Oh SWA…how many is this?

[Inverted]

I didn’t mention anything about which deceleration rate to select. Autobrakes dissipate the energy of the aircraft more evenly into both the left and right main wheel assemblies. It’s better than humans at that.

Yep, this is correct. It is sorta two separate arguments. The logic of needing autobrakes at all is one argument, the selection of too high an autobrake for the condition is another.

For instance, BUR I can totally see AB3. Under this condition, the likelihood of heating one side abnormally or stomping on the brakes too quickly and creating too much heat abnormally.

The other side of the coin is using AB1 or 2 with full TR really uses no brake, or very little at all.

I have LCAs tell me to use only AB3 or MAX for ALLLLLLL conditions. I laughed...

 

[Ian_J]

You Eskimo guys have steel or carbon brakes?

 

[Inverted]

You Eskimo guys have steel or carbon brakes?

Both. MAX has carbon, the rest have steel.

 

[Cherokee_Cruiser]

Yep, this is correct. It is sorta two separate arguments. The logic of needing autobrakes at all is one argument, the selection of too high an autobrake for the condition is another.

For instance, BUR I can totally see AB3. Under this condition, the likelihood of heating one side abnormally or stomping on the brakes too quickly and creating too much heat abnormally.

The other side of the coin is using AB1 or 2 with full TR really uses no brake, or very little at all.

I have LCAs tell me to use only AB3 or MAX for ALLLLLLL conditions. I laughed...

Yup, same. Told dame thing in 2020 when I came over.


Downright stupid statement.

Even AB 1, esp in a crosswind. When I land, as CA I have to sweep the speed brake handle. Then I go for TRs. Deploy to the interlock. Takes a second or two. Then deployed outright. All during this time, AB 1 is already doing its job of getting some brakes on to help decel. Once TRs out, AB 1 is no longer applying brake pressure. It’ll then reapply around 80-90 knots as you slow.



Another key point, keep the TRs out at detent 2 or full until 80 knots. I see guys start stowing it at my first call, 100.


KE = 1/2 * m * v^2

Square velocity means 100 knots KE is much more than 80 knots KE.

 

[roundout]

Chonky

Quit one airline working for BigBoi and went to another airline flying BigBoi

 

[MikeD]

Autobrakes.

First world problems.

 

[Roger Roger]

Central to the problem is flying an airplane that has to have Mach Jesus ref speeds so the tail only drags once in a while (when was the last time you did a -900/-9 walk around and didn’t see the tail skid worn down and repainted?) and as pointed out earlier, no real time feedback of brake temperature.

 

[Roger Roger]

Yep, this is correct. It is sorta two separate arguments. The logic of needing autobrakes at all is one argument, the selection of too high an autobrake for the condition is another.

For instance, BUR I can totally see AB3. Under this condition, the likelihood of heating one side abnormally or stomping on the brakes too quickly and creating too much heat abnormally.

The other side of the coin is using AB1 or 2 with full TR really uses no brake, or very little at all.

I have LCAs tell me to use only AB3 or MAX for ALLLLLLL conditions. I laughed...

They tell us in the literature that one big factor in brake heat is speed at initial brake application, which I think is the reason to consider using no autobrakes instead of just a lower setting. Doesn’t matter if you are using 1 or max, once the airplane figures out it’s on the ground (at whatever ludicrous speed you touched down at in SLC with tankered fuel up to near MLW) it’s gonna start braking. If what they tell us is correct, once the TRs are out and the engines spooled AB1 and 2 won’t really do much until the airplane slows and the TRs lose effectiveness, but by then the brakes have already absorbed a • ton of energy by taking that initial hit. And somehow this whole thing has been translated by the training department into, “if you select AB2 on a normal day in Seattle you’ll get a 10 minute lecture on why you shouldn’t use autobrakes unless you have reason to and by the way did you know that AB2 doesn’t do anything until you slow and the TRs lose effectiveness?”

 

[Inverted]

They tell us in the literature that one big factor in brake heat is speed at initial brake application, which I think is the reason to consider using no autobrakes instead of just a lower setting. Doesn’t matter if you are using 1 or max, once the airplane figures out it’s on the ground (at whatever ludicrous speed you touched down at in SLC with tankered fuel up to near MLW) it’s gonna start braking. If what they tell us is correct, once the TRs are out and the engines spooled AB1 and 2 won’t really do much until the airplane slows and the TRs lose effectiveness, but by then the brakes have already absorbed a • ton of energy by taking that initial hit. And somehow this whole thing has been translated by the training department into, “if you select AB2 on a normal day in Seattle you’ll get a 10 minute lecture on why you shouldn’t use autobrakes unless you have reason to and by the way did you know that AB2 doesn’t do anything until you slow and the TRs lose effectiveness?”

AB is calculated when there is WOW but you can get the buckets out fairly quickly. Yes a lot of the heat is generated on the first application but if the application is abrupt, it applies even more unnecessary force. I feel this a lot in the back when I DH, is pilots will slam on the brakes to disengage AB when it was doing the job for them. Why? All that did was apply too much brake at a higher energy just to get on the brakes manually...

AB1 is such a low value that if the airplane has deceleration at all, it doesn't apply any brake. The spoilers autodeploying is enough to slow the airplane down and autobrakes won't even engage brakes.

At least with AB2, the brake application is gradual to the value it is being commanded to, and that value is fairly constant. Pilots pump and modulate the brakes especially if there is any directional control requirements while your toes are up on the pedals.

Again if the situation calls for it, awesome. I like doing AB1 as a backup if I don't slow down on my own. AB2 I use a ton and have never had hot brakes or issues anywhere. LCAs hate AB1 and 2 and say if you are going to use them use AB3 to which I disagree with. It applies too much brake and keeps the brakes engaged. If you need that deceleration value, do it all day long. But I think new hires and new transitions are flying the airplane the way people fly in the sim and it doesn't translate real well to the real world. Hence why we have had a half dozen brake related bulletins in the last year. And thatsa tooooo many bulletins!!! (Italian accent)

 

[Cherokee_Cruiser]

They tell us in the literature that one big factor in brake heat is speed at initial brake application, which I think is the reason to consider using no autobrakes instead of just a lower setting. Doesn’t matter if you are using 1 or max, once the airplane figures out it’s on the ground (at whatever ludicrous speed you touched down at in SLC with tankered fuel up to near MLW) it’s gonna start braking. If what they tell us is correct, once the TRs are out and the engines spooled AB1 and 2 won’t really do much until the airplane slows and the TRs lose effectiveness, but by then the brakes have already absorbed a • ton of energy by taking that initial hit. And somehow this whole thing has been translated by the training department into, “if you select AB2 on a normal day in Seattle you’ll get a 10 minute lecture on why you shouldn’t use autobrakes unless you have reason to and by the way did you know that AB2 doesn’t do anything until you slow and the TRs lose effectiveness?”

AB 1 or 2 and you are prompt on TRs? No big brake hit. No crap Ton of energy hit.


AB 1 or 2 is just fine. It’ll apply initially, completely let off once TRs deployed, then re-apply below 100 knots. It actually is efficient on the brakes.

 

[Cherokee_Cruiser]

This was starting my most recent trip in Seattle. It’s an 8500’ runway.

I had a new FO want to select AB3 for every landing in SEA because it’s SEA.



I don’t like to override how a guy flies, but I told him that was overkill. Told him to try AB 2 and then AB 1, and on his last landing into SEA, don’t use any AB and touch brakes below 100 kts.



He said he was surprised he made P every time.

 

[SurferLucas]

We have a strong contingent that things AB3 is all the -900ER can do

(Has to do with the SFP spoilers, and dragging the tail)

 

[Roger Roger]

We have a strong contingent that things AB3 is all the -900ER can do

(Has to do with the SFP spoilers, and dragging the tail)

Is the logic that the extra spoiler travel causes a nose up pitching moment, and the extra grab of the AB3 helps counter that? It’s not the craziest theory but how does that work out landing in SLC or DEN in the summer with a full boat and a gust additive?

 

[Screaming_Emu]

Central to the problem is flying an airplane that has to have Mach Jesus ref speeds so the tail only drags once in a while (when was the last time you did a -900/-9 walk around and didn’t see the tail skid worn down and repainted?) and as pointed out earlier, no real time feedback of brake temperature.

“The more I learn about that plane the worse it sounds” Screaming Emu said from seat 20E on a 737

 

[SurferLucas]

Is the logic that the extra spoiler travel causes a nose up pitching moment, and the extra grab of the AB3 helps counter that? It’s not the craziest theory but how does that work out landing in SLC or DEN in the summer with a full boat and a gust additive?

That’s the idea…

No joke, I had 3 OE trips. I’m an AB2, Flaps 30, max reverse kinda guy. First LCP says “awesome! You get it”

Next two are former AF guys “you really should be using AB3 on -900’s!!!”

Did Flaps 30, AB3 into ATL on my FAA observation…lead LCP says “why not AB2??”

He and my LCP had a 10 min discussion on it and I texted a few JCer’s that I passed, HA

 

[Inverted]

Is the logic that the extra spoiler travel causes a nose up pitching moment, and the extra grab of the AB3 helps counter that?

It is exacerbated by popping the TRs out with the nose up too. It is like anything on this airplane though, if you know about it, it is just another thing to be conscious of. But none of the LCAs I flew with specified the "why" and on what airplane. Just blanket statements that get people into trouble because it prevents them from thinking.

 

[Roger Roger]

It is exacerbated by popping the TRs out with the nose up too.

I’d have thought TRs would be opposite with the underwing engines

 

[Inverted]

I’d have thought TRs would be opposite with the underwing engines

You'd think. I find all 737s tend to either float when you pop the TRs with the nose up or actually pulls the nose up. It gets an effect that Boeing calls "a Cobra effect"

 

[BEEF SUPREME]

AB is calculated when there is WOW but you can get the buckets out fairly quickly. Yes a lot of the heat is generated on the first application but if the application is abrupt, it applies even more unnecessary force. I feel this a lot in the back when I DH, is pilots will slam on the brakes to disengage AB when it was doing the job for them. Why? All that did was apply too much brake at a higher energy just to get on the brakes manually...

AB1 is such a low value that if the airplane has deceleration at all, it doesn't apply any brake. The spoilers autodeploying is enough to slow the airplane down and autobrakes won't even engage brakes.

At least with AB2, the brake application is gradual to the value it is being commanded to, and that value is fairly constant. Pilots pump and modulate the brakes especially if there is any directional control requirements while your toes are up on the pedals.

Again if the situation calls for it, awesome. I like doing AB1 as a backup if I don't slow down on my own. AB2 I use a ton and have never had hot brakes or issues anywhere. LCAs hate AB1 and 2 and say if you are going to use them use AB3 to which I disagree with. It applies too much brake and keeps the brakes engaged. If you need that deceleration value, do it all day long. But I think new hires and new transitions are flying the airplane the way people fly in the sim and it doesn't translate real well to the real world. Hence why we have had a half dozen brake related bulletins in the last year. And thatsa tooooo many bulletins!!! (Italian accent)

I'm not about to bring a temperature gun in with me to work but I've noticed the brakes are much cooler generally after I land the aircraft than when I walk around a late arriving aircraft. On reserve I DH a lot and I've noticed on average brake applications run from horrible to what feels like pilots intentionally trying to overheat the brakes. On touchdown I feel a strong application of uneven braking which creates a lot of side to side movement in the cabin, then the TRs come out with more side to side movement. The TRs are stowed when the engines are still far above idle power which creates and additional forward moment. That forward moment is stomped on by the already smoking hot brakes creating additional and totally unnecessary kinetic energy transfer. When we are finally off the runway the brakes are chattering at every stopping point in the taxi.

I've never once had chattering brakes as an FO or CA. I think mostly because I'm not trying to exit the runway as soon as possible. Keeping the TRs open until the engines are idle and efficient autobrake use are important factors. However, just basic airmanship and decision making seem to be missing from my DH experience.

 

[MikeD]

I'm not about to bring a temperature gun in with me to work but I've noticed the brakes are much cooler generally after I land the aircraft than when I walk around a late arriving aircraft. On reserve I DH a lot and I've noticed on average brake applications run from horrible to what feels like pilots intentionally trying to overheat the brakes. On touchdown I feel a strong application of uneven braking which creates a lot of side to side movement in the cabin, then the TRs come out with more side to side movement. The TRs are stowed when the engines are still far above idle power which creates and additional forward moment. That forward moment is stomped on by the already smoking hot brakes creating additional and totally unnecessary kinetic energy transfer. When we are finally off the runway the brakes are chattering at every stopping point in the taxi.

I've never once had chattering brakes as an FO or CA. I think mostly because I'm not trying to exit the runway as soon as possible. Keeping the TRs open until the engines are idle and efficient autobrake use are important factors. However, just basic airmanship and decision making seem to be missing from my DH experience.

I cannot believe there are pilots this bad out there on the line, but I’ve had a couple of flights as a pax with unnecessarily heavy brake application and/or pumping post-touchdown, for no seeming good reason. I didn’t receive any specialized training on TR usage and braking when I got into the -200, besides the fact that you had to let the TR pins retract before trying to force the levers up past idle, hence fanning them on touchdown but before the nose was down. I just figured a little finesse with the brakes was appropriate, and operated as such. And it’s worked fine, with not even having to use them much when manually braking.