B 777 Primary Flight Controls

[@Hopeless_and_Forlorn]

As an aircraft mechanic, my experience with Boeing aircraft was limited to the 737 and 757 models before my retirement. Seeing this video, I am surprised to see how many of these components in a fly-by-wire Boeing are similar or almost identical to components found on the 737-100 series, which went into service in 1968, and the 737-200 of 1969. Feel and centering units, force transducers, trim actuators, force limiters, lost motion devices, LVDTs, power control units, stick shaker, breakout mechanisms, and ball screw actuators all play the same roles in old Boeings and new. Missing, of course, are the long runs of cables that connected pilot inputs directly to flight control surface actuators, and even those were not effective for rudder control on the 737 without hydraulic pressure. Also missing is the aileron/spoiler mixer unit. The SP-77 autopilot on the original 737, although purely analog, was really pretty sophisticated for its time. In fact, for roll and pitch control the basic operating mode of the autopilot, and the default mode when first engaged, was, believe it or not, a fly by wire system. It was called Control Wheel Steering mode, or CWS. To an observer, it would seem that the flight crew was still using manual steering with the autopilot engaged in CWS mode, using the control column and roll control wheel in the same manner whether the autopilot was on or off. However, in CWS control surfaces would not respond directly to the inputs from the column and wheel. Rather, the forces applied by the pilot would be sensed by the force transducers, sent to autopilot boxes contain analog computers, and conditioned signals then sent to hydraulically-powered control actuators (power control units) to move the applicable control surfaces through direct mechanical linkages. On the 737-300 and later aircraft, separate autopilot actuators, also hydraulically powered, moved the inputs to the PCUs, rather than having autopilot control actuators built directly into the PCUs. Since the control cables already linked the control surfaces to the column and wheel, movements of the control surfaces caused by autopilot inputs would back-drive the wheel or column as the pilot's force inputs were made good. If the autopilot made an uncommanded movement, the pilot could override the autopilot by applying more force than the autopilot actuator could produce, and disconnect the autopilot if necessary with a push button on either control wheel. It may seem as if the CWS mode was redundant to manual control, but in fact it provided rate control, bank and pitch angle limits, and an overall stability to airplane flight. It would hold a heading and a pitch angle if no other autopilot mode was selected, ensuring that the airplane did not leave its intended attitude if the pilot was making no steering inputs. CWS was and is a very good autopilot operating mode, and it provided the basis for today's Boeing fly-by-wire airplane operations.

[@raymondjackson6069]

That was great, and it's always nice to get the skinny, from those who know plenty! Thanks and cheers!

[@pierreetienneschneider6731]

So, in CWS mode, the plane did everything the A320 does in terms of flight envelope protection, ie overbank, AoA protection/stall prevention, basically everything needed... And all of this done in analogue. Brilliant engineering.

[@kitbaker8521]

Great training video. These type of videos were ancillary when I was flying…live instructors were the norm until much later. We had these to watch for reference and independent study but they weren’t distributed. They were available to watch in a training center usually in VHS format. . Because students have been exposed to this by live instructors, these videos were good, but not critical and often had a tendency to make a student very sleepy. Odd, but it has the same effect today…

[@desmondantony7786]

Great video! Much appreciated. Gives a better understanding on how flight control components work.

[@denniswise1460]

When Boeing was Boeing.

[@Airbus_a320_lovers]

Now it’s McDonnell Douglas

[@AmNesia-r5h]

@denniswise1460 it's crazy how quickly a lax regulatory environment and capitalism caused a great company to become totally worthless in my eyes. The only reason the stock still trades is because of all the fraud they commit towards american taxpayers with their military contracts.

[@gasgasgas]

Now it would be painted in rainbow color and the idea would discuss what the correct pronouns are for each part

[@denniswise1460]

@ please take your toxicity elsewhere. My comment had nothing to do with your closeted comment.

[@Phil-y8c]

Did your feelings get hurt?

[@TheE71462]

Real piece of engineering, many many studies hours , This beautiful piece doesn't fall from the sky or kick a street light. then, a lot of hours for testing, validation, trials, in flight, stress tests, respect to all these engineers

[@MisterKaribOfficiel]

[@RaoulStankovitch]

I got to see "The Iron Bird" 3 decades ago... Everything hydraulically controlled was laid out in a huge hanger. There was even a partial cockpit from where where the hydraulics were operated. Above the floor..

[@morpheus_9]

775,000lb max takeoff weight is insane for the 777-300ER, that’s the same as the 747-100! Each engine makes 115,000lbs of thrust which is insane

[@edmyers6919]

The Thrust amount it quick staggering.

[@visionist7]

The downside is the very high wing loading compared to the original 777, leading to very low initial cruise altitudes when taking off fully loaded - below 30,000 feet. The 777's "champions" never mention this "feature"

[@Phil-y8c]

@@visionist7 Note to self: Stay away from Mt. Everest and K2.

[@rogerdavis2056]

Great video, I used to make flaperons for Boeing years ago.

[@pfsantos007]

The algorithm brought me here. All the fail safes and backup systems written in blood, and we're still learning.

[@raymondjackson6069]

Very sophisticates, but still not as sophisticated as my 2005 Chevy Impala (LS). At least to me! Great video!

[@sky173]

Best video I'll watch all day. Thx for sharing.

[@ThisPartIsAndrew]

I've always wondered why the tiny flight engineers inside the walls of the fuselage made so much weird noise and now I know why: they are actually levers and pinions and not tiny flight engineers

[@TotalAnomy]

I believe it's cheaper to use levers and pinions than tiny flight engineers all over the place

[@ThisPartIsAndrew]

@TotalAnomy lol

[@dcf8978]

As a whole this seems very complex, but the video does a good job breaking down the functions of individual parts. I am almost surprised that I can understand what is going on.

[@wickedpawn5437]

Fantastic! This shows why these machines are $250 million apiece.

[@herkesyadahickimse2397]

it is amazing video, I can understand system better now

[@kepamurray1845]

I sit here watching this thinking it is fantastic design. I seen the 777 doing it's certification flights as an apprentice. I have had extensive experience on 747 and 767 and I still think that you really can't do much better than this. Computers cause confusion for pilots. They need a common sense feedback for what they are doing. This is precisely how all big jets need their flight controls implemented.

[@ozzman1997]

At 1:30 when he says “bank angle” it sounds almost identical to the aural warning for bank angle. Lol

[@koriko88]

Bank angle. Bank angle. Bank angle…

[@Kijo62]

Do you have similar videos for other systems?

[@DontGetMeICantEven]

As I have always suspected: there's nothing much to the engineering of passenger aircraft flight control systems! /s Interesting video, thanks!

[@gokmachine]

Its wonderfull to watch bus so much more expensive then one servomotor and control software.

[@DrQuagmire]

This is an Air Canada training video. The same voice over and style is how the safety video was shown when the 777 first came out. Yup, when Boeing was just Boeing.

[@Phil-y8c]

You sure? I never heard an "eh" while watching this.

[@DrQuagmire]

@ yup, I’m sure.

[@AlexKoltsov]

Very good video, thak you!

[@CyberSystemOverload]

When videos were narrated by a human. When Boeing let engineers have a voice. I watched the first flight of this great machine. Its the ORIGINAL KING TWIN. It eventually inspired its rival to make the A350.

[@francisbeaudry8598]

frome quebec so good infos tanks so mutch merci beaucoup

[@라마헬기]

좋은 공부 합니다❤

[@qiuweida]

不得了，传统的钢丝传动和现代飞控的结合物。

[@allezvenga7617]

Thanks for your sharing

[@TunChit-g5g]

China: write that down! Write that down 😮

[@aleksandrlisov3944]

Thanks a lot🤝

[@Steven9675]

Question - where is the redundant system?

[@MrDastardly]

When Boeing aircraft were quality. Long gone.

[@Rohit.Ginkala]

Wow😍

[@TRPGpilot]

Thanks for uploading!

[@michaeli1833]

Great video. Thanks

[@MathaGoram]

Long live CATIA?

[@twiff3rino28]

Must be mid 90s looking at the styles and graphics.

[@pierrerobert6458]

I feel safe in the B777

[@pilotM3]

And rightfully so, it’s the best,most reliable and robust airliner!

[@visionist7]

@@pilotM3 all airliners are robust. Plenty of crash landings in plenty of airliners with a 100% survival rate

[@pilotM3]

@@visionist7 yeah, the triple is the most..

[@visionist7]

@@pilotM3where's your proof

[@mgsegoo1124]

Awesome

[@hoedenbesteller]

I fell asleep after 5 minnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnn

[@satyaranjanbehera1538]

Great video. But you didn't cover the THS system mechanisms and it's alternate control mechanisms in last part.. Please cover it with another video.... 😘💕💘😍

[@Amerikanin2numarali_ustasi]

faydali!

[@Alpha787-9]

Good Video respect 👍

[@uumuu]

777 was peak boeing

[@ابويزيد-ف1خ]

Thanks

[@cinemoriahFPV]

Pre DEI Boeing

[@Phil-y8c]

Indeed

[@meepk633]

Boeing and Air Canada both had DEI programs before, during, and after this aircraft was designed and used.

[@MisterKaribOfficiel]

Olly crap, That's yesteryear Flight Controls

[@thedolphin5428]

I did not see any mention of the retro encabulator, the spurving bearings, or the panametric fan. Without these, the system is bound to fail sooner or later.

[@mcsquared100]

All powered by a Flux Capacitor obviously

[@ВасилийДударов]

и НИКАКОГО ДУБЛИРОВАНИЯ. в РФ -тройное дублирование-даже на мех управлении не говоря уже об электронном...Это видимо у вас в США осталос с Дугласом годов 55-70.А после.Переставили дублировать и страховать полагаясь на электронику.где 1 проводок оборвался от вибрации или окислился и все катастрофа-чловек 300 разбились😢

[@oisiaa]

Or...you know...straight up fly by wire like Airbus and skip all of this complexity.

[@visionist7]

If they ever build a new airliner they'll simply everything

[@kishio.m2956]

If not Boeing, I'm not going.

[@thedolphin5428]

I mean, seriously. How many people in the world actually need to know this. About 100 Boeing mechanic apprentices the workd over who might service such stuff. Pilots certainly don't. Yet here it is, posted up on YT with 3,700 views by plane nerds

[@straightpipediesel]

An airline hires 10-15 mechanics per plane. And Boeing doesn't do any aftermarket service unless it's serious and non-routine, like a crash.

[@kuldeepofficial740]

May GOD bless you

[@julesdomes6064]

If it's Boeing I ain't goin'!

[@kennethhoffman8845]

Grow up

[@julesdomes6064]

@@kennethhoffman8845 I am a fully grown engineer with an MsC in aeronautical engineering. I also have a sense of humor. 👍

[@kennethhoffman8845]

@@julesdomes6064 Okay... So I'll grow up for both of us... and guide the journey with my dry as silica gel sense of humor at all times... Deal? 😂

[@kennethhoffman8845]

@@julesdomes6064 BTW... After watching this and many other videos that delve into the intricacies of a modern commercial airliner, I would submit that the average, grumpy, simpleton passenger has no capacity whatsoever to appreciate all that lies beneath that sleek exterior they see parked at the gate.

[@JeepAndFly]

All of this mechanical complexity is not needed for flight by wire. Insane they kept it instead of a joystick like airbus

[@matthiashartge5520]

Well the yoke has e.g. the advantage that one pilot can see what inputs the other pilot makes. There are pros and cons to both systems. And actually, the sidestick has quite some impressive mechanics to it as well ;)

[@jameskirk2579]

Is it safe to show such mencanism ?????

[@matthiashartge5520]

Why should it not be safe?

[@techdefined9420]

I didn't think the 777 was so backwards and still having some cables for control. Real modern fly by wire aircraft use electric backup actuators.

[@Pilotman28]

how many aircraft have you designed again?

[@techdefined9420]

@Pilotman28 How many have you designed?

[@IllusiveDude]

​@@techdefined9420 He's not the one complaining

[@coriscotupi]

That's because of Boeing's decision to make the 777 somewhat of a hybrid as far as flight controls go. The fly-by-wire logic is there, but controlled by a fully mechanical pilot interface, with all the bellcranks, springs, pushrods and cables that this entails.

[@VictheSecret]

If you think it's backwards, could you list the qualifications that you have that would allow you to disagree with Boeing's design team?

[@misterbig9025]

Today's Boeing is made in India

[@ghostrider-be9ek]

seven seven seven