RTO in a 737 NG

[Cptn Titus]

How do you perform an RTO in a 737NG?
I know that the QRH states to deploy the speedbrakes manually, but is it legal to do it using the autospeedbrake feature, using the reverser?
I know of some major airlines (eg. Air New Zealand, Japan Airlines) that reject, reaching for the reverser first.

[Boneman]

With RTO selected the speedbrake will deploy automatically during an RTO. It is the Captain's responsibility to insure the speedbrake deployed during the rejected T/O procedure. Basically, it's autothrottles - OFF, throttles - IDLE, thrust revers - DEPLOY, then check the speedbrake is deployed. There are a lot of other things that need to be done, like note airspeed at the time of reject, call the tower, run the RTO checklist, etc., etc., but above are the basics.

[BOAC]

The two most important things in an RTO are:
Brakes and
Spoilers
Reverse is secondary.

Boneman - I think you will find that Boeing actually task the F/O with ensuring the speedbrake has deployed and the Captain with doing so(/anyway) if it has not? Your airline may of course differ.

In fact. C Titus, as you will be aware it happens PDQ, BUT there is a sequence where from closing the throttles, F/O checking bits done (including spoilers) and the hand going to 'backup' the action of the autospeedbrake - the hand then goes back to the throttles and on with the reverse.

[Cptn Titus]

Ok, but what would an FAA Inspector say, if I don't deploy the speedbrakes manually, as the QRH states? Would he fail you? Does anyone know how Boeing would respond to this?
Thanks for your inputs!!

[yrvld]

ORH says "Raise the SPEED BRAKE lever"
Then "Apply maximum reverse thrust consistent with conditions".
So, first speed brake, then reverse. Of course, when you select reverse, the speedbrake lever will go up, but the sequence should be first speedbrakes, then reverse.

[BOAC]

We crossed. If they had not automatically deployed and you didn't - I would hope so! Most people 'back it up' anyway after throttles. If it has deployed so much the better.

[Cptn Titus]

Right guys. But what I mean is, what's the point of having such a great automatic feature which could make a difference in real life, and not using it?

[BOAC]

I think you might be a bit confused? Have you actually done an RTO in the sim? The spoilers will be deployed before you can blink (- or say 'Airbus'). The thing is to have your hand going to the lever without delay IN CASE the auto does not work. After all, you cannot raise something that is already raised:)

[Cptn Titus]

Of course Boac, I totally agree with you, but I am talking about the legal part. In practical terms in the simulator, it is as you say. But the fact is the instructor or FAA inspector is actually looking at your hands!! and might call your attention if you don't "manually extend the speedbrake". So, does anyone experienced in the box something like this?
Tks

[pilotguy32]

What´s the reason for noting the brake on speed? Brake cooling times?

[BOAC]

Yes - but the point is you should be moving your hand anyway to be ready, so he/she should see that? When your hand gets there - the lever has gone. It certainly does no harm in giving it a 'tug' anyway which might satisfy this inspector - if they are that pedantic. I cannot see the issue.

[Cptn Titus]

Well BOAC...it happens you know....they could be quite pedantic!
Pilotguy32: Exactly!

[fireflybob]

From the B737-800 manual:-

If the SPEED BRAKE lever is in the DOWN position during landing or rejected
takeoff, the auto speed brake system operates when these conditions occur:
• main landing gear wheels spin up (more than 60 kts)
• both thrust levers are retarded to IDLE
• reverse thrust levers are positioned for reverse thrust.

So speedbrakes will not deploy until reverse thrust selected. This is surely to back up in case speedbrake is not manually selected?

Also:-

• Simultaneously close the thrust levers and disengage the
autothrottle
• Apply maximum manual braking or verify operation of RTO
autobrakes
• Manually raise the speedbrake lever
• Apply maximum reverse thrust and stop the aircraft.

[c100driver]

I know of some major airlines (eg. Air New Zealand, Japan Airlines) that reject, reaching for the reverser first.


I can confirm that Air NZ do not have that procedure for any Boeings

It is:

Close thrust lever and cancel A/T
Raise speed brake
Ensure braking
Select reverse thrust

[SuperRanger]

C.Titus,

This subject was brought up in a mini-symposium at our company last month. According to Boeing Chief Technical Pilot, the reject action is exactly as published in the manuals, in the exact sequence i.e. as posted by fireflybob & c100driver.

However, Boeing has done tests to verify the validity of current reject data using 2 steps reject action i.e. 1. disengage A/T & close thrust levers 2. select reverse. Apparently, for all current boeing types EXCEPT the 737 (all-variants), the stopping distances are negligible.

If your airline wishes to adopt the 2 steps reject action, all you need to do is to write to boeing for a NTO.

Hope this helps.

SR

[Cptn Titus]

Thank you, very much SR!!

[SOPS]

For what it is worth our 777 procedure has changed from "pull the speedbrake manually and then select reverse" to " select reverse and check auto deployment of the speedbrake"

[Boneman]

Verbatum:

During takeoff, the crewmember recognizing the malfunction will call it out
clearly and precisely.

CAPTAIN
Calls “REJECT”
Simultaneously brings both thrust levers to idle and disengages the autothrottles.
Confirms RTO braking or initiates maximum manual braking.
Initiates maximum reverse thrust consistent with runway and aircraft conditions.
Raise speedbrake lever if not already up.
Announces “MANUAL BRAKES” when autobrakes disengage.
Calls for “REJECTED TAKEOFF CHECKLIST.”

FIRST OFFICER
Confirms the following actions:
· Both thrust levers idle.
· Autothrottles disengaged
· RTO or manual brakes.
· Reverse thrust:
· (Calls if other than both reversers operating normally, such as “LEFT
REVERSER ONLY.”)
· Speedbrake lever full up. (If speedbrake lever is not up calls “SPEEDBRAKES.”)
Call “80 KNOTS.”
Calls “MANUAL BRAKES” if not called by the Captain.
Notify Tower/Ground of reject and status.
Notify cabin to “REMAIN SEATED, REMAIN SEATED.”
Accomplish REJECTED TAKEOFF checklist.
* * * *

[ant1]

The 2 step process (thrust levers to idle, apply reverse thrust and check SB up) seems logical to me (but obviously not to Boeing).

Reversers unlocked, automatically mean thrust levers are in idle position and unable to move forward at least on the 737.

As for the autobrake, a 90kts instead of an 80kts call during the T/O roll would apparently be more useful on the 737 as the A/B system won't kick in below that speed.

[Centaurus]

This is surely to back up in case speedbrake is not manually selected?

Precisely that. The reason why Boeing require the speed brake to be actuated manually is that if the auto speed brake function fails to operate you already have the speed brakes deployed. The speed brake/spoiler combination is vital in a high speed abort to get the weight on the wheels for efficient braking as well as the drag effect at high speed. Interestingly Qantas used to require the reverse thrust action to activate the speed brake rather than first applying manual speed brake. This was in contradiction to the Boeing philosophy which has been in the FCTM since years ago. But Qantas has now reverted back to the original Boeing advice of manual speed brake followed reverse thrust where necessary.

Interestingly in the simulator we have observed on many occasions that some pilots rely totally on the operation of the thrust reverser levers to actuate the auto speed brakes on an abort or landing. But the malfunction section on the simulator instructors panel includes a facility to disable the auto-speed brake function. Clearly the certification of the simulator includes the possibility of the auto speed brake malfunctioning. Otherwise why have that malfunction capability? One thing is for sure and that is pilots who rely on the reverse levers to auto actuate the speed brakes often get a shock when they find out seconds later the speed brakes failed to operate automatically. Valuable efficient braking time is lost before someone spots the fact the speed brakes did not operate.

On another point of technique and this is in regard to disengaging the autothrottle system as part of the abort take off procedure. Once throttle hold is annunciated during the take off run, closure of the throttles can take place without the risk of the throttles opening up again during slow down.

But the FCTM states "After THR HLD is annunciated, the thrust levers, when retarded, remain in idle. For procedural consistency, disengage the autothrottles for all rejected take offs".

But what often happens in the simulator when an abort is initiated at high speed is the pilot first presses the disengage button and then rapidly closes the throttles. There is often a slight delay of maybe one or two seconds as the the pilots thumb hits the disengage button in the throttle handle and then he closes the throttles. That slight delay at 140 knots means the aircraft is still accelerating over 200 feet per second before the throttles are whipped closed. The FCTM also states: "if the takeoff is rejected before the THR HLD annunciation, the autothrottle should be disengaged as the thrust levers are moved to idle. [COLOR="Red"]

It does not say before the thrust levers are moved to idle. In other words the pilot should close the throttles and as time permits disengage the autothrottles - as Boeing says "for procedural consistency". There is nothing to say you cannot close the throttles fully and then disengage the AT system.

[alexban]

One other thing, the speedbrakes will raise when the reverser levers are positioned for idle reverse , which will happen not earlier than engines go down to idle thrust. This takes about 2 seconds , so you won't have automatic raise of the speedbrakes untill about 2-3 sec from deciding to RTO.
By Boeing procedure (for the 737 ) , the Cpt will retard the thrust then raise manually the speedbrakes. The engines will be at idle thrust at which time the lock will open and allow reverse thrust application.

[fireflybob]

Centaurus, agree 100%.

Some of us flew a/c like the B707 where there was no auto speedbrake function so to me it is quite natural to make the manual selection on the RTO (or even a normal landing).

Boeing also use the word "simultaneously" which I believe means "at the same time"!

[Callsign Kilo]

The auto speedbrake function on the 737 is just that...a function. As continually said here, it can malfunction!

In the heat of the moment during any RTO there is always potential for something to go amiss, although in my experience it is usually during the later stages when the aircraft has finally came to a stop and malfunction diagnosis, followed by memory items and a possible resultant evacuation occurs (ie NOT stowing the speedbrake lever or ensuring flaps have reached 40 degrees. This has all been observed (thankfully only) in the simulator.

To me the PM call 'speedbrake' or 'no speedbrake' is worth it's weight in gold here. Immediately after any touchdown and equally as soon as an RTO is initiated.

[Todders]

In my company JAR operator and in fact in every sim i have every been in all boeing, all performing boeing sop's you would without question fail your RTO section of the sim if you didn't manually move to, or if your quick extend the speed brakes.

That from my point of view is the legal part for you black and white.
Talk it through and keep it calm:

STOP,
DISCONNECT AND RETARD,
SPEED BRAKE DEPLOY, (At this point the a/c will pitch nose down as the brakes kick in.)
CHECK RTO BRAKING MANUAL IF IT DOESN'T WORK, HEELS ON THE FLOOR IF IT DOES,
REVERS THRUST AS NESS.

[zlin77]

Remember Guys/Gals the QRH is vetted by lawyers & Boeing, they try to publish a watertight procedure so that everything is covered correctly if they go to court......for this reason, speedbrakes are manually deployed before selecting reverse......same procedure on 777..

[The The]

Our procedures to manually raise the speedbrake before initiating reverse thrust were introduced in 2008.

The reason given was due to a tech insertion on later model engines (improving gas flow). This required a new FAA test program that included new requirements for load testing.

The load analysis tested effect on engine components when during an RTO there is limited time for spool down before reverser sleeves translate. If using the auto speedbrake method, the sleeve movement may exceed the design load case. When using the manual speedbrake method, the design load was not exceeded (only an extra second of spool down is required).

Thus the change to SOP's, to require manually raising speedbrake first.

There is no change to field performance as the manual method is used during certification.

[Centaurus]

The engines will be at idle thrust at which time the lock will open and allow reverse thrust application.

Not so, I fear. In a rejected take off from high power, the N1 will have dropped to around 50-60 percent N1 on the way down to idle reverse N1 by the time the throttles hit the stops and the reverse levers are raised.

The action of lifting the reverse levers towards the first detent is what brings up the autospeed brake - not the idle N1 setting. That is why for landing, as soon as touch down on the main wheels occurs reverse should be selected rapidly to take advantage of the relatively high N1 occurring as the engines wind down.

If the throttles are closed at the flare and touch down occures (say) three seconds later the N1 at touchdown will be around 45 percent N1 on the way down to 31% N1. If, at four seconds after touch down, reverse has not been selected, the idle N1 will then fall to ground idle of 22 percent N1

[Jet Man]

In all four airlines I've flown the B737 for the TRE/checker would de-brief the Captain if manual spoilers were not deployed after thrust lever close and auto-throttle disconnect. By itself not a fail/pass item.

[alexban]

Centaurus :
During an RTO positioning the thrust levers to idle thrust and raising the reverser levers to lock will not raise the speedbrakes.
When the sleeves are fully opened ,then you may select reverse thrust, at which time the speedbrakes will deploy.
You may be right, it may not be a question of N1, I am not sure about that.
But it is a delay from the moment you raise the reversers untill you are able to raise the reverser lever to command reverse thrust., about 2 sec, I guess.

[cheakymunkie]

How can you confirm the operation of RTO autobrake?

[b737NGyyc]

How can you confirm the operation of RTO autobrake?

A glareshield shaped dent in one's forehead is usually a good indication. :):)

[747dieseldude]

The reason for Boeing having you manually deploy the SB is simple:
The accelerate-stop distance published in the AFM, and on which all takeoff calculations are based, is based on Maximum Manual Braking and Speedbrakes deployed. The reversers are a bonus not accounted for during calculations.

Therefore, Boeing wants you to first do the two things that will absolutely guarantee that you stop on the runway: Brake and get the SB out.

In order to safeguard for pilot error, they put in RTO which will brake for you if you forget to, and auto-SB which will get them out for you if you forget them.
The auto-SB is intended as a safeguard and not as a primary means of deploying the SB.

Changing the QRH and the order of critical action items during a rejected takeoff is possible, but the airline has to take responsibility and have it approved by their CAA.

For a system to be considered as reliable enough to serve as primary means of operating something, and basing critical takeoff computations on the assumption that it will operate, it has to be of a certain reliability level.

I do not know if the auto-SB system meets these reliability standards to be considered as a primary system with the checklist only having you verify it's operation.

Do you?

[cheakymunkie]

I was asking for that...

But seriously - is that the only way? I was thinking that the autobrake disarm light being extinguished would not give you the info as maybe in never armed.

[RAT 5]

Plus; if you have 1 procedure, and the point about T,R's being a bonus anyway is well made, then when 1 or both T.R's are locked out you will not waste valuable time trying to tear the levers from their mounts. KISS