Hey 777 experts out there,

 

I was just wondering about the procedure for rejected takeoffs, with regard to the speedbrakes.

 

Found this video of an RTO in a 777 Sim on youtube. At 1:11 an engine failure occurs and the captain does the following:

 

1. pull the thrust levers back to idle

2. deploy the speedbrakes

3. set reverse thrust.

 

That's also how it's written in the QRH.

 

But now I coincidentally found that on the PMDG 777, as soon as you pull the reverser levers, the speedbrake will automatically open.

 

So now I'm wondering whether this is the real airplane's behaviour (and since it is PMDG, I believe it is :wink:) and why do you first manually set the speedbrakes and then the reverse thrust, when the speedbrake would automatically deploy on activating the reverser???

 

Maybe anyone can shed a bit of light on this?

 

Best regards

Olli

Hi , For what i know when u selct RTO the speed brakes automatically deploy when reverse are on...

Reverse is not factored into the RTO during certification.   Anyway, what you are seeing is pretty unique to the 777.  Spoilers first than Rev thrust.

 

Spoilers will auto deploy when rev thrust is selected however they could fail. Most SOPS want you to apply manual spoilers and then apply rev thrust.

 

 

.

Regards

Although the speedbrakes will come up with the reversers, you're also required to physically pull the speedbrakes in case they fail to deploy.

Throttles to idle, this will engage RTO wheel brakes, while the engines spool down to idle, pull spoiler handle all the way back, then pull the reverser handles all the way up, if appropriate.. Of course this is all done in a few seconds. What I am not sure on is when NOT to use reverse, EG if engine is on fire..?

I fly Embraer 190 and in an RTO as soon as you pull back the thrust levers the spoilers deploy automatically same was on CRJ Series 100-900. Activating the spoilers by hand i would say it is just a back up procedure in case they are not deploying. This works only if autobrake is set to RTO (Embraer). Think Boeing and Airbus work the same.

 

As far as an engine fire during take off roll you can deploy the reverser. In case of a severe damage due to rotor burst or a heavy bird strike hmmm the reverser wouldnt work properly anyway therefore there will be an asymetric force into the direction of the good engine and the chance of an runway excursion is likely. But as we all trained to figure that out what just happened in an RTO is very unlikely. The goal is to stop that plane on the ground and to prepare it for an evac if required.

 

So if you want to operate the PMDG 777 as close as possible to reality i think you gotta stick to the SOPs of Boeing.

Boeing's used to confuse me since you had to arm the spoilers for takeoff in the Airbus, always got confused as to whether its completely manual or automatic when you retard the throttles. 

Airbus  A320 -  RTO spoiler logic

 

1. Spoliers are armed
2. Aircraft ground speed is above 72 kts.
3. Thrust levers are brought back to idle.

 

You only get partial spoilers if you attempt to deploy them manually

 

Boeing 777 - No need to arm the spoilers, pretty sure the logic is 60kts or above everything is automatic once rev thrust is selected