19 votes
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How do aircraft throttle levers allow the pilot to move the levers, as well as motors to move the levers for autothrottle?

The exact details for the autothrottle system obviously depend on the aircraft. I will focus on the Boeing 777 as an example here. The B777 FCOM (Flight Crew Operating Manual) describes the thrust ...
Bianfable's user avatar
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18 votes
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How do pilots set the exact amount of thrust needed for a reduced power takeoff?

The EMB-145 used a combination of FADEC settings and the thrust levers to select the desired thrust and to signify the need for additional thrust. The thrust levers had a detent that selected "100%"...
casey's user avatar
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14 votes
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What mode is the Boeing 777's autothrottle in right after touch down?

During the flare somewhere between 25' and 50', the A/T retards the thrust levers to idle. They remain in idle mode until reverse thrust is selected which automatically disconnects the A/T. In the ...
Mike Sowsun's user avatar
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10 votes
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How does the B737's 'throttle offline' setting work?

That article is about somebody's simulation. In the real aircraft, the pilots can always override the A/T and can always turn it off entirely. The A/T will push the throttles toward the target ...
Ralph J's user avatar
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9 votes
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Can autothrust keep the plane aligned with the runway during crabbing?

EDIT: I take your question as "when crabbing the aircraft for landing in strong crosswind, is the auto-thrust precise enough to maintain horizontal alignment with the extended runway centerline?" No. ...
kevin's user avatar
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8 votes

What determines the "acceleration" and "thrust reduction" heights?

The Airbus reference Getting to Grips with Aircraft Performance provides a description in section 4.1 Takeoff Flight Path. They describe the takeoff flight path as four segments as shown in the ...
Gerry's user avatar
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7 votes

What is a "flare-out" and why does auto-thrust reduce thrust during flare-out?

The proper term is "flare" not "flare-out". "Flare" is a term used to describe the act of raising the nose of an aircraft in order to increase lift and stop descending in order to land on a runway ...
Mike Sowsun's user avatar
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7 votes

How do pilots set the exact amount of thrust needed for a reduced power takeoff?

caseys answer nicely describes the procedure for the Embraer 145. Since you specifically mentioned the Boeing 737 and Airbus A320, here is how it works for these aircraft: Boeing 737 All Boeing ...
Bianfable's user avatar
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6 votes

How do pilots set the exact amount of thrust needed for a reduced power takeoff?

Usually power output for a jet engine is gauged from its low pressure turbine speed. In turbofans, this corresponds to the fan speed, displayed as N1. In general, the derated takeoff thrust will be ...
Romeo_4808N's user avatar
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6 votes
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Why do most propeller-powered planes not have an autothrottle?

Because each jet engine only has one lever; each piston engine has three. Jet engine's throttle is pretty straight forward - move forward, more power. The computer automatically manages fuel flow to ...
kevin's user avatar
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6 votes

What is TOGA LK in Airbus 320? How to come out of TOGA LK?

TOGA LK (TOGA thrust locked) is displayed on the FMA after an activation of the ALPHA FLOOR protection when the activation conditions are no longer fulfilled (A FLOOR is displayed during the ALPHA ...
Bianfable's user avatar
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6 votes
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On the Airbus A320 family, when does the autothrust disconnect?

The autothrust disconnect is described in the Flight Crew Operating Manual: A/THR DISCONNECT When the A/THR is disconnected, it is neither armed nor active. The A/THR can be disconnected in two ways: ...
Bianfable's user avatar
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5 votes
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Can autothrottle be used without autopilot (and vice versa)?

They can be used individually, yes. When flight directors (or autopilot) are on then they dictate what auto throttle should do. But it's not a good idea to fly manually, use auto throttle and have ...
Jan's user avatar
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5 votes

What is Auto-thrust?

In its basic form, it is just like the cruise control in a car.* Here is a photo of the autopilot control panel on a Boeing 777. Note the "IAS 200" window on the left: IAS stands for "indicated ...
kevin's user avatar
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5 votes

Which computer controls auto thrust on an Airbus A320?

More specifically on your question: See diagram below: In the autothrust mode (A/THR function active), the FMGC computes the thrust, which is limited to the value corresponding to the thrust lever ...
Lidakis Manolis's user avatar
4 votes

Can autothrust keep the plane aligned with the runway during crabbing?

From your question, it seems that you have the following situation: An aircraft is having a constant angle w.r.t. the runway to compensate for a crosswind. When this crosswind increases, the aircraft ...
Sanchises's user avatar
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4 votes
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What is TOGA LK in Airbus 320? How to come out of TOGA LK?

TOGA LK is short for Takeoff Go-around (Power) Locked. Which means, due to some kind of situation (e.g. reaching Alpha Floor), the aircraft decided it'd be a good idea to spool the engines up to ...
Maverick283's user avatar
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4 votes

Can autothrottle be used without autopilot (and vice versa)?

Yes it can. Autothrottle on most large aircraft (including 777) is considered a separate system from autopilot. To that end, the modules/boxes that control the autothrottle and autopilot are separate ...
Frank's user avatar
  • 2,403
4 votes

Can thrust be selected manually in a plane with autothrust? If yes, how?

You are correct that different planes operate slightly differently, but they are mostly pretty similar. Just as with the autopilot, the autothrust can be disconnected and the airplane can be ...
fooot's user avatar
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4 votes
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Do Rolls-Royce Trent 700s (on the Airbus A330) automatically spool up when selecting *only* idle reverse?

To anyone who is interested, I found the answer. When idle reverse is selected, it will enter "elevated idle" mode for a few seconds to more quickly provide full reverse if that setting is ...
Charles Nicholson's user avatar
3 votes

Do modern aircraft automatically manage the deceleration to Vref?

This depends on the aircraft. Airbus aircraft have a managed speed mode in the FCU (flight control unit), where the speed is completely controlled by the FMGS (flight management and guidance system). ...
Bianfable's user avatar
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3 votes
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Are there any autoland capable aircraft without autothrottles?

I'll try to answer, even if it may not be the answer you expect. To directly answer your question, yes, there are (were) aircraft with autoland system and no autothrottle. Hawker Siddeley Trident 1 is ...
ocirocir's user avatar
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2 votes

Can autothrust keep the plane aligned with the runway during crabbing?

The question was not whether the autothrust/autothrottle DOES keep the aircraft aligned, but whether or not it CAN keep aircraft aligned. There is a very interesting, but not well known story that ...
Frank's user avatar
  • 2,403
2 votes

Would an A320 override the autothrottle due to an erroneous radio-altimeter?

In AIRBUS, The «Flare mode» brings automatically the thrust to idle provided the autothrust is under the dependance of the FMGS, in this case irrespective of the pilot action moving back the levers ...
user40476's user avatar
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2 votes
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Airbus A320 automatic speed mode protection in SRS vertical mode

High speed protection is still available (in normal law) in SRS (check FCOM DSC 27 20-10-20). What you will not have is the reversion mode of the autothrust to Speed. You will get the protection (...
Radu094's user avatar
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