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twilfert

How to perform a rejected take off

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Hello,

my question might sound a bit stupid but I could not find anything about this topic on the net.

After already in take off mode, I tried to reject the take off by just pulling back the throttles at my joystick but the aircraft continued to accelerate for take off.

What do I need to do to reject the take off?

I would be very thankful if you could help me here.

 

Thanks very much in advance.

 

Tilo

 

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What do I need to do to reject the take off?

 

Ensure your A/T setting in the PMDG SETUP menus is set to allow the hardware to override in HOLD/ARM MODE.  Sounds like the sim is just ignoring your hardware.

 

The steps for rejecting throttle are as follows:

  1. Pull throttles back to idle
  2. Done

(Provided your autobrake is set to RTO)

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Thanks so much. The A/T setting in the PMDG Setup menu was exactly the missing item. It works now:)

 

Kind regards,

Tilo

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The steps for rejecting throttle are as follows:
Pull throttles back to idle
Done
(Provided your autobrake is set to RTO)
Idle, or reverse? I realize if you have lost an engine you probably don't want that one in reverse in case it makes things worse.

 

In this vid they use REV even though something went wrong in Number 2 Engine

https://www.youtube.com/watch?v=PS1YAX70edc

 

In this vid they don't - although it is at Airbus plant so possibly during testing they may have not used it.

https://www.youtube.com/watch?v=sn7JHwRPKf4#t=68

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Additional comments:

 

Your speed at the time you decide to reject the take off, *must* be less than V1 (you probably already know this).

 

I would also use reverse thrust (if both engines are running normally) to help me stop the airplane.

 

I would ensure the speed brakes were deployed (up) and if for some reason they were not, I'd manually extend them immediately.

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Idle, or reverse? I realize if you have lost an engine you probably don't want that one in reverse in case it makes things worse.

 

In this vid they use REV even though something went wrong in Number 2 Engine

https://www.youtube.com/watch?v=PS1YAX70edc

 

In this vid they don't - although it is at Airbus plant so possibly during testing they may have not used it.

https://www.youtube.com/watch?v=sn7JHwRPKf4#t=68

 

In the DC-10 we taught throttles idle, max reverse, max braking, ensure ground spoilers deployed and slight forward pressure on the yoke. In the Gulfstream its basically the same. It's briefed, idle-reverse-brakes-brakes(speed brakes). Reversers are as required control permitting. If its a dry runway, I'll use max reverse engine out. If it's wet, I'll meter the reverse based on controllability. If it's icy, I'll use reverse idle. The use of reverse all depends on conditions and the reason you aborted. With icy and high crosswind conditions, reversers may aggravate the situation. During takeoff, many manufactures factor in the use of engine out reverse for accel stop distances. 

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>During takeoff, many manufactures factor in the use of engine out reverse for accel stop distances.

 

For US certification, the FAA does not allow the use reverse thrust to measure take off / stop distances. Thus, the takeoff / stop distances have a built-in safety factor because the customer flight crews will be using reverse thrust, in most cases, when they abort a take off.

 

When ever you watch the test pilots do the rejected take off testing, it's always the same, and has always been the same for many decades now, even when Lockheed and McDonnell Douglas were in the business: they load the plane to its max take off weight, make sure the brakes are well worn (not new brake pads), start the take off roll, at V1 the pilot aborts the Take off and ensure the spoilers are deployed but the pilot cannot use reverse thrust.

 

Max braking is applied and you can see the brakes turn red/white hot...the plane finally comes to a stop and must sit for 5 mins, and the fire that starts (and one usually does from the brake material) around the main gear must not reach a major structural part during that 5 min period...and if all of that happens as planned...they pass!!

 

Here is the B-777 RTO test:

 

And here is the B-747 RTO test:

http://www.boeingblogs.com/randy/archives/2011/05/back_when_i_first_started.html

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For US certification, the FAA does not allow the use reverse thrust to measure take off / stop distances.

I am in the U.S., when I flew DC-10s we would have to use reverse inop charts when one was locked out in order to calculate speeds, distances and max weight charts. This is why i made the statement. Here is a chart from my DC10 manual. Even the G550 has corrections on wet runways with a reverser locked out though it has a JAA cert.

reverse_correction.jpg

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I think your use of the word 'manufactures' threw me for a loop...you're really talking about 'operators' having and using take off distance charts with and without the use of reverser's. That makes sense.

 

Take off and stopping distances the manufacturers measure without the use of reverse thrust are for certification only.

 

:lol:

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I think your use of the word 'manufactures' threw me for a loop...you're really talking about 'operators' having and using take off distance charts with and without the use of reverser's. That makes sense.

 

Take off and stopping distances the manufacturers measure without the use of reverse thrust are for certification only.

 

:lol:

During flight testing, all of this data is collected for the purpose of creating the performance manual. The manufacturer will then deliver with the basic performance data. The operator can purchase more advanced performance data from the manufacturer for a fee. You can purchase it tabular or charted. If you think having a FAA approved performance manual containing data with and without reversers is strange, have a look at my reverser only landing distance for the G5/550. It's from the QRH. At max landing weight at SL, I can stop in 6200ft using reversers only without touching the brakes. This is great info when landing in icy conditions.

GVreverse.jpg

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Idle, or reverse? I realize if you have lost an engine you probably don't want that one in reverse in case it makes things worse.

 

In this vid they use REV even though something went wrong in Number 2 Engine

https://www.youtube.com/watch?v=PS1YAX70edc

 

In this vid they don't - although it is at Airbus plant so possibly during testing they may have not used it.

https://www.youtube.com/watch?v=sn7JHwRPKf4#t=68

In the context of this thread idle is sufficient to put the brakes in RTO mode.

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kevinh, on 27 Sept 2014 - 9:34 PM, said:

In the context of this thread idle is sufficient to put the brakes in RTO mode.

In the context of this thread, which is "how to perform a rejected takeoff" I was interested to know what the normal technique was, and really hope that if I am on an airliner that rejects the takeoff, the pilots don't think that simply reducing to idle to activate RTO autobrake is "sufficient"... I would prefer they use every last bit of negative acceleration available to them, including reverse thrust.

 

If it was the normal, airline and OEM approved, method.

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Additional comments:

 

Your speed at the time you decide to reject the take off, *must* be less than V1 (you probably already know this).

True but as far as the aircraft system is concerned you can trigger an RTO above V1. It's important to separate operational factors from system logic to avoid confusion. People might get the impression that above V1 RTO mode won't work.

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In the context of this thread, which is "how to perform a rejected takeoff" I was interested to know what the normal technique was, and really hope that if I am on an airliner that rejects the takeoff, the pilots don't think that simply reducing to idle to activate RTO autobrake is "sufficient"... I would prefer they use every last bit of negative acceleration available to them, including reverse thrust.

 

If it was the normal, airline and OEM approved, method.

I meant it was sufficient to trigger the RTO mode. The OP clearly knew how an RTO was performed but was unable to execute it in the PMDG 777.

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normal technique

 

1) announce "stop"

2) Thrust to idle

3) disconnect auto throttle

4) extend speed brakes

5) pull full reverse

6) PM calls "speed brakes up, reverse green " to confirm both reverser and speed brakes are deployed

7) PM call 70kts

8) advice ATC "call sign, Stopping"

9) stop on the Rwy, set park brake

10) deal with the problem

 

http://m.youtube.com/watch?v=C7O7R_Vk7Ko

 

Here's an example, although the rejected TO was "expected" by the captain, that was why he reacted before any engine failure indication.

 

One thing I would like to point out, pulling reverse on the 777 will shorten the stopping distances. Unlike other autobrake mode which is based on rate of deceleration, RTO autobrake always applies maximum braking like if you depress the brakes fully. Therefore using full reverse will have an effect on the stopping distance.

 

The use of speed brake will also help to dump the loft making the brakes more effective.

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>If it was the normal, airline and OEM approved, method.

 

There will be differences in how each pilot stops his or her a/c when doing an RTO. Many carriers do not follow the manufacturer guidelines. In fact, with my experience with working in flight crew training with all three of the US manufacturers at one time or another (Lockheed, McDonnell Douglas and Boeing) about 70% to 80% do not use the QRH as published by the manufacturer. Most of them will write their own procedures based on their aircraft fleet for pilot standardization.

 

For example, the big one is engine fires. Very few carriers shut down an engine for fire the way the manufacturer QRH recommends. They do it their own way, based on their a/c fleet. So, where possible, the pilots shut down an engine for fire one way regardless of what plane they are flying that month.

 

So, I don't think there is a 'normal' way to do an RTO in this case. Even when there is a company policy on how to do an RTO, the Captain may over ride that, based on his or her experience and do something slightly different because of the current conditions.

 

I read somewhere years ago a good guide on using reverse thrust with an engine-out RTO:

 

-on a dry runway, use full reverse on the remaining engine, you'll have enough friction to keep the nose going straight down the runway and get your maximum stopping capability.

-on a wet runway use half reverse (remember to land very firmly on the wet runway to plant the wheels for braking action to prevent hydroplaning. You don't want to be making a smooooooth landing on a wet runway. Land firmly.)

-on an icy runway use idle reverse.

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>If it was the normal, airline and OEM approved, method.

 

There will be differences in how each pilot stops his or her a/c when doing an RTO. Many carriers do not follow the manufacturer guidelines. In fact, with my experience with working in flight crew training with all three of the US manufacturers at one time or another (Lockheed, McDonnell Douglas and Boeing) about 70% to 80% do not use the QRH as published by the manufacturer. Most of them will write their own procedures based on their aircraft fleet for pilot standardization.

 

For example, the big one is engine fires. Very few carriers shut down an engine for fire the way the manufacturer QRH recommends. They do it their own way, based on their a/c fleet. So, where possible, the pilots shut down an engine for fire one way regardless of what plane they are flying that month.

 

So, I don't think there is a 'normal' way to do an RTO in this case. Even when there is a company policy on how to do an RTO, the Captain may over ride that, based on his or her experience and do something slightly different because of the current conditions.

 

I read somewhere years ago a good guide on using reverse thrust with an engine-out RTO:

 

-on a dry runway, use full reverse on the remaining engine, you'll have enough friction to keep the nose going straight down the runway and get your maximum stopping capability.

-on a wet runway use half reverse (remember to land very firmly on the wet runway to plant the wheels for braking action to prevent hydroplaning. You don't want to be making a smooooooth landing on a wet runway. Land firmly.)

-on an icy runway use idle reverse.

The only caveat  is the 6158 and type check. During the type check or 6158 recurring, you are required to operate the aircraft in accordance with the manufacturer's FAA approved recommendations from the AFM. As a minimum, AFM procedures must satisfy requirements of part 25. For example the engine fire example you gave, the minimum alt for thrust reduction is 400ft. This is why many takeoff briefs contain the phrase "no thrust reducing bold face below 400ft". My caveat to that is a deployed reverser above V1. If I'm having adverse yaw, I'll direct the PM to shut it down. I place the letting it burn attitude in the same category of V2. If I have V2+15 at engine failure, why sacrafice the 15 kts for V2. If the engine is producing thrust while burning, why immediately shut it down after 400ft. In the 5 type of jets I've been  qualed in, we had our company specific normal procedures but we adhered to all of the manufacturer's bold face, CAPs, emergency and abnormal procedures. In the 5/550, we have our own company checklist and refer to the QRH for emergency/abnormal procedures and CAS messages. By the way, part 25 states that accel stop distances with reverse thrust is certifiable on wet runways. :drinks: 

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Hello,

my question might sound a bit stupid but I could not find anything about this topic on the net.

After already in take off mode, I tried to reject the take off by just pulling back the throttles at my joystick but the aircraft continued to accelerate for take off.

What do I need to do to reject the take off?

I would be very thankful if you could help me here.

 

Thanks very much in advance.

 

Tilo

You marked Kyles answere as the best answere.....but it is really only part of the answere!

 

The best answere (a summary of the proper QRH procedure) has been given in this thread later on though.

This procedure can be found in the Maneuvers chapter on page MAN 1.2 of the PMDG777 QRH (all the way at the end, page 790 of 844 according my iPad).

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You marked Kyles answere as the best answere.....but it is really only part of the answere!

 

The best answere (a summary of the proper QRH procedure) has been given in this thread later on though.

This procedure can be found in the Maneuvers chapter on page MAN 1.2 of the PMDG777 QRH (all the way at the end, page 790 of 844 according my iPad).

 

Sure, but his base issue was that his throttle override setting wasn't set to the right setting.

 

So, regardless of whatever followed to expand on my very basic answer, none of them would've worked without what I'd written.  He was looking for how to get the procedure to work with the software, and not necessarily how to do it.  The only reason I threw the "steps" in there was to illustrate that that's all that's required to get the software to reject.  The rest of the SOP-based steps are irrelevant to the original question, though they're extremely helpful for understanding the actual procedure.

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Sure, but his base issue was that his throttle override setting wasn't set to the right setting.

 

So, regardless of whatever followed to expand on my very basic answer, none of them would've worked without what I'd written.  He was looking for how to get the procedure to work with the software, and not necessarily how to do it.  The only reason I threw the "steps" in there was to illustrate that that's all that's required to get the software to reject.  The rest of the SOP-based steps are irrelevant to the original question, though they're extremely helpful for understanding the actual procedure.

I guess you are right.....more so since the OP never even bothered to look back at all the additional info people were trying to give.

 

The "what followed after" part had me believing he was asking about the SOPs as well.

 

And the part that followed only followed because the second part of your answere was so compressed.

 

If you would have just said:

"Ensure your A/T setting in the PMDG SETUP menus is set to allow the hardware to override in HOLD/ARM MODE. Sounds like the sim is just ignoring your hardware."

then your answere woukd have completely correct.

 

When you added:

"The steps for rejecting throttle are as follows:

Pull throttles back to idle

Done

(Provided your autobrake is set to RTO)"

your answere became or seemed to become (whatever) incomplete.

Which is why others where trying to explain that there is a lot more to rejecting a take off than "Pullback throttle and done".

I know you know that.....but not everybody does.....so I think it is good that things were expanded a bit.

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Which is why others where trying to explain that there is a lot more to rejecting a take off than "Pullback throttle and done".
I know you know that.....but not everybody does.....so I think it is good that things were expanded a bit.

 

Fair assessment.

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