B777 abort takeoff procedure
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Capt. Fathom, so if we dont use the speed brake the distance to stop would increase significantly? Rubiks is making me think twice about whether significant lift is generated during TO roll. For landing of course it is extremely important. But for TO, the wings are made for high speed flight and is not so curved as mentioned. I think they might not be so critical that you must absolutely deploy them within a fraction of a second. The airplane weighs 300T and the weight is not on the wheels?? Just wandering if numbers are available for RTO with or without spdbrakes.
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I am sure there are numbers in "Mr. Boeings" draw but not accessable to us.
Our Company uses the conservative method as well: RTO = Thrust Lever close, A/T disconnect, monitor AB, Speed brake Lever manualy deploy, then use Reverse and stop the Airplane on the paved surface. The F/O notifies the Tower and then we evaluate the situation what further action is needed.
I hope that helps. Hopefully eager Chief Pilots are clever enough to reinforce to follow Boeings proceedures closely. In case one of his troopers rests the Airplane after an RTO in the mud the BIG question will be: Who´s fault is it? and if there is a deviation from recommended proceedures then the Insurance Company is asking uncomfortable questions and the head of accounting starts to sweat....
Fly safe and land happy
NG
Our Company uses the conservative method as well: RTO = Thrust Lever close, A/T disconnect, monitor AB, Speed brake Lever manualy deploy, then use Reverse and stop the Airplane on the paved surface. The F/O notifies the Tower and then we evaluate the situation what further action is needed.
I hope that helps. Hopefully eager Chief Pilots are clever enough to reinforce to follow Boeings proceedures closely. In case one of his troopers rests the Airplane after an RTO in the mud the BIG question will be: Who´s fault is it? and if there is a deviation from recommended proceedures then the Insurance Company is asking uncomfortable questions and the head of accounting starts to sweat....
Fly safe and land happy
NG
The lift generated by the wings at high speed is enormous. The aircraft is literally ready to fly!
On the ground,Speed brakes are more about producing drag than killing lift.
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DESCRIPTION:
Model: 777
Series/Product: 16 - FCOM/QRH - Flight Crew
Boeing Response
For a rejected takeoff and as it is described today in B777 QRH, the speedbrakes lever has to be manually activated before the thrust reversers are used, instead of relying on the auto speedbrakes extension system. This is not instinctive since for each landing the reversers are used first and speedbrakes activation is triggered by the reversers. In a high stress situation it is very likely that the crew would react as he is doing all the time.
We would like to get a NTO from Boeing allowing **** to use reversers in first place during a RTO. This would allow the company to have a consistent procedure for all models even with the B787 coming procedure.
RESPONSE:
The RTO procedure as currently published in the FCOM was validated and approved by the FAA during the certification of each model. However, the FAA has agreed to the use of the reverse thrust levers to automatically deploy speedbrakes during an RTO maneuver on the 777. For the 777, the FAA has agreed that analyses and flight experience indicate that if the procedure is accomplished correctly, automatic deployment of the speedbrakes by positioning the reverse thrust levers for reverse thrust is equivalent in effectiveness to the manual deployment of the speedbrakes.
Therefore, Boeing has no technical objection to using the reverse thrust levers to automatically deploy speedbrakes during the RTO maneuver on the 777 provided the following conditions are met:
1. The pilot doing the RTO positions all reverse thrust levers to the idle position, then applies reverse thrust as needed.
2. The pilot monitoring observes the speedbrake lever to ensure it moves to the UP detent upon application of reverse thrust.
3. The pilot monitoring calls "SPEEDBRAKES UP" or "SPEEDBRAKES NOT UP" for all RTO maneuvers and landings. Making these callouts for all landings will help to ensure the habit pattern of these callouts becomes established.
4. If automatic deployment does not occur, one of the pilots takes immediate action to manually move the speedbrake lever to up.
5. The operator's training program must emphasize the criticality of speedbrake extension to the RTO maneuver and simulator training programs must include practice in responding to failure of speedbrakes to automatically deploy. Pilots must understand that the deployment of the speedbrakes in conjunction with maximum effort braking constitutes the large majority of the stopping effort. Reverse thrust credit is not considered during certification for takeoff distance calculation.
6. The operator obtains local regulatory approval for the revised procedure.
This issue has been considered in the design of the EEC software on the 777. The 777 EEC is programmed to slightly delay thrust reverser deployment when the reverse thrust levers are pulled. This EEC feature makes an RTO procedure that uses the reverse thrust levers to deploy speedbrakes equivalent to the current RTO procedure of manual speedbrake extension prior to applying reverse thrust.
Model: 777
Series/Product: 16 - FCOM/QRH - Flight Crew
Boeing Response
For a rejected takeoff and as it is described today in B777 QRH, the speedbrakes lever has to be manually activated before the thrust reversers are used, instead of relying on the auto speedbrakes extension system. This is not instinctive since for each landing the reversers are used first and speedbrakes activation is triggered by the reversers. In a high stress situation it is very likely that the crew would react as he is doing all the time.
We would like to get a NTO from Boeing allowing **** to use reversers in first place during a RTO. This would allow the company to have a consistent procedure for all models even with the B787 coming procedure.
RESPONSE:
The RTO procedure as currently published in the FCOM was validated and approved by the FAA during the certification of each model. However, the FAA has agreed to the use of the reverse thrust levers to automatically deploy speedbrakes during an RTO maneuver on the 777. For the 777, the FAA has agreed that analyses and flight experience indicate that if the procedure is accomplished correctly, automatic deployment of the speedbrakes by positioning the reverse thrust levers for reverse thrust is equivalent in effectiveness to the manual deployment of the speedbrakes.
Therefore, Boeing has no technical objection to using the reverse thrust levers to automatically deploy speedbrakes during the RTO maneuver on the 777 provided the following conditions are met:
1. The pilot doing the RTO positions all reverse thrust levers to the idle position, then applies reverse thrust as needed.
2. The pilot monitoring observes the speedbrake lever to ensure it moves to the UP detent upon application of reverse thrust.
3. The pilot monitoring calls "SPEEDBRAKES UP" or "SPEEDBRAKES NOT UP" for all RTO maneuvers and landings. Making these callouts for all landings will help to ensure the habit pattern of these callouts becomes established.
4. If automatic deployment does not occur, one of the pilots takes immediate action to manually move the speedbrake lever to up.
5. The operator's training program must emphasize the criticality of speedbrake extension to the RTO maneuver and simulator training programs must include practice in responding to failure of speedbrakes to automatically deploy. Pilots must understand that the deployment of the speedbrakes in conjunction with maximum effort braking constitutes the large majority of the stopping effort. Reverse thrust credit is not considered during certification for takeoff distance calculation.
6. The operator obtains local regulatory approval for the revised procedure.
This issue has been considered in the design of the EEC software on the 777. The 777 EEC is programmed to slightly delay thrust reverser deployment when the reverse thrust levers are pulled. This EEC feature makes an RTO procedure that uses the reverse thrust levers to deploy speedbrakes equivalent to the current RTO procedure of manual speedbrake extension prior to applying reverse thrust.
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@sow thanks for your excellent explanation
... just to be precise... in all second generation Boeing airplanes ...
during landing ... if in ARM position the speedbrake lever is driven aft to the up position when both Thrust Levers at idle and the main landing gear is fully on ground (not tilted)...
... on the ground when either reverse thrust lever is moved to reverse idle detent, the speedbrake automatically extend. The speedbrake lever does NOT need to be in the ARMED position.
Automatic speedbrake are NOT available in the secondary and direct modes. This is why in some old 777 QRH it's possible to find manual speedbrake deployment required on RTO ....
each landing the reversers are used first and speedbrakes activation is triggered by the reversers.
during landing ... if in ARM position the speedbrake lever is driven aft to the up position when both Thrust Levers at idle and the main landing gear is fully on ground (not tilted)...
... on the ground when either reverse thrust lever is moved to reverse idle detent, the speedbrake automatically extend. The speedbrake lever does NOT need to be in the ARMED position.
Automatic speedbrake are NOT available in the secondary and direct modes. This is why in some old 777 QRH it's possible to find manual speedbrake deployment required on RTO ....
Last edited by Non Zero; 14th Aug 2011 at 14:05.
Boeing covers their rear-end by having a defined sequence during the RTO, I'm sure there is vetting/input by legal experts to make sure that by following the company procedure there is little risk of litigation if an over-run accident occurs....I have used The Normal Boeing Procedure on The 777 with three operators now and previously on the 767.
