MOM

Thursday, April 7, 2011

A330 Thrust Levers

"Non-moving" thrust levers took some getting used to when transitioning from the Boeing to the Airbus.

Well, they move... but not in direct proportion to the power with auto-thrust engaged. With manual thrust, they are just like any normal thrust lever. Push up for more power, pull back for less.

But when the autothrust is active the levers don't move. We place them in one of the four positions for power available "up to" that selected setting.


The four positions:
  1. 0 ... Idle.
  2. CL ... Climb.
  3. FLX MCT ... Flex and Max Continuous
  4. TOGA ... Takeoff and Go-around
Setting power for takeoff is easy. If we plan to use full power for departure we set the thrust levers at TOGA. If we plan to use a flex temperature for departure...which is nothing more than a reduced power setting... we set FLX. After takeoff, at Thrust Reduction Height, we'll pull the thrust levers back to CL.

They stay in the Climb position for the remainder of the flight until landing. Yes, even on approach. Conceptually it feels weird to have a Climb Power setting for arrival and approach. What we need to remember is that in the CL position power is available "up to" climb power. Whatever the plane needs for a given speed or power setting.

So we fly the entire trip in CL. Unless of course we lose an engine, then we take our operating engine to MCT. This enables power on the good engine anywhere from idle up to max continuous.


The red button is the autothrust disconnect pushbutton. But before we push that button it's important to pull the thrust levers back to match them with the actual power setting... noted on the EPR indicator.

If you don't pull the thrust levers back and match the power before disconnecting the autothrust, the thrust will increase to full climb power... the position of the thrust levers. This can get a little crazy if you're on approach when the power is lower and you inadvertently press that button and the power screams forward. If that happens, pull the thrust levers back and control it. Not a big deal. Just be prepared and respond.

A quick way to disconnect the autothrust is also to pull the levers to the 0 position, or idle. When they touch idle you have control of the thrust. Bounce them off idle and bring them back up, you have control manually. Quick and easy.

There is not a lot of mystery about these thrust levers. Initially I thought I would miss their movement as they found their way into my peripheral vision. But... really, it's not so bad. Just different.

Enjoy the journey!

~ Karlene

33 comments:

  1. Keeping all those details in mind, being prepared and responding seems key in transitioning from learned systems to new ones. I can see why the industry puts so much emphasis on simulator training--that's smart!

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  2. Thanks Linda. The not-so-funny thing is, that Boeing has autopilot disconnect switches on the thrust levers. So, Boeing guys... being tired and defaulting to old habit patterns sometimes hit that little red button by accident when they are on approach and want to disconnect the autopilot. Then they get a big surprise.

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  3. Ok, good to know. When we go up in a 172, I'll have to make sure you do pull the power back from cruise when landing. Move the throttle Karlene, it's fly by "cable" not "wire" in this plane!

    Ha! ;-)

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  4. I love cables!!! Except connected to my internet. Wire is the way to go there.

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  5. Great blog again Karlene. It must feel very weird not to feel the movement of the levers...then again it must be weird to lose the control column too. Do Bus pilots suffer when converting to Boeing ?

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  6. Thanks for the comment Munawar. Yes, it is weird to lose the controls between our legs too. Yes, we suffer converting. But that's called change. I hear it's a good thing. Change that is... not suffering.

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  7. if pilots receive a reroute and get a new flight plan, do they use this new plan as the master document, or do they use the original one and write the new numbers in?

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  8. If we were to get a reroute over the ocean with a significant change of altitude and course... we would notify Dispatch and they would send us new numbers. (Fuel and time estimates)But normally a reroute in Class I airspace, we just type it into the MCDU and fly it.

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  9. what about track and distance numbers?

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  10. Anonymous... what do you mean by track and distance numbers?

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  11. sorry I mean the headings to each waypoint and the distances between the waypoints

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  12. Nope, we don't. All that has been verified prior to flight when we load the flight plan. Enroute we confirm we are flying between those points. We write down time, and fuel remaining.

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  13. What A Wonderful Post! As A Niece, Of Uncle Jack & Aunt Winnie,That is some wonderful info... that I can tuck away... & share with my children!!! Thank You!! Will Pay It Forward!!

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  14. I want to say THANK YOU for these blogs on the Sallee family. Jack was my Uncle, my mother's only brother, so Andy, Joe, Willy and Mike are my cousins. It is very interesting to read about them and their accomplishments. They are a good group of guys, and I know Uncle Jack would be immensly proud that all his hard work has paid off so well. Again, thank you.

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  15. when flying over the north atlantic, is it normal to receive route shortcuts?

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  16. thanks. do pilots also have to make mid point checks when flying over the atlantic, where they record the wind and temperature midway between waypoints and then send this data to ATC?

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  17. Great explanation! I've never flown a bus, but one of my buddies explained it best when he said to think of the lever like the "shifter" for an automatic transmission. LOL! I've enjoyed reading about your life on the 330 but I'm about a generation or so behind on the 75/76 (but that's a big step up from C-141's). Maybe someday I'll fly 1990's technology.

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  18. Hey Steve... you'll catch up to the new technology and then leap ten steps ahead. I'm still trying to figure out, "what next."
    Thanks for the comment!
    Tell your buddy I love his explanation.

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  19. We don't make mid point checks on my plane at my company. Can't vouch for what others are doing now.

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  20. During the approach, if the autothrust is on,do you keep your hand on the thrust levers in case the thrust becomes too much? What would you do incase the autothrust system failed?

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  21. Always keep your hand on the thrust in the event you need to go-around. And if the auto thrust fails... Fly the plane, just as if you didn't have it.

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  22. Hi, in the case you are flying the Cruise phase of flight, lets say autopilot and autothrust is set to CL and suppose there is turbulence so you would like to reduce stress in the plane, Is a good idea to reduce speed? In case it is, suppose that things get worst and you loose speed information, then the autopilot would disengage, in this case, would the plane recover the power to a CL position as in manual? or you manually need to move the thrust to get more power?

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  23. In turbulence... yes we reduce speed. But not with the thrust lever position, but with the speed bug. Remember CLB thrust lever position enables power "up to" climb. Whatever is needed.

    If "autothrust" fails then we have manual control of the thrust to increase or decrease as necessary. When would we want full climb power in cruise? Probably never.

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  24. Yes, lets put this situation: Cruise normal flight autopilot set, thrust lever position in CLB, bug speed set to a little less than normal, and severe turbulence in the night. So far so good.

    Now suppose that for some reason, 3 pitot tubes fail, and computer can not rely on any speed information and autodisengage, up to this point we dont know how much the autothrust reduced power to keep the airspeed set, since the last measures were faulty, so when it autodisengage to give control to the pilot neither the computer nor the pilot know the actual speed, and a condition of stall could be happening... My question is, once the computer disengage to give human the control, and just before she/he touches the thrust lever, would the engines go to a max CLB power or will stay at the low power were the autothrust left it?

    Thanks Karlene, your blog is one of the most enlighting I found in the internet! great job!

    A flight Sim enthusiast.

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  25. Dear Flight Sim enthusiast,

    Autothrust disconnection by either pushing the FCU A/THR pb or a system failure will result in what Airbus calls thrust lock.

    Thrust lock freezes the power at the current setting when autothrust becomes disconnected and the thrust levers are in the CL detent (or MCT with one engine out).

    So yes, the power will stay at the last setting. Which is a good setting because that's what we were using before it disconnected.

    Thank you for the nice comment!

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  26. when you are climbing to cruise altitude, and you have passed thrust reduction altitude, how much thrust does the A330 use?

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  27. The A330 uses whatever thrust she needs to maintain the required speed.

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  28. I thought that pitch is used to maintain the required speed during climb, while the thrust is used to maintain a fixed climb thrust setting.

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  29. Jet Airliners… great questionQ The answer is… it depends.

    After takeoff, at thrust reduction altitude, thrust levers are placed in the CL detent. This allows the autothrust to use any setting up to climb thrust to meet autoflight system demands.

    On the Airbus the active autothrust mode is directly related to the vertical guidance mode.

    So… while you’re right… there are times pitch does control the speed…. only “IF” the autothrust is in the “Fixed” thrust mode. If the aircraft is in the “Variable” thrust mode, pitch is used to control the vertical path.

    What mode is which and how do you know? If the active vertical mode is: V/S, FPA ALT*, ALT, ALT CRZ*, ALT CRZ ALT CSTR*, ALT CSTR G/S*, G/S FINAL DES and all APs and FDs off then you will see SPEED/MACH in column number one, and the autothrust is in variable thrust. All other times are in fixed.

    So… climbing out in CLB, and OP CLB you’ll see THR CLB and this is fixed thrust, and the pitch is used for speed. But, if you climb in VS, or during altitude capture and level off the thrust will be in variable… providing what it needs to provide to maintain the speed. I hope this clarifies.

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  30. I only know basically. Taxi at 40 % power...then at runway pull to idle position and foot brake then push to 40 % power for stabilaze for 5 seconds...then push to 100 % power for Toga....

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  31. I only know basically. Taxi at 40 % power...then at runway pull to idle position and foot brake then push to 40 % power for stabilaze for 5 seconds...then push to 100 % power for Toga....

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    Replies
    1. I am most certain you are not alone on that knowledge. But now you know more!

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