Speedbrakes upon RTO

[Budbud 227]

Joe diamond, after a full stop after an abort before V1 do you set the parking brake (captain) and the FO sets flaps 40 when stopped? My SOPs call for this!

 

 

What is the reason behind flaps 40? Is it for evacuation purpose?

[Driver170 42]

At this point when you stop, the captain sets the parking brake and FO sets flaps 40. Its in my SOP. I think its to prepar for an evacuation! So if you had to you wouldn't need to wait till the flaps have gone down to 40

[scandinavian13 5,192]

What is the reason behind flaps 40? Is it for evacuation purpose?

 

Yeah, it's a backup. In case a slide fails, you can, in theory, slide down the extended flap. 

[Budbud 227]

Great! Thanks for the explanation.

[JoeDiamond 67]

Joe diamond, after a full stop after an abort before V1 do you set the parking brake (captain) and the FO sets flaps 40 when stopped? My SOPs call for this!

 

That would depend on why you aborted in the first place.  If you thought an evacuation was a possibility then yes, but it's not something we would do by rote every time we abort a takeoff.

[downscc 1,327]

A few years back, I took a ride on a B737-700 (then it was Continental) KSNA to PHOG and that small chance of a RTO at SNA was pretty big on my mind. Wow.

[JoeDiamond 67]

Yeah, it's a backup. In case a slide fails, you can, in theory, slide down the extended flap. 

 

It's not really what I would consider a backup.  It's the only way down from the overwing exits.  No slides for those.

[BlueStar 323]

I don't do high speed aborts, if I'm even close to V1 I'm go'n.   

 

blaustern

[19dcavscout 39]

I don't do high speed aborts, if I'm even close to V1 I'm go'n.   

 

blaustern

 

Seriously? In the sim or real life? V1 is predicated on having the available runway distance available to conduct and ACCEL-STOP.  Anything before that and you may not be able to accelerate enough to properly clear the required obstacles at the end of the runway. With that thinking, you should almost always go regardless. V1 is my cutoff. When taking off, unless I hear "V1, rotate" (In the aircraft I fly, V1 and Vr happen to be the same speed but that doesn't matter) I am stopping. I am continuously thinking in my mind abort abort abort and only when I hear those magic words (V1, Rotate) my right hand comes off the throttle on onto the yoke so there is no accidental reduction in power.

 

The FAA defines V1 as: The US Federal Aviation Administration defines it as: "the maximum speed in the takeoff at which the pilot must take the first action (e.g., apply brakes, reduce thrust, deploy speed brakes) to stop the airplane within the accelerate-stop distance. V1 also means the minimum speed in the takeoff, following a failure of the critical engine at VEF, at which the pilot can continue the takeoff and achieve the required height above the takeoff surface within the takeoff distance."

[Jack C 8]

Yes, just remember, IRL, every decision you make prior to an incident or accident will be scrutinized by lawyers. Do what you're trained to do

 

Jack Colwill

[JoeDiamond 67]

Yes, just remember, IRL, every decision you make prior to an incident or accident will be scrutinized by lawyers. Do what you're trained to do

 

Jack Colwill

 

But his way is better.  :eyeroll:

[BlueStar 323]

As the aircraft approaches V1 the successful completion of an RTO becomes increasing more difficult. 

 

If you wait until V1 to initiate a RTO, then by definition, there may not be sufficient runway remaining to successfully complete the maneuver.

 

My experience has been it takes at a minimum of two seconds to get the aircraft to the point where it has started to decelerate.  In that two seconds the aircraft could have easily accelerated as much as 10 to 15 knots and be well past V1 and Vref. 

 

The pilots doing the aircraft certification knew when the RTO was going to start and they are among the best in the business.    I'm not that good, but maybe some of you are. :smile:

 

blaustern

[19dcavscout 39]

As the aircraft approaches V1 the successful completion of an RTO becomes increasing more difficult. 

 

If you wait until V1 to initiate a RTO, then by definition, there may not be sufficient runway remaining to successfully complete the maneuver.

 

My experience has been it takes at a minimum of two seconds to get the aircraft to the point where it has started to decelerate.  In that two seconds the aircraft could have easily accelerated as much as 10 to 15 knots and be well past V1 and Vref. 

 

The pilots doing the aircraft certification knew when the RTO was going to start and they are among the best in the business.    I'm not that good, but maybe some of you are. :smile:

 

blaustern

True, however, the FAA has required the manufactuers to factor in additional time for the average pilot when conducting these:  

 

"2.3.2.2 Airplane Flight Manual Transition Times: Although the line pilot must be prepared for an RTO during every takeoff, it is fairly likely that the event or failure prompting the Go/No Go decision will be much less clear-cut than an outright engine failure. It may therefore be unrealistic to expect the average line pilot to perform the transition in aslittle as one second in an operational environment. Human factors literature describes the line pilot’s job as a “complex task” since the pilot does not know when an RTO will occur. In consideration of this “complex task”, the flight test transition times are increased to calculate the certified accelerate-stop distances specified in the AFM. These additional time increments are not SECTION 2 2.12 intended to allow extra time for making the “Go/No Go” decision after passing V1. Their purpose is to allow sufficient time (and distance) for “the average pilot” to transition from the takeoff mode to the stopping mode." 

 

Here is the link to the source: https://www.faa.gov/other_visit/aviation_industry/airline_operators/training/media/takeoff_safety.pdf

 

Essentially they factor in an additional 2 seconds of the time required for the RTO to be in full effect.  This means if the incident happened at 120 and your V1 is 121 (so it has happened before V1), the ACCEL-STOP distances that has been published has already factored that you will continue your speed beyond 121 before you start slowing down. I hope that makes sense.

I forgot to add this part as well:

 

"Regardless of the method used, the accelerate stop distance calculated for every take off from the AFM is typically 400 to 600 feet longer than the flight test accelerate-stop distance."

 

That should give you some additional buffer.

[kevinh 409]

As the aircraft approaches V1 the successful completion of an RTO becomes increasing more difficult.

 

If you wait until V1 to initiate a RTO, then by definition, there may not be sufficient runway remaining to successfully complete the maneuver.

 

My experience has been it takes at a minimum of two seconds to get the aircraft to the point where it has started to decelerate. In that two seconds the aircraft could have easily accelerated as much as 10 to 15 knots and be well past V1 and Vref.

 

The pilots doing the aircraft certification knew when the RTO was going to start and they are among the best in the business. I'm not that good, but maybe some of you are. :smile:

 

blaustern

The aircraft is decelerating as soon as you pull the thrust levers back. How long does that take? The speed may well peak above V1 but that doesn't matter. V1 is the decision speed, not a maximum which if exceeded you must take off.

[Jetstream96 20]

Seriously? In the sim or real life? V1 is predicated on having the available runway distance available to conduct and ACCEL-STOP.  Anything before that and you may not be able to accelerate enough to properly clear the required obstacles at the end of the runway.

You may prefer continuing the takeoff to making a high speed RTO, if it's only an pack failure.