Questions tagged [fly-by-wire]

A technology which moves control surfaces by processing pilot input via software.

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The F-16 has a FLCS that constantly holds 1 g. What happens on high pitch angles?

The F-16 has a FLCS that constantly holds 1 g. What happens on high pitch angles? What is defined as 1 g? let us say that you climb with 60 degrees relative to earth, does that mean that the FLCS just ...
Sandpatch's user avatar
1 vote
1 answer
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A220 Direct Law Mode trim control

When A220's PFCCs are all failed, the airplane enters direct law mode. In this mode, from description, pilots should manually control stabilizer trim. When this situation occurs, does pilot need to ...
moon's user avatar
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2 votes
2 answers
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Different Engine/Prop Sizes on Same Wing/Single Craft?

On a four propeller/engine wing, I’m wondering if theoretically at least, you could have a larger engine near the root of the wing with smaller engine(s) further out on the span..?.. If you could have ...
Greg Dean's user avatar
2 votes
0 answers
170 views

Boeing 777 PCU Synchronization of Duplicate Hydraulic Actuators for Control Surface Deflection

I have a question regarding the redundancy of hydraulic systems used to deflect the control surfaces of a Boeing 777 aircraft (or the like). We know that "the elevators, ailerons, and flaperons ...
Adam Yassine's user avatar
4 votes
2 answers
1k views

Has any manned aircraft been hijacked electronically?

Has anyone ever taken control of a manned aircraft from the pilot by exploiting security vulnerabilities in the electronics system?
Someone's user avatar
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2 votes
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Which Aircraft Utilise Fly-By-Light Controls?

Although I can find reference to the Eurocopter EC135 being a test bed for fly-by-light, I am not sure if it has entered production with the system [1]. The only confirmed aircraft I can find is the ...
AerospaceDoctor's user avatar
2 votes
2 answers
1k views

How does the fly-by-wire on the new F/A-18 Super Hornet work and what is it maintaining?

I am trying to replicate the fly-by-wire (FBW) system of the Super Hornet for a game called SimplePlanes. I was wondering if it is maintaining a certain $g$ number, turn rate, angle of attack, or a ...
WWIIGEEK's user avatar
7 votes
1 answer
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Why do the ailerons on an A320 droop when the engines are shut off and the 787 ailerons dont droop when the engines are shut off?

I have been wondering why the ailerons on the A320 (and other Airbus aircraft) droop when there is no power from the hydraulic pump. From my understanding of hydraulic actuators, the position where it ...
John's user avatar
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3 answers
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Zero experience to A320 in seven months?

Some flight schools advertise a "direct path to A320 or B737 f/o after 7 months." Is it a more difficult transition to go to a fly-by-wire aircraft straight out of initial training? Are ...
Chirp907's user avatar
14 votes
5 answers
5k views

What is the difference between autopilot and fly-by-wire system?

I observed a lot of people misinterpret these words. In my opinion, autopilot assists the pilot by inputting the commands to the computer whereas fly-by-wire (FBW) system sends and receives signals ...
Auberron's user avatar
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In theory, can jetliners remain controllable after losing the entire tail section?

The scenario here is a detachment of the tail,one with the whole empennage. Could a variant of an existing model of swept winged jet airliner be made to remain controllable, using ailerons, ...
Abdullah is not an Amalekite's user avatar
9 votes
3 answers
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Under what circumstances does the F-16 and possibly similar fighters deploy leading edge slats?

What does the F-16 (perhaps other fighters as well) use to decide when to deploy leading edge flaps? I would assume angle of attack, airspeed, stick deflection, or some combination of the three, are ...
MD88Fan's user avatar
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Why does the flare mode of the A321neo engage 50 feet higher than the A321ceo?

Following is taken from the operating manual of A321neo: When passing 100 ft RA, the THS is frozen and the normal flight mode changes to flare mode as the aircraft descends to land. The flare mode is ...
Mike's user avatar
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1 answer
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What protections and feedback does the fly-by-wire of the Boeing 777/787 provide?

I know the Boeing 777 and 787 run on Fly-By-Wire. I was wondering: Do they have the Alpha Floor or Flight Envelope protections Airbus aircraft have? Do they have force feedback/force feel? The 737, ...
tizmataz77's user avatar
1 vote
0 answers
172 views

How do the A320 flight controls reconfiguration laws work?

Can someone explain in simple terms the reconfiguration laws? I have hard time understanding ELAC, SEC, FAC Priorities in FCTL Architecture Diagram.
Sapna Nahata's user avatar
14 votes
3 answers
7k views

Do pilots use the pedals in flight on planes with a sidestick (Airbus)?

Do the pilots flying sidestick aircraft with fly-by-wire control systems, such as the Airbus A320, use the rudder pedals while in the air? Or does sidestick input affect both the rudder and the ...
Emil Lundin's user avatar
3 votes
2 answers
363 views

How is flight envelope protection implemented in Dassault Falcons?

In normal laws, envelope protection is implemented differently on Boeing and Airbus fly-by-wire systems, as highlighted in this question. I don't want to reopen a debate about which one is better (...
Manu H's user avatar
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7 votes
1 answer
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Was there more than one incident or accident where an Airbus FBW aircraft reverted to mechanical backup?

There was an accident Smartlynx A320 training flights MYX-9001 at Tallinn on Feb 28th 2018, where ELAC pitch control failed due to fault in the stabilizer actuator, and then both SECs failed due to ...
Jan Hudec's user avatar
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Why do the A320’s primary flight controls have hydromechanical backups only for the rudder?

The A320 is primarily a fly-by-wire aircraft, with the pilots’ joystick and rudder-pedal inputs not going directly to the flight-control surfaces, but, rather, to the aircraft’s flight-control ...
Vikki's user avatar
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3 votes
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Does joystick position control bank angle in some Airbus aircraft? And what happens when the pilot deflects the joystick when wheels are on ground?

Does joystick position control bank angle rather than directly controlling aileron/spoileron deflection in some Airbus aircraft? Also, what happens when the pilot deflects the joystick when the all ...
quiet flyer's user avatar
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Does anyone have photos of internal parts of ELAC, FAC, SEC or Boeing 777 flight computers?

I'm an electrical engineer and I'm interested in civil aviation, more specifically in fly-by-wire planes like the Airbus A320, Boeing 777 and others. But I fell in love with the Airbus A320 as it is ...
mrhakerfox's user avatar
2 votes
1 answer
470 views

What controllers are used in Airbus/Boeing fly-by-wire systems?

I was wondering, what controllers are used in airbus or Boeing aircraft fly-by-wire systems to control servos? Who manufactures such controllers, or are the systems controlled from flight computer ...
Joshua Lincoln's user avatar
1 vote
2 answers
405 views

How can I tell if an aircraft is equipped with fly-by-wire or with a FADEC?

Can anyone help me with a link or advice on how I can identify whether an aircraft is fly-by-wire (FBW)? I understood the function of FBW, however if I want to know if a SA227 or smaller type of ...
Bambo Bamborowicz's user avatar
2 votes
3 answers
652 views

Are fly-by-wire fighters protected in AoA?

When thinking about fly-by-wire, I always think about civilian aircraft (Dassault Falcon 7X, Airbus A350...) for which protections are implemented to ensure the aircraft stays in its designed flight ...
Manu H's user avatar
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On Airbus aircraft, can the pilot control the aircraft when the autopilot is active?

I am looking at the schematics of computerized control for Aibus aircraft and I do not understand the relation between the various control law and the autopilot. Under "normal law" can the pilot ...
Ahmed's user avatar
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8 votes
1 answer
863 views

Does the pilot still have final control authority on modern Boeing airplanes?

In this answer it is said that Boeing (contrary to Airbus) gives final authority to pilots, but the example is about a 747-100(SP). This answer states, that modern Boeings have have a lot of fly-by-...
Arcfrostt's user avatar
6 votes
2 answers
785 views

How does the F-16 side stick convert pilot input to an electrical signal?

In What is the motivation behind designing a control stick that does not move? the F-16's control stick is discussed. What is the method that is used to sense the pilot's input to the stick and ...
Steve's user avatar
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20 votes
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What is the maximal acceptable delay between pilot's input and flight control surface actuation?

While I was watching a cockpit video of an A330 landing in which the pilot was frenetically moving its sidestick, I wander what was the reaction time of this flight by wire system. Indeed, the time ...
Manu H's user avatar
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10 votes
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Could modern unmodified Airbus aircraft be used for zero-G flight?

ESA operates a mostly-stock A310 for their zero-G science flights, which doesn't have the flight envelope protection of more modern planes. Even then, a third pilot is required to monitor warnings to ...
Yet Another User's user avatar
8 votes
3 answers
998 views

Does fly-by-wire permit smaller tail fins (area and thickness) for jetliners?

To prevent an XY problem, here's the context: A striking feature of the 777 is how small and thin its tail fin is compared to the 747. When I asked about this many, many years ago, someone told me ...
user avatar
6 votes
1 answer
1k views

How can the F-16 remain stable when there is a loss of hydraulic power?

Edit for justification: This question is different from If the EPU (Emergency Power Unit) on a modern fighter jet fails, will the aircraft drop out of the sky? for the following reasons: The ...
AlphaCentauri's user avatar
2 votes
1 answer
275 views

What is the input range of common fly-by-wire controls?

What's the range that typical fly-by-wire controls (let's take A320 and B777 as examples) allow inputs in? The A320 controls in the y-axis of the side stick (forward/backward axis) the g load - what'...
Florian's user avatar
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12 votes
1 answer
789 views

What is the Space Shuttle's command law?

The Space Shuttle was fly-by-wire. In today's fly-by-wire systems, the command law commands either the load factor and the roll rate (e.g., A320's normal law), or the surface control deflection (e.g., ...
Manu H's user avatar
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4 votes
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1k views

On an A320, will the aircraft compensate for constant pilot rudder input?

As I understand from answers to the question What does rudder input control in normal law in an A320?: the rudder deflection is the result of the sum of pedals input and plane's FBW command in normal ...
Manu H's user avatar
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8 votes
1 answer
2k views

What is the trim wheel behavior on the A320 family?

The Trim Wheel in the A320s usually is moving by itself, representing the current stabilizer position (or rather command). Before takeoff I believe it is set by hand to set the takeoff trim. During ...
Maverick283's user avatar
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9 votes
2 answers
656 views

Do fly-by-wire fighter aircraft automatically reverse the direction of control surface deflections during a tailslide?

During a tailslide (a flight regime where the relative airflow over the aircraft is from the tail towards the nose; i.e., an attack angle between 90º and 270º; i.e., the airplane is moving tail-first),...
Vikki's user avatar
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1 vote
0 answers
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Are there attempts at fly-by-wire servo flap controlled rotor?

Reading this question and then this document about servo flap controlled rotor I was wondering if there has been any attempt at building one fixed hub helicopter with twistable blades hosting at 75% ...
user721108's user avatar
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0 votes
1 answer
258 views

Does the HAL LCH have fly-by-wire?

Is Automatic Flight Control System (AFCS) the same as Fly-by-wire? If not what's the difference? India’s Hindustan Aeronautics Limited (HAL) has carried out the first flight of a Light Combat ...
aspdeepak's user avatar
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6 votes
2 answers
3k views

In an Airbus A320, when alpha protection is active, is pitch protection no longer available?

The A320 FCOM chapter 27 flight controls, normal law, protections, shows a diagram how the sidestick input is used when protections are active. When high angle of attack protection is active the side ...
Jan's user avatar
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6 votes
1 answer
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What sort of control mechanisms (i.e., PID controllers) do modern FBW aircraft use?

It's a well-established fact that aircraft like the Boeing 777, and all Airbus passenger aircraft that were designed after the A300, feature a digital fly-by-wire control system. Considering the ...
SaiMachi's user avatar
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0 votes
1 answer
146 views

Does the FBW system of a passenger aircraft use differential thrust for yawing? [duplicate]

Are there situations where the fly-by-wire system of a commercial passenger aircraft will use differential thrust to yaw? Or is that even possible at all (i.e. do the necessary interfaces exist)? I ...
Daniel's user avatar
  • 823
1 vote
1 answer
1k views

Fly-by-wire vs hydraulic systems [closed]

So, the great old argument, flyer-by-wire systems vs conventional hydraulics. I was wondering which one was better and why. Which one is safer? Pros and cons in terms of safety? Basically, I just ...
lpydawa's user avatar
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4 votes
2 answers
2k views

Were Airbus planes always fly-by-wire?

So, as most of you know, Airbus has adopted fly-by-wire (fbw) technology. Pretty much every single plane made by Airbus is a fbw plane. So I was wondering, before computers were everywhere, did Airbus ...
lpydawa's user avatar
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15 votes
2 answers
5k views

How does the Boeing 777's yoke of both the captain and the first officer have synchronized movement?

On Airbus planes, the side stick of both the captain and co-pilot are not synchronized in movement, meaning if you the captain moves the side stick, the co-pilot's side stick will not move together. ...
lpydawa's user avatar
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1 vote
2 answers
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Why did this A320 stall protection demo not hold Valpha max?

This video is about the Airbus A320 High angle of attack protection At 4:54 - 5:13 why did it pitch down? I know it is trying to maintain Valpha max but if it would ...
Gary Zenger's user avatar
8 votes
1 answer
8k views

Why don't the A380 and A350 have trim wheels?

(wikimedia.org) A350 thrust levers without the flanking trim wheels. Why don't the Airbus A380 and A350 have trim wheels? On the other fly-by-wire Airbus aircraft the trim wheels are there for ...
user avatar
2 votes
1 answer
599 views

Could simple fly-by-wire controls be installed in a prototype as quickly as a mechanical system with an autopilot?

It seems that fly-by-wire systems can take longer to get certified as the testing requirements are much more extensive. A prototype aircraft wouldn't have to pass these tests. How much more time or ...
H. Soukup's user avatar
34 votes
6 answers
9k views

Why can't the A320's computer-imposed limits be overridden?

Under the investigation section of US Airways Flight 1549, it is noted that [The pilot] asserted that insufficient credit was given to the A320's fly-by-wire design, by which the pilot uses a side-...
Cloud's user avatar
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5 votes
7 answers
2k views

Why did fly-by-wire systems take so long to implement?

The first commercial FBW airplane was the Airbus A320, which was introduced in the late 1980s. This system only worked after decades of research by American and European aerospace companies. If FBW ...
SaiMachi's user avatar
  • 151
7 votes
2 answers
944 views

Can the fly-by-wire system of a modern airliner handle an unstable condition?

According to this answer airliners/large passenger aircraft such as an A320 are designed such that they are longitudinally, statically stable under normal flying conditions. What if, for some reason, ...
Daniel's user avatar
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