I'm having a hard time slowing down the MD-11 after touchdown. In several videos, I saw the pilots call for "medium" or even "minimum" autobrakes. If I do this in my plane, I'd overrun the rwy if I'd let only autobrakes do the job - that's for both menu option settings for brakes strength, and e.g. at VHHX (11+k ft rwy) with approx. 370 pax and 20K lbs fuel (i.e. more light weight). To make use of the ultimate high speed exit, I regularily need to fully depress and hold the manual brakes. Cannot think that's "correct" - brakes will probably get very hot this way... BTW, autobrakes work well, they just produce too less effect IMHO...Andreas

Are you sure you aren't having them kick off prematurely because of joystick spikes/conflicts? The amber autobrakes light should be off when they are active, and only light when you take over braking manually. Beyond that, are you using reverse thrust (even popping the reverse doors with an idle decel should be enough)? Are your spoilers deploying (not so much to slow you down by air resistance, but to spill lift from the wing and put more weight on the wheels to make the brakes more effective)?I know they're simple questions, but you didn't specify, so I'm asking.By the way, 370 passengers is a pretty heavy load and I'm assuming you're carrying quite a bit of bags as well. Even without fuel, you're heavier than most flights you would have normally seen in the MD-11 (mixed class can't even handle 370, and most I've seen are mixed). That said, running the numbers (370 pax, appropriate cargo for that, and 20.0 in fuel at destination) through TOPCAT, with no wind and a standard day (+15 and 29.92/1013) and flap 35, you should have 5000' remaining with AUTO MIN.For clarification, are you talking about VHHH or VHHX?

I'm at work right now so I'm not 100% sure about this, but in the MD11 options isn't there a 'high-deceleration' brake option you can select? Have a look and try that.If I'm mistaken, apologies, I know I've seen this feature on an aircraft I have, but not 100% sure it's the MD11.

I'm at work right now so I'm not 100% sure about this, but in the MD11 options isn't there a 'high-deceleration' brake option you can select? Have a look and try that.

Tried already, is a bit better, but I've still the impression that autobrakes are too poor...

Are you sure you aren't having them kick off prematurely because of joystick spikes/conflicts? The amber autobrakes light should be off when they are active, and only light when you take over braking manually. Beyond that, are you using reverse thrust (even popping the reverse doors with an idle decel should be enough)? Are your spoilers deploying (not so much to slow you down by air resistance, but to spill lift from the wing and put more weight on the wheels to make the brakes more effective)?

No spikes from hardware, and spoilers deploy properly...

For clarification, are you talking about VHHH or VHHX?

It's VHHX...Anyway, maybe I'm the only one having this kind of "problem"... Thank you for your tips.

In the case of the old VHHH (called VHHX for the purposes of FS only, to allow the use of both airports in the sim), while the runway is 11,000' long, you may not actually be 'using' all of it. If you're flying the IGS 13, are you actually touching down near the aim bars, or are you floating a good bit down? With a normal approach (straight in), it's relatively easy to hit the aim point and stop normally. At VHH[X], with that tight last turn, you may be well past those markers and will not be able to use the brakes until you're down, later than normal.Are you having the same issue at other airports, with straight in approaches? Try using something open, with a long runway (KIAD, KDFW, KATL, etc) and post your results.

Strange, I have always thought the opposite. Brake action on most addons are completely unrealistic and too powerful. For that reason I use TSR autobrake and the modified friction dll.

Are you sure you aren't having them kick off prematurely because of joystick spikes/conflicts? The amber autobrakes light should be off when they are active, and only light when you take over braking manually. Beyond that, are you using reverse thrust (even popping the reverse doors with an idle decel should be enough)? Are your spoilers deploying (not so much to slow you down by air resistance, but to spill lift from the wing and put more weight on the wheels to make the brakes more effective)?

Actually, in real life, the reversers don't provide very much stopping power at all. The spoilers provide better stopping action. The reason for this (only applicable to petal and cascade reversers; MD11 has cascade) is that only the bypass air is redirected. The thrust from the jet engine itself is still being shot out the back of the engine providing forward thrust. Basically you never get more than about 80% reverse thrust at best; the other 20% of course being the forward thrust. Idle reverse simply has forward thrust equaling reverse thrust. This is actually why the engine sounds louder inside and even outside during reverse; the bypass air normally dampening the sound isn't there anymore since its being shot forward. I can actually hear the reversers (just) of aircraft landing at HNL over 7nm away from my house.Also notice the engines on those KC-135 tankers. They don't have reversers because the Air Force saw it as cheaper maintenance wise. For the airlines, its more a liability thing. For private jets, IF they have reversers, they're typically clamshell types and all the thrust is shot forward.

By the way, 370 passengers is a pretty heavy load and I'm assuming you're carrying quite a bit of bags as well. Even without fuel, you're heavier than most flights you would have normally seen in the MD-11 (mixed class can't even handle 370, and most I've seen are mixed). That said, running the numbers (370 pax, appropriate cargo for that, and 20.0 in fuel at destination) through TOPCAT, with no wind and a standard day (+15 and 29.92/1013) and flap 35, you should have 5000' remaining with AUTO MIN.

Agreed. If you are within max landing weight and you touchdown at the TDZ (Touch Down Zone; the big white blocks or sometimes they look like over pixelated arrows outside the US), you should have more than enough stopping power, even without high decel brakes. I never use that option in FS and find that the auto brakes to a little too well of a job. Even with manual braking, I never fully depress my brake pedals.

To make use of the ultimate high speed exit, I regularily need to fully depress and hold the manual brakes. Cannot think that's "correct" - brakes will probably get very hot this way.

While, yes, they will get hot, the brakes can handle this with no problem. Remember that the anti-skid system will prevent the brakes from being applied so much that it will lock the wheels. Also, you have practically no forward thrust and lots of drag from the spoilers and flaps. Also, the aircraft was decelerating anyway before you applied the brakes. In the flare, with the engines spooling to idle and the higher angle of attack, you have drag increasing and thrust dropping off. Then at touch down, you have the spoilers deploying and the reverser sleeves opening. Finally the nose gear touches down and the brakes can be applied. The aircraft (should) stop quickly and the amount of time you need to apply the brakes that hard will be limited.Now during an RTO (lets assume a rejection at V1), the aircraft was accelerating. This means that when you initiate the RTO, you still have forward thrust and lots of it. The brakes (and spoilers but thats another story) have to first stop the acceleration while the engine spool down. This can take up to about 5 seconds. Then they have to slow the aircraft typically to a stop. This generates way more heat than standing on the brakes during a landing roll.

Actually, in real life, the reversers don't provide very much stopping power at all. The spoilers provide better stopping action. The reason for this (only applicable to petal and cascade reversers; MD11 has cascade) is that only the bypass air is redirected. The thrust from the jet engine itself is still being shot out the back of the engine providing forward thrust. Basically you never get more than about 80% reverse thrust at best; the other 20% of course being the forward thrust. Idle reverse simply has forward thrust equaling reverse thrust.

Thus why I said "even popping the reverse doors with an idle decel should be enough."And "Are your spoilers deploying (not so much to slow you down by air resistance, but to spill lift from the wing and put more weight on the wheels to make the brakes more effective)?"Thanks for clarifying those points, though. The rest of the information is pretty cool, and now that I think about it, makes a ton of sense:

This is actually why the engine sounds louder inside and even outside during reverse; the bypass air normally dampening the sound isn't there anymore since its being shot forward. I can actually hear the reversers (just) of aircraft landing at HNL over 7nm away from my house.

In terms of drag, spoilers are really only there to satisfy their name: spoil lift. In a pure Stick and Rudder sense, the net effect of deploying spoilers is probably only a slight increase in drag, considering the direct relationship between increased lift and increased drag. Sure, their deflection into the airstream causes drag, but also kills lift, which decreases drag. At deployment, drag is ever decreasing as the relative wind decreases, so the idea of the spoilers is really to get the weight on the wheels earlier/faster. Also, if you think back to private pilot training, you may recall when making a short field landing it is also advisable to raise the flaps. Similarly, to stop faster in a jet, you'd come in full flap, and ideally raise the flaps upon touchdown, but safety and flap retraction times would render that inadvisable and ineffective, respectively.

In terms of drag, spoilers are really only there to satisfy their name: spoil lift. In a pure Stick and Rudder sense, the net effect of deploying spoilers is probably only a slight increase in drag, considering the direct relationship between increased lift and increased drag. Sure, their deflection into the airstream causes drag, but also kills lift, which decreases drag. At deployment, drag is ever decreasing as the relative wind decreases, so the idea of the spoilers is really to get the weight on the wheels earlier/faster. Also, if you think back to private pilot training, you may recall when making a short field landing it is also advisable to raise the flaps. Similarly, to stop faster in a jet, you'd come in full flap, and ideally raise the flaps upon touchdown, but safety and flap retraction times would render that inadvisable and ineffective, respectively.

Absolutely. I was just refering to the stopping power of reversers vs. spoilers. But retracting the flap is sort of a double edge sword. Yeah, it gets rid of the lift and gives better braking action, but also it gets rid of the drag caused by lift. In the grand scheme of things it really doesn't make a difference but just noting it. In the light aircraft i fly (I guess it could be different in jets, I only took a small theory workshop), the first few sets of flaps provide more lift than drag. The last set provides more additional drag than additional lift. Also, as a multi engine rated pilot and someone who nearly pulled the wrong lever after landing once, I never ever touch anything until having turned off the runway and am taxiing in. Of course the time I nearly pulled the gear lever up was after we were at a complete stop on a taxiway. Sure the antiretraction valve might've stopped the gear coming up but the school i was with wasn't exactly known for good maintanace.

Absolutely. I was just refering to the stopping power of reversers vs. spoilers. But retracting the flap is sort of a double edge sword. Yeah, it gets rid of the lift and gives better braking action, but also it gets rid of the drag caused by lift. In the grand scheme of things it really doesn't make a difference but just noting it. In the light aircraft i fly (I guess it could be different in jets, I only took a small theory workshop), the first few sets of flaps provide more lift than drag. The last set provides more additional drag than additional lift.

That it is. I never took any formal fluid dynamics courses, so I'm just going off of books and conversations with my college roommate (Aero Eng major), so I'm right with ya, and I was taught/told the same about the flaps. At a certain point, the added drag overtakes the added lift. On a 172, I was told that split was between 20 and 30 degrees. I'm guessing that the variable would be the aerodynamic properties of the wing and how much area the flaps have in comparison, but I haven't the slightest clue.

Also, as a multi engine rated pilot and someone who nearly pulled the wrong lever after landing once, I never ever touch anything until having turned off the runway and am taxiing in. Of course the time I nearly pulled the gear lever up was after we were at a complete stop on a taxiway. Sure the antiretraction valve might've stopped the gear coming up but the school i was with wasn't exactly known for good maintanace.

That was one of my factors in the whole safety comment. At 300+ knots across the ground, I have a controller and an autopilot keeping me from hitting things. At a decelerating 150, the last thing I want to do is look down or reach around blindly, and as mentioned, the difference is negligible in larger aircraft because of the time it takes to retract the flaps, and the other points mentioned.