737 abort procedures

[firstthird]

I'm having a 'discussion' with some of my SWA brethern about RTO procedures. Question is this, how do most 737 operators do their abort?

In the Navy, ours was like this
1 - AT - disengage
2 - thrust levers - idle
3 - wheel brakes - maximum
4 - thrust reversers - max
5 - speed brakes - verify deployed

at SWA
1 - thrust levers - idle
2 - wheel brakes - max
3 - speed brakes - up
4 - thrust reversers - max

last two steps are the crux, thrust reversers first and let the speed brakes auto-deploy, or do most 737 operators get the speed brakes and then do thrust reversers.

thanks for any answers, not particularly important, just a beer bet type discussion.

 

[Super Monkey]

Continental Procedures:

Autothrottles - Disconnect
Thrust Levers - Idle
Thrust Reversers - Max
Verify Speed Break Lever - Up
(Autobrakes Condition - RTO (Rejected Take Off)

Yeah I believe the 737 speed brakes deploy automatically when your above 80 knots and you initiate the RTO by bringing the thrust levers to idle and crack the reversers, which also commands the autobrakes to go full brake pressure in the RTO position.

With the autobrake system, if it was a brake problem and one truck locked up and the other didn't, that could be a bad thing.

My thoughts and prayers are with the crew. Good job for not making it a worse situation.

 

[Andy Neill]

In any of those procedures, what is the effect of the thrust reversers with one engine out?

 

[BEfly]

Good job for not making it a worse situation.

how could it have been worse

 

[SIU 130]

Out of my Boeing 737 Operations Manual:

"RTO auto brakes are aviable only after the aircraft has exceeded approx. 90 knots "wheel speed" during T/O roll.

FAA base line, balanced field length (all engines RTO and EO takeoff, using brakes and spoilers only, no thrust reverse) decission at V1 stop in remaining runway i.e last brick stop.. go last brlck +35 feet in the air

RTO one engine out,reverse thrust, brakes, spoliers = last brick -220ft

Both engines operating two in reverse, brakes, spoliers = last brick -150 ft....no speedbrakes no reverse = last brick +430 ft (you would depart the RWY @ aprox 60 kts)

Less braking effort, all-engines RTO,3/4 brake pressure + speed brakes and 2 in reverse = last brick +260 ft

****effect of blown tire all engine RTO, brakes,speed brakes, 2 in rev = last brick +290 depart runway @ 45 kts

ALL DATA IS BASED ON BALANCED FIELD LENGTH!!!!!

 

[Dude]

how could it have been worse

Seriously?

People could have DIED! There were no fatalities and from what it looks like, the entire crew is the primary reason.

 

[SuperFLUF]

...

at SWA
1 - thrust levers - idle
2 - wheel brakes - max
3 - speed brakes - up
4 - thrust reversers - max

...

CAL used to do it in that order until we convinced somebody that it might be a better idea to let the automation work to deploy the speed brakes and in turn, get those reversers deployed sooner.

 

[SuperFLUF]

Seriously?

People could have DIED! There were no fatalities and from what it looks like, the entire crew is the primary reason.

Amen to that.


How could it have been worse? So many different ways.

If it had happened on 15L at IAH they might have been in to the hangars,
4L in EWR: the aircraft lined up on the taxiway.

 

[Jon Rivoli]

34R at KDEN I don't think runway length would be a problem. I was thinking more like 30 kt crosswind, speed below VMCG and a failure of the upwind engine. You could run out of rudder really fast and find yourself drifting off the pavement quicker than you can say "your choice of expletive here". If there happens to be a big ravine just off the side of the runway, double fudge. Fortunately everyone lived so the NTSB will get a first hand account of what really happened on this one.

 

[ERfly]

CAL used to do it in that order until we convinced somebody that it might be a better idea to let the automation work to deploy the speed brakes and in turn, get those reversers deployed sooner.

Could this have something to do with the -200s not having automatic spoilers and this is a carry over from that? I thought I heard where you had to manually deploy the spoilers on landing. I know both airlines previously operated the -200.

 

[GuppyWN]

Could this have something to do with the -200s not having automatic spoilers and this is a carry over from that? I thought I heard where you had to manually deploy the spoilers on landing. I know both airlines previously operated the -200.

You got it Toyota. Except Southwest can't seem to get over the fact that the -200 has been gone for 6 years! Heck we just started using autobrakes last year.

Gup

 

[EatinRamen]

I fly the-200ADV and we've got automatic spoilers just like the newer models.

 

[ImbracableCrunk]

Most of the guys I fly with think they're still on the -200.

"Well on the -200, ya had yada yada would stop on a dime yada yada climb at the barber pole, descend at the barber pole yada yada turn that off, we didn't have that in the -200 yada yada V2 is always 130 yada yada EFF that V-nav."

 

[igneousy2]

Alaska...

1. Thrust Levers Idle/Autothrottle - Disengage
2. Brakes - monitor auto-brake
3. Speed Brake - Verify Full Up​

4. Reverse thrust- as required.

My personal opinion is that reverse should be last as you technically don't need it at all to stop in time. If the last thing you are trained to do is look at the brakes/speed brakes then I can see it becoming a problem if the auto-system fails/is MEL'd and you don't catch the problem until after the reverse is out.

Anyway, probably doesn't matter that much as long as you get everything done.

Later

​

 

[Whataburger]

In any of those procedures, what is the effect of the thrust reversers with one engine out?

1/2 as much as with 2 engines.

 

[Whataburger]

How could it have been worse? So many different ways.

.

http://extras.mnginteractive.com/live/media/site36/2008/1222/20081222_120721_CD22CRASH_GRAPH.pdf
Makes ya wonder.

 

[slaquer5]

Most of the guys I fly with think they're still on the -200.

"Well on the -200, ya had yada yada would stop on a dime yada yada climb at the barber pole, descend at the barber pole yada yada turn that off, we didn't have that in the -200 yada yada V2 is always 130 yada yada EFF that V-nav."

Funny, next time ask how it climbed, about 500 fpm and with the anti ice on a c-150 could out climb it. I use to call the anti- ice switches the anti climb switches on the 200.

 

[Andy Neill]

1/2 as much as with 2 engines.

...and with no problematic adverse yaw?

 

[b707guy]

I use to call the anti- ice switches the anti climb switches on the 200.

I'll guess it still climbed better with the "anti-climb" on than with them off and in icing conditions...

For dinosaur jockeys like me, max brake application comes first in the laundry list of things to do during a rejected takeoff. I presume that in some of those new-fangled jets that RTO braking is activated by pulling the throttles back to idle, and so the throttle reduction has to come first to bring all the other automated stuff into action, but from firstthird's account of SWAs procedures, wouldn't max brake application (second on the list) trip off RTO braking, if you're using it? Or is that step a verification that the auto brakes are engaged and working? Either way, without auto brakes, max braking should come first, or at least simultaneous with throttle reduction to get stopped in the shortest distance.

 

[jimcav]

Even with automatic spoilers you have few seconds between reverser deployment and the unlock process before you can move the levers beyond the first detent. I use that pause to ensure the speedbrake lever is "up",then go back to the reversers.

 

[sg737]

I always thought that the reason for speed brakes before thrust reversers was because speed brakes are part of the performance equation, and thrust reversers are not.....

 

[Fox-Tree]

CAL used to do it in that order until we convinced somebody that it might be a better idea to let the automation work to deploy the speed brakes and in turn, get those reversers deployed sooner.

That logic makes no sense considering thrust reversers are not part of any takeoff performance data and are not considered in RTO capability.

Continental Procedures:

Autothrottles - Disconnect
Thrust Levers - Idle
Thrust Reversers - Max
Verify Speed Break Lever - Up
(Autobrakes Condition - RTO (Rejected Take Off)

Super Monkey,
Does this procedure indicate that CAL relies on autobrakes during an RTO and doesn’t manually activate max braking? I was under the impression that the FAA mandated manual braking in lieu of reliance on automated brakes (as opposed to foreign operators who have gone the other direction).

 

[SuperFLUF]

That logic makes no sense considering thrust reversers are not part of any takeoff performance data and are not considered in RTO capability.

It makes no sense to use the thrust reverser RTO automation to deploy the speedbrakes because reverse thrust is not considered for takeoff performance planning?

To me, that makes no sense. If you have them, use them.
Deploying the reversers takes the same amount of time as manually deploying the speed brakes and you get two for one with the reverse levers during an RTO.

Super Monkey,
Does this procedure indicate that CAL relies on auto-brakes during an RTO and doesn't’t manually activate max braking? I was under the impression that the FAA mandated manual braking in lieu of reliance on automated brakes (as opposed to foreign operators who have gone the other direction).

Yes, CAL procedures and instruction for RTO's relies on RTO auto-brakes. We are trained to not over ride the auto-brakes.

 

[Fox-Tree]

SuperFLUF,
Interesting about the autobrakes. All 3 airlines I've worked for have required manual braking (which obviously turns off the a/b). I've asked the question and got the "FAA requires it" answer which is obviously wrong. Maybe since all 3 airlines have had a mix of autobrake and non-AB aircraft they tried to keep the procedures standard?

The reverser discussion still doesn't make much sense to me. Wheel brakes are the number one and only expected method of stopping an aircraft during an RTO (TRs are gravy). In order to make those wheel brakes as effective as possible, spoilers are critical. Using a "gravy" system to actuate spoilers via automation instead of manually obviously leaves potential for automation failure. Now this must be realized and reacted to with a manual deployment as a backup, wasting critical seconds during an RTO. Personally, it makes more sense to me to get the spoilers out asap with a direct action than to wait for auto-deployment via TR actuation. JMO.

My 737 systems knowledge is pretty fuzzy by now but do they all actuate spoilers during an RTO via the TRs? Most aircraft I've flown use throttles to idle as the cue for spoiler deployment during an RTO.
Thanks.

 

[SuperFLUF]

SuperFLUF,
Interesting about the autobrakes. All 3 airlines I've worked for have required manual braking (which obviously turns off the a/b). I've asked the question and got the "FAA requires it" answer which is obviously wrong. Maybe since all 3 airlines have had a mix of autobrake and non-AB aircraft they tried to keep the procedures standard?.

That's probably it. It could also be an interpretation difference between POI's?
When we changed our procedures, I was a first officer and don't really remember if any sort of expanded explanation was given. (since at the time it didn't affect my tasks during a reject)

The reverser discussion still doesn't make much sense to me. Wheel brakes are the number one and only expected method of stopping an aircraft during an RTO (TRs are gravy). In order to make those wheel brakes as effective as possible, spoilers are critical. Using a "gravy" system to actuate spoilers via automation instead of manually obviously leaves potential for automation failure. Now this must be realized and reacted to with a manual deployment as a backup, wasting critical seconds during an RTO. Personally, it makes more sense to me to get the spoilers out asap with a direct action than to wait for auto-deployment via TR actuation. JMO.

I can see your point and I'm not sure if its just part of the move towards letting automation do more of the work or not? It may have changed as a result of FOQA and ASAP data analysis?
We do have to verify the speedbrake extends and the FO is required to verify it as well.
There really is no time delay on the speedbrakes by using the TR's to deploy them (if its done right). One added benefit is that the autothrottles will disconnect when you deploy the TR's so if you forget to punch them off, the power won't come back up when you move your hand from the throttles to the speedbrake lever. (seen that one in the sim a bunch)

My 737 systems knowledge is pretty fuzzy by now but do they all actuate spoilers during an RTO via the TRs? Most aircraft I've flown use throttles to idle as the cue for spoiler deployment during an RTO.
Thanks.

On the 300 thru 900, the spoilers only auto deploy on takeoff if the reversers are deployed above 60kts. The RTO autobrakes are cued off of the throttles.

 

[AK737FO]

Back in the day when Alaska flew real airplanes... all our 200's had auto spoilers and auto breaks. None of our 200's had RTO. The spoilers would come up on a high speed abort, but no breaks.
We didn't use the auto breaks much, actually I only remember seeing it used a few times in about 8 years. Don't really know why - we just got along fine with our feet.
As far as our abort goes - it was Idle, Breaks, Boards, Buckets. Man I miss the buckets. These fan engines just make noise compaired to what the 200's buckets would do.
We had JT8D-17's with gravel kits, and the anti ice switch had no effect on our climb performance.
We start a new year and once again I find myself missing my old airplane. I will never be as good a pilot as I once was in that airplane. This purple line flight director stuff will suck the brains out of you.

 

[FatesPawn]

The reverser discussion still doesn't make much sense to me. Wheel brakes are the number one and only expected method of stopping an aircraft during an RTO (TRs are gravy).

Fox,

Here's why it makes CRITICAL sense to Southwest pilots to understand:

In the -700 Stopping margin is based on all-engines operating. In the -300/500 It is single engine. Of course, why would one abort just prior to V1? An engine failure of course.

While TR's are "gravy" on a dry runway for us, on anything but a DRY runway, TR's ARE included in our accelerate stop computations (3/5/7).

So, when we plug our numbers into anything but a DRY runway, we are basically getting a "wag" that DOES include the use of reverse thrust in it's attempt to define what our accelerate stop distance is.

This issue was front and center to us after the MDW accident with regard to our landing data - but that's another thread.

-fate

 

[ImbracableCrunk]

Back in the day when Alaska flew real airplanes... all our 200's had auto spoilers and auto breaks. None of our 200's had RTO. The spoilers would come up on a high speed abort, but no breaks.
We didn't use the auto breaks much, actually I only remember seeing it used a few times in about 8 years. Don't really know why - we just got along fine with our feet.
As far as our abort goes - it was Idle, Breaks, Boards, Buckets. Man I miss the buckets. These fan engines just make noise compaired to what the 200's buckets would do.
We had JT8D-17's with gravel kits, and the anti ice switch had no effect on our climb performance.
We start a new year and once again I find myself missing my old airplane. I will never be as good a pilot as I once was in that airplane. This purple line flight director stuff will suck the brains out of you.

Built in heat and massage, all the FAs were hot, the plane could land backwards inverted and taxi in on the vertical stab . . .