737 abort procedures

[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 . . .