B777 abort takeoff procedure
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B777 abort takeoff procedure
B777, when reject takeoff what is your company precedure?THR lever idle -speedbrake up then reverse or THR lever idle then select THR reversers to get auto speedbrake? Thanks!!
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Mr. Boeing still stands by thrust levers to idle, and manually deploy the speedbrakes and then the thrust reversers. Don't rely on the automation during that critical phase.
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At Emirates Habibi we have just deleted the requirement to manually raise the Speedbrakes during an RTO on the 777. PNF monitors the speedbrake deployment. Been a long time coming this change.
Follow your companies SOP's however is my advice
SyB
Follow your companies SOP's however is my advice
SyB
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Manually deploy the speedbrakes before using the reversers. There was a time when the automation was approved for individual airlines, but that is NO MORE. Speedbrakes first, reversers second...exceptions.
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That is very intersting as that would require a NTO or No Technical Objection from Boeing
. Not likely but I don't doubt your word just that it is contrary to current Boeing policy. As you have said, follow your company procedures. The Boeing FCTM does not address your methodology.
. Not likely but I don't doubt your word just that it is contrary to current Boeing policy. As you have said, follow your company procedures. The Boeing FCTM does not address your methodology.
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Sorry for the triple posting but I did a little research on this subject and have learned that this devaition is unique to the 777 and has to do with Boeing's 787/777 common type rating quest. More details to follow and I believe that ANZ may also have adopted this procedure. Maybe one of their pilots could confirm?
Can't speak for the 777 but on our 756 fleet our reject procedure is :
Throttles-idle, disconnect autothrottles (activates RTO maximum available braking above 80 knots)
Reverse-to interlock then full reverse (interlock will deploy all available spoilers)
This sequence of actions provides for the most rapid application in the most efficient sequence of all deceleration devices.
If, of course on pulling the throttles to idle RTO brakes do not engage (and this is a required call out for us) then manual braking must be used, you are far better off, however letting the RTO function provide RELENTLESS maximum braking to a stop while you keep it straight.
Similarly if deploying reverse does not activate spoilers you can rapidly pull the lever yourself.
Stick with the automatics for max stopping and override if one or more does not function.
Throttles-idle, disconnect autothrottles (activates RTO maximum available braking above 80 knots)
Reverse-to interlock then full reverse (interlock will deploy all available spoilers)
This sequence of actions provides for the most rapid application in the most efficient sequence of all deceleration devices.
If, of course on pulling the throttles to idle RTO brakes do not engage (and this is a required call out for us) then manual braking must be used, you are far better off, however letting the RTO function provide RELENTLESS maximum braking to a stop while you keep it straight.
Similarly if deploying reverse does not activate spoilers you can rapidly pull the lever yourself.
Stick with the automatics for max stopping and override if one or more does not function.
Last edited by stilton; 2nd Sep 2009 at 23:25.
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On our triples:
HP simultaneously & rapidly disconnects autothrottle, closes thrust levers & applies max braking (or verify correct operation of RTO)
NHP selects both reverse thrust levers to interlock, VERIFIES speedbrakes have deployed automatically, if not, deploy manually, then apply max reverse thrust.
HTH
HP simultaneously & rapidly disconnects autothrottle, closes thrust levers & applies max braking (or verify correct operation of RTO)
NHP selects both reverse thrust levers to interlock, VERIFIES speedbrakes have deployed automatically, if not, deploy manually, then apply max reverse thrust.
HTH
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Thanks to all the answers. To use reversers is not part of the certification. That is why Boeing FCTM use manual spoilers after thrust levers idle. Boeing did not answer whether we can use auto function of the spoilers by raising the thrust levers.
Having experienced several RTO's, one of which was from near V1, I cannot emphasis enough how important the Speedbrake is!
The lift generated by the wings at high speed is enormous. The aircraft is literally ready to fly!
Without the weight back on the wheels, the brakes are useless!
The lift generated by the wings at high speed is enormous. The aircraft is literally ready to fly!
Without the weight back on the wheels, the brakes are useless!
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When reversers are selected, the spdbrk lever will go (mechanically) in the arm position then immediately autospeedbrakes takes over and deploys them. Can autospdbreaks fail? Yes. Can they fail at the same time as an engine fire or failure (or serious event) during take-off at high speeds? Of course not. Only in the simulator... and the simulator has this failure available not with the intent of combining it with an RTO.
Last edited by stormyweathers; 11th Aug 2011 at 19:04.
Not having flown anything but the 737 variants I cannot comment on the 777.
The 737 FCTM makes it crystal clear that assuming RTO is serviceable, the first action after closing the thrust levers is to manually apply the speed brake lever to up. As some one mentioned earlier, the importance of prompt speed brake operation cannot be overestimated - especially on a contaminated runway.
The speed brake is on the captain's side of the throttle quadrant and it is therefore logical that he operates the speed brake as he will be the handling pilot in an abort. It is cack-handed to have the copilot responsible for operating the speed brake because he has to reach far over the captains hands to get a grip on the speed brake lever. Every second delay in applying speed brake extends the abort distance.
The auto-speed brake operation in the 737 is actuated by the first selection of the reverse thrust levers. That means providing the captain selects the reverse levers asap, there is little difference in time between auto-speed brake actuation and manual speed brake actuation.
That said, auto-actuation of the speed brakes have been known to fail without prior warning. Which is precisely the reason why this failure mode is available on the simulator instructor panel.
Boeing foresaw this possibility and that is why they advise the speed brake should always be selected manually in an abort rather than blindly rely on the automatic function. The beauty of this is another Boeing feature and that is if the captain forgets to select the speed brake manually the auto-extension serves as the fall-back position providing of course reverse thrust is selected. Fail safe as it were.
If the crew rely solely on the auto-speed brake function and it fails to actuate on reverse thrust lever selection, experience has shown it takes a couple of seconds to realise the speed brake lever has failed to come up automatically. By the time someone gets his hand on the speed brake lever to pull it manually, vital lift dumping is delayed and the abort (or landing) distance is extended.
The 737 FCTM makes it crystal clear that assuming RTO is serviceable, the first action after closing the thrust levers is to manually apply the speed brake lever to up. As some one mentioned earlier, the importance of prompt speed brake operation cannot be overestimated - especially on a contaminated runway.
The speed brake is on the captain's side of the throttle quadrant and it is therefore logical that he operates the speed brake as he will be the handling pilot in an abort. It is cack-handed to have the copilot responsible for operating the speed brake because he has to reach far over the captains hands to get a grip on the speed brake lever. Every second delay in applying speed brake extends the abort distance.
The auto-speed brake operation in the 737 is actuated by the first selection of the reverse thrust levers. That means providing the captain selects the reverse levers asap, there is little difference in time between auto-speed brake actuation and manual speed brake actuation.
That said, auto-actuation of the speed brakes have been known to fail without prior warning. Which is precisely the reason why this failure mode is available on the simulator instructor panel.
Boeing foresaw this possibility and that is why they advise the speed brake should always be selected manually in an abort rather than blindly rely on the automatic function. The beauty of this is another Boeing feature and that is if the captain forgets to select the speed brake manually the auto-extension serves as the fall-back position providing of course reverse thrust is selected. Fail safe as it were.
If the crew rely solely on the auto-speed brake function and it fails to actuate on reverse thrust lever selection, experience has shown it takes a couple of seconds to realise the speed brake lever has failed to come up automatically. By the time someone gets his hand on the speed brake lever to pull it manually, vital lift dumping is delayed and the abort (or landing) distance is extended.
Last edited by Centaurus; 10th Aug 2011 at 08:46.
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The lift generated by the wings at high speed is enormous. The aircraft is literally ready to fly!
Really? The wing generates no lift at all until it is rotated to a positive angle relative to the airflow, something it is most certainly not doing with the nosewheel on the ground. The reason the speed-brake should be deployed rapidly is to prevent the aircraft from accelerating further, simply acting as air brakes. There will be little or no reduction on wheel loading until such time as the aircraft has been rotated and is almost airborne; only then do the oloes extend from the normal, squat position.
If you doubt the truth of this, sit at a seat over the wing of a 777 or A330 and watch carefully as the wing flexes upwards only when the nose is about 4-6 degrees above the horizon during rotation. Further evidence on humid days is visible by the fact that there are no wing-tip contrails until the same angle of attack. The wing is definitely not producing any lift prior to this moment.
Happy Landings.
Really? The wing generates no lift at all until it is rotated to a positive angle relative to the airflow, something it is most certainly not doing with the nosewheel on the ground. The reason the speed-brake should be deployed rapidly is to prevent the aircraft from accelerating further, simply acting as air brakes. There will be little or no reduction on wheel loading until such time as the aircraft has been rotated and is almost airborne; only then do the oloes extend from the normal, squat position.
If you doubt the truth of this, sit at a seat over the wing of a 777 or A330 and watch carefully as the wing flexes upwards only when the nose is about 4-6 degrees above the horizon during rotation. Further evidence on humid days is visible by the fact that there are no wing-tip contrails until the same angle of attack. The wing is definitely not producing any lift prior to this moment.
Happy Landings.
Rubik, most aerofoils are not symmetrical, and therefore produce some lift, even at 0° AoA. This is why speedbrakes are used to disrupt the airflow over the top of the wing and destroy lift. This scenario ensures that maximum weight is on the wheels, allowing the brakes to work as effectively as possible.
Wings are able to produce lift even if they are not producing any contrails at all...
Another way of looking at it is with a GA aircraft, if the pilot does not rotate at all, there will come a speed at which the aircraft will lift off anyway. It's no different for the B777 or any transport category aircraft, except you'd probably find you are off the end of the runway before you can observe this.
Wings are able to produce lift even if they are not producing any contrails at all...
Another way of looking at it is with a GA aircraft, if the pilot does not rotate at all, there will come a speed at which the aircraft will lift off anyway. It's no different for the B777 or any transport category aircraft, except you'd probably find you are off the end of the runway before you can observe this.