
Edit: The AAR training mission has winds coming from 150 degrees, so more of a cross wind/tail wind for runway 36. TR#13 has winds at 300 degrees which I guess helps with the aerobraking to a larger extent?
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This is all very interesting, but why would a pilot ever roll the dice on an overweight landing vs. a Jettison? I keep empty drop tanks IF I did not have to engage A-A but thats it… Lose a plane and pilot or lose inventory, not a choice for me.
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My first question, should the ATC not direct me to the better suited runway given my config ?
ATC just don’t care at all about your confg or weight … It is 100% pilot’s responsabilities to first evaluate/calculate landing performances. If performances do not match, he has to choose another field or limit his weight/configuration.
ATC has nothing to do in this process.
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This is all very interesting, but why would a pilot ever roll the dice on an overweight landing vs. a Jettison? I keep empty drop tanks IF I did not have to engage A-A but thats it… Lose a plane and pilot or lose inventory, not a choice for me.
IRL or even BMS campaign, pretty sure that’s the right answer… I crushed my gear, struck tail or blew a tire in about half of the training test runs I did. And the other half, I plowed through a highway or neighborhood north of the airport.
This is just a sim exercise… learning the ropes and exploring the limits. learning that it’s reasonably safe to land up to ~33klbs on a 9,000ft runway, is valuable knowledge – eg. jettison tanks but keep a pair of HARMs or Mavs.
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IRL or even BMS campaign, pretty sure that’s the right answer… I crushed my gear, struck tail or blew a tire in about half of the training test runs I did. And the other half, I plowed through a highway or neighborhood north of the airport.
This is just a sim exercise… learning the ropes and exploring the limits. learning that it’s reasonably safe to land up to ~33klbs on a 9,000ft runway, is valuable knowledge – eg. jettison tanks but keep a pair of HARMs or Mavs.I guess for me it’s just one of those info overload things, I can’t retain 1/4th of the things I actually should know to thrive and survive a campaign so fringe stuff like this isn’t even on my radar…