Any know about airplanes????

[abunaitoo]

It never ceases to amaze me how many members here know so many different things.
I was watching TV and had a question someone might have an answer to.

With most, if not all, large planes having Hydraulic or fly-by-wire controls these days, is there a feed back system to the flight control (steering wheel)?????
Reason I'm asking is I always see pilots having to pull hard, and fighting the controls, when pulling out of a dive.
I know with the old cable stick-and-rudder all the power was in the arms of the pilot. With the new systems, hydraulic or servo's provide all the muscle power.
If there is no feedback system, it would seen to me they wouldn't be straining to pull back on the controls.

Does make for good TV though.

[Boz330]

I fly little fly by wire stuff (long twisted wire cables) but there are a few heavy iron pilots here that I'm sure will jump in. I believe there are feed back systems on some of the big airplanes anyway.

Bob

[smkummer]

yes, The 727 hydraulic and DC-8 cable system had to be in trim or they would get heavy either way. The 727 hyro system could fail and then it was reverted to manual (like driving a car with the power steering out). The Airbus A300 has an artificial feel to its hydro system so as to feel "normal". All of these aircraft have certain flight controls that lessen with high speed so as to not overcontrol but become active on slow speed flight. Most modern aircraft are flown on autopilot 95-98% of the time but have to fly like "normal" if such systems fail. Currrently type rated on B727, DC-8, A300 and shortly going to the B757/767 aircraft.

[abunaitoo]

So I'm guessing that when you see them on TV, it's ture.
They would have to fight the controls to pull out of a dive.

[oldred]

No not on a modern "fly-by-wire" system, it does have an artificial "feel" to it but it would not cause the pilot to have to fight with it! You can't believe ANYTHING you see in the movies, 99% of what they do is USDA certified BS!!!! I mean think about it, in the movies all a person has to do is reach under the dash pull out two wires and touch them together and BINGO they just drive off without keys in the car they just stole! Never mind the key is also needed to unlock the steering and shifter in addition to the fact that the wires that start the car are totally inaccessible by design.

But back to the airplanes, for instance the original F16 design had a control stick that did not even move and the control inputs were simply from pressure applied to the solidly mounted joy stick. This design never made it to production aircraft however and it was decided to be a very bad idea so a movable stick was designed with artificial control feed-back for a more conventional feel. On a conventional mechanical control linkage, hydro or whatever, there could be instances where the controls could get very heavy but not with a computerized fly-by-wire system. These systems can/are designed so that they can override dangerous in-puts so it would not be necessary to have artificially induced super heavy controls nor would it be desirable in an emergency situation.

[abunaitoo]

I almost never believe anything I see on TV, unless I know better.
I was thinking that if it was fly-by-wire, and the plain lost power, and the pilot was trying to pull it out of a dive, with no power the stick would just flop around doing nothing.
Now if it was hydro assisted and lost power, I would think it would be like when the power steering on your car goes out. You'll really have to muscle it to move anything.
Correct????
Now... if the plane is in a dive, and still has power, and the pilot is trying to pull out of it. Would he still have to muscle the controls?????
Wouldn't the assist take over for the extra force of pulling out????
Sorry if I ask stupid question. I just don't know much about these things.
Probably should just not worry about it. But it's interesting.

[Matt_G]

Now if it was hydro assisted and lost power, I would think it would be like when the power steering on your car goes out. You'll really have to muscle it to move anything.
Correct????
Without hydraulics, you basically have nothing in a large airliner.
Remember United flight 232?
http://en.wikipedia.org/wiki/United_Airlines_Flight_232

[Recluse]

I almost never believe anything I see on TV, unless I know better.
I was thinking that if it was fly-by-wire, and the plain lost power, and the pilot was trying to pull it out of a dive, with no power the stick would just flop around doing nothing.
Now if it was hydro assisted and lost power, I would think it would be like when the power steering on your car goes out. You'll really have to muscle it to move anything.
Correct????
Now... if the plane is in a dive, and still has power, and the pilot is trying to pull out of it. Would he still have to muscle the controls?????
Wouldn't the assist take over for the extra force of pulling out????
Sorry if I ask stupid question. I just don't know much about these things.
Probably should just not worry about it. But it's interesting.

Anything FBW (fly by wire) will have either an APU (Auxillary Power Unit) or EPU (Emergency Power Unit) that will supply electrical current to the flight control computer (FCC) in order that the pilot have control over the flight surfaces.

If THAT fails in a fighter, your next flight control maneuver is to reach between your legs. . . for the ejection handles. I'm not sure how the modern Airbus video-game planes work--I just know that I'd never, ever fly one. There are those who do that love them (Sullenberger, for example) but I know a lot of drivers who don't like the computer making all the decisions.

That old "grimace" while pulling back on the yoke came from the days of cable & pulley flight control surfaces in which you (the pilot) were actually fighting against the airflow in trying to maneuver in extreme attitudes and speeds.

I remember getting some right-seat time during a long cross-country flight in an old A-model KC-135 that was all cable/pulley with only slight hydraulic assist. At low/no speeds, you could FEEL how heavy the flight controls were. At flight speeds, there was no "yanking and banking." Also a reason why it was a two-pilot front office (along with navigator) because it took two strong arms to maneuver that plane in takeoff and landing configuration--leaving the other driver to work the power settings.

As far as television and movies go, it wouldn't be nearly as dramatic and heart-pounding if the left-seater was to simply use his left hand to pull a diving Airbus out of a screaming earth-bound angle-of-attack. Looks more dramatic to have him perspiring profusely and white-knuckling the yoke while the stewardess is wrapped up behind him helping him yank back on the yoke as the passengers are all screaming.

:coffee:

[oldred]

Not a stupid question at all but the answer could be different for different aircraft designs, the basic answer however is that while a total lack of power would be catastrophic it is extremely unlikely to happen. It would be very complicated (and wasteful actually) to design a control system that has redundant systems of both fly-by-wire and mechanical controls, it simply is not necessary. Fly-by-wire systems are state-of-the-art designs with multiple back-ups and a total system failure is even less likely than a more conventional mechanical system.


FWIW, I am not an aircraft engineer, but I assume you already know that, however I have been flying since 1975 and have multi-engine and rotorcraft ratings although I had to quit flying a couple of years ago due to failure to pass my FAA physical exam.

[abunaitoo]

"I had to quit flying a couple of years ago due to failure to pass my FAA physical exam. "

Reminds me of Henry Bowman's father.

Thanks to all for the great information.
Im not a flyer, but I enjoy reading about these things.

I'm old school, and have a hard time trusting anything that depends on a computer to operate. Been an automachanic for many years. I know computers do fail. Sometimes with catastrophic results.

If it's bad for cars, it must be really bad for an airplane.

[geargnasher]

Hollywood. Same reason the foley editor always, and without fail, adds a "brake squeal" soundbyte to every scene in which a car slows to a normal stop: We're programmed to expect it, and it adds to the effect.

Gear

[oldred]

I'm old school, and have a hard time trusting anything that depends on a computer to operate. Been an automachanic for many years. I know computers do fail. Sometimes with catastrophic results.

If it's bad for cars, it must be really bad for an airplane.


Think of it like this, if a car had multiple back-up systems for redundancy if any particular component failed then it would be extremely rare to have to have a car towed. In the case of aircraft using fly-by-wire even a computer failure usually would not be cause for alarm since it would only be part of multiple systems that operate relativity independent of each other, every critical system on board will have back-ups that can operate independently of each other and the odds simultaneous failure would be a very long shot indeed!

[oldred]

Hollywood. Same reason the foley editor always, and without fail, adds a "brake squeal" soundbyte to every scene in which a car slows to a normal stop: We're programmed to expect it, and it adds to the effect.

Gear



Also according to Hollywood airplanes are nothing more than bombs, simply bump one too hard and it will explode into a huge ball of fire! And of course there's my favorite that they have started doing in the last few years where bullets make showers of sparks when they hit something, anything be it wood or metal (as if a bullet would make sparks hitting any material) even though anyone with half a brain knows better!



Come to think of it the absolute stupidest thing I think I have ever seen on tv involved a bullet, it was on a show from back in the 70's, can't remember the name, where a doctor removed a bullet from a gunshot victim and then held it up for the investigating cop to see, it was the COMPLETE round case and all!!! :veryconfu

[geargnasher]

That's funny, Oldred! I laugh every time a movie or tv show has a scene where a doctor or medic removes a bullet from someone: Note that they seem to always take tweezers or forceps and drop the removed bullet in a stainless-steel pan with a loud "CLINK". Sometimes the bullet, just pulled out, has no blood or rifling marks on it.

My favorite, though, is still the westerns with the gunfight scenes where everyone has a 20-shot revolver that can be reloaded in about three seconds while at full gallop on horseback. Or the bulletproof tabletop/wagon bed/door/board-and-batten wall or whatever. The classic "near miss" of a bullet strike on a brick wall and resulting white puff of "smoke" was an effect of a piece of chalk launched from off-camera with a slingshot.

Gear

[Recluse]

FWIW, I am not an aircraft engineer, but I assume you already know that, however I have been flying since 1975 and have multi-engine and rotorcraft ratings although I had to quit flying a couple of years ago due to failure to pass my FAA physical exam.

Have you looked into your eligibility for a sport-pilot (LSA) certificate?

LSAs have some restrictions on them, but as I get older, the restrictions really bother me less--no IFR, no night flying, no speeds above 140kts (that one kind of stings), no Class B, etc.

I wouldn't/won't miss any of that stuff at all. :)

It's worth checking out.

:coffee:

[dmize]

I admit to not knowing **** about airplanes,but nearly all new cars,last 3 years or so are "drive by wire".
The pedal you step on is spring preloaded to give you the feel of stepping on the gas.
I have read multiple times that modern fighter planes simply could not be flown without fly by wire,I assume the same could be said about passenger planes too.
I also had the great fortune to talk to a B-17 pilot,he likened flying a loaded Fortress to rowing a boat while riding a bull bareback,for a couple hours before the co-pilot took over and relieved him for a couple hours.

[fatnhappy]

It never ceases to amaze me how many members here know so many different things.
I was watching TV and had a question someone might have an answer to.

With most, if not all, large planes having Hydraulic or fly-by-wire controls these days, is there a feed back system to the flight control (steering wheel)?????
Reason I'm asking is I always see pilots having to pull hard, and fighting the controls, when pulling out of a dive.
I know with the old cable stick-and-rudder all the power was in the arms of the pilot. With the new systems, hydraulic or servo's provide all the muscle power.
If there is no feedback system, it would seen to me they wouldn't be straining to pull back on the controls.

Does make for good TV though.

Things I know about airplanes:

they need forward velocity to generate lift.
They're not well suited as water craft.
they have thrust, lift, drag and crash as forces acting on them.

Near as anyone can tell the Air Force hasn't accidentally left one up there.

[Jeffrey]

Check out this story about the "Gimli Glider". A 767 ran out of fuel, the pilot lands it dead stick without loss of life.

http://en.wikipedia.org/wiki/Gimli_Glider

[letsmeltlead2693]

I have always wanted to be a pilot, that is my second favorite thing besides lead. Aviation is one of those thing that has fascinated me for a little more than 10 years,I am 19.

[oldred]

Have you looked into your eligibility for a sport-pilot (LSA) certificate?:coffee:




Yes I am familiar with the sport pilot requirements and legally I qualify but unfortunately due to an inner ear problem I sometimes suffer from vertigo so I guess I am permanently grounded.

Dang gettin old is a drag!

[oldred]

I have always wanted to be a pilot, that is my second favorite thing besides lead. Aviation is one of those thing that has fascinated me for a little more than 10 years,I am 19.



Don't wait, just go for it! The good advice I was given about the sport pilots ticket applies to you even more so since it is much easy to get than when I was learning, darn good thing too with today's prices. When I first started taking lessons I was paying $12.50 per hour wet for a Cessna 150 and my instructor was another $8 when he was along, be warned it costs a bit more than that now!

[Boz330]

Don't wait, just go for it! The good advice I was given about the sport pilots ticket applies to you even more so since it is much easy to get than when I was learning, darn good thing too with today's prices. When I first started taking lessons I was paying $12.50 per hour wet for a Cessna 150 and my instructor was another $8 when he was along, be warned it costs a bit more than that now!

Boy is that ever the truth. I paid $9.75 for a 150. About half way through my training it went up to $10 and I bitched like hell about it. I haven't priced a 150 lately but I'll bet it is in the $75 to $80 per hour and you put in the gas.

Bob

[oldred]

Boy is that ever the truth. I paid $9.75 for a 150. About half way through my training it went up to $10 and I bitched like hell about it. I haven't priced a 150 lately but I'll bet it is in the $75 to $80 per hour and you put in the gas. Bob


In 1975 a Cessna 152 could be bought new for less than $15000 plus options, 10 years later the last one produced cost about $47000 I have been told. This, along with fuel costs, is why flight training far exceeded economic inflation and the cost of the aircraft is almost entirely due to greed! Product liability insurance costs skyrocketed because of ridiculous damage awards from the courts, a low time non-instrument rated pilot could take off in a rain storm or heavy fog then when he got disoriented and crashed it was the airplane manufacturers fault! Those high costs can mostly be blamed on corporate lawyers and juries made up of non-flyers who know nothing about aircraft.


BTW, I got my rotocraft rating in a buddy's Hughs 300C and all it cost me was what I paid the instructor. :-D

[LIMPINGJ]

It's allways sticker shock when I see the rental prices of today. Also very few FBOs have any rental aircraft. There is only 1 plane for rent on the field where I work Pounds Field Tyler,TX. Makes the $25.00 wet for the Cessna 310 I got my ME and MEI in seem like a realy good dealand a long time ago.

[Boz330]

In 1975 a Cessna 152 could be bought new for less than $15000 plus options, 10 years later the last one produced cost about $47000 I have been told. This, along with fuel costs, is why flight training far exceeded economic inflation and the cost of the aircraft is almost entirely due to greed! Product liability insurance costs skyrocketed because of ridiculous damage awards from the courts, a low time non-instrument rated pilot could take off in a rain storm or heavy fog then when he got disoriented and crashed it was the airplane manufacturers fault! Those high costs can mostly be blamed on corporate lawyers and juries made up of non-flyers who know nothing about aircraft.


BTW, I got my rotocraft rating in a buddy's Hughs 300C and all it cost me was what I paid the instructor. :-D

That sounds about right on the 150. The numbers I remember were a little higher at the end of production. The FAA isn't helping General Aviation either. The higher cost of complying with regulations that, IMHO, don't enhance safety that much and will eventually drive out all but the wealthiest aircraft owners. The days of a blue collar guy being able to fly are all but gone.
I hold a Repair Station Certificate and my paperwork load tripled in 03 when the Feds changed all of the Part 145 regulations. They came in and said that your certificate would be terminated if you didn't basically revamp everything to the new rules within one year. Of course even the guys responsible for enforcement didn't understand the new regs and they had 2 or 3 extensions so they could get those guys up o speed. Glad that I'm close to retirement and don't have to worry about it much longer.

Bob

[Capn Jack]

An interesting aircraft I worked on once..Canadair CL-44 (4 Eng.Turboprop)

It used flying control surfaces. each surface had flight tabs as well as control tabs. The entire system was a series of "Push-Push" rods. The cockpit controls thru a system of levers pushed on the rods which in tern operated the flight tabs, which flew the control surfaces. As the pilot was only "Flying" a comparatively small tab the system had an artificial feel system to prevent over controlling.

Also because there was no direct connection needed between the "Push Rods" the entire tail could be swung to one side and cargo loaded straight in from the rear.

Darnedest thing you ever saw sitting on the apron, with both ailerons hanging
down, the tail open and one elevator up and the other down.

Jack...8-)

[MtGun44]

The Airbus newer models have no significant "feel". The side sticks apparently move
extremely little.

This was a big factor in the Airbus crash into the Atlantic a couple years ago. One of the
pilots continuously held back on the stick, keeping the aircraft stalled but the other
pilot, who had told him repeatedly to let off on the stick, could'nt tell that he was doing
it either visually or from his stick on his side.

It could not have happened in a Boeing because they still use yokes that move and
it would be very obvious to the other pilot by both looking, and because his yoke would
be moving the same way. He could have stopped the fool from killing them all.

As to the original question - Boeing definitely uses artificial feel, the purpose is to let the
pilot feel what he is doing to the aircraft. You can pull the wings or tail off if the controls
are too light, unless the flight control system artificially limits the loads, which Airbus does.
I'm sure that Boeing does at some point in the newer ones, but they primarily use feedback
forces in the yoke (what you called the steering wheel) to keep the aircraft intact.

Bill

[Recluse]

It could not have happened in a Boeing because they still use yokes that move and
it would be very obvious to the other pilot by both looking, and because his yoke would be moving the same way.

Bill

Old Air Force line from my day. . . "If it's not Boeing, I'm not going."

:coffee:

[Matt_G]

Old Air Force line from my day. . . "If it's not Boeing, I'm not going."

:coffee:
The one that stands out in my mind the most is:
"Take-offs are optional; landings are mandatory." [smilie=f:

[Alan in Vermont]

The three most useless things to a pilot?

Altitude above him.

Runway behind him.

Fuel, on the ground.

[oldred]

The one that stands out in my mind the most is:
"Take-offs are optional; landings are mandatory." [smilie=f:



I worked with a guy some years back that was an Army ranger back in the early 70's, he had never been in an airplane until joining the military and being in airborne he had not only had the odd experience of jumping out of the first airplane he ever flew in he said he experienced eleven take-offs before he experienced his first landing in an airplane!

[3006guns]

Hollywood. Same reason the foley editor always, and without fail, adds a "brake squeal" soundbyte to every scene in which a car slows to a normal stop: We're programmed to expect it, and it adds to the effect.

Gear

Or the squealing of tires in a high speed turn.........on dirt or gravel.:bigsmyl2:

Like my Dad told me when I was a very little boy, trembling at the sight of King Kong on our black and white T.V........."Its all make believe son, just make believe."

[Phillip]

Have you looked into your eligibility for a sport-pilot (LSA) certificate?

LSAs have some restrictions on them, but as I get older, the restrictions really bother me less--no IFR, no night flying, no speeds above 140kts (that one kind of stings), no Class B, etc.

I wouldn't/won't miss any of that stuff at all. :)

It's worth checking out.

:coffee:

Funny, I was looking into see what it takes to get a sport pilots certificate, and it seems to be pretty much straight forward and half the cost (about 3K).

But the one thing that surprised me, was once you get the certs that require you to get a physical you are screwed if you fail it, even though you can still drive.

That really surprised me and seems to be one of dumbest things they could have done to the older pilots.

[Boz330]

I worked with a guy some years back that was an Army ranger back in the early 70's, he had never been in an airplane until joining the military and being in airborne he had not only had the odd experience of jumping out of the first airplane he ever flew in he said he experienced eleven take-offs before he experienced his first landing in an airplane!

My first airplane ride was also my first jump. I had 40+ jumps before ever landing with an airplane, scared the Bejesus out of me. Full flap landing over power lines into a short grass strip.

Bob

[popper]

C-140, $10/hour w/instructor(who liked to do practice strafing runs in the jenny(T-28?), UNDER the power lines.. 500 hr TaylorCraft - $600. Unfortunately I has to pass on NavCad pilot training as I'm color blind. Brother-in-law got a kick out of pulling a full power stall in a '47 on his check pilot. They all use computer driven servos now. the stick just tells the computer what to do and the computer executes it safely (we hope). Yes, the yoke is spring loaded so it doesn't flop around.

[Recluse]

Funny, I was looking into see what it takes to get a sport pilots certificate, and it seems to be pretty much straight forward and half the cost (about 3K).

But the one thing that surprised me, was once you get the certs that require you to get a physical you are screwed if you fail it, even though you can still drive.

That really surprised me and seems to be one of dumbest things they could have done to the older pilots.

Yep, that's why older pilots are getting "pre-medicals" from physicians other than an AME. That we, if they pass the physical, they can go to their AME and have the official FAA physical done, pass it and continue flying.

If they fail the "pre-medical," then they simply opt to let their medical expire, then convert over to a sport pilot and use their drivers license as the "medical" and then abide by LSA FARs.

:coffee:

[Boz330]

Yep, that's why older pilots are getting "pre-medicals" from physicians other than an AME. That we, if they pass the physical, they can go to their AME and have the official FAA physical done, pass it and continue flying.

If they fail the "pre-medical," then they simply opt to let their medical expire, then convert over to a sport pilot and use their drivers license as the "medical" and then abide by LSA FARs.

:coffee:

Pretty ridicules when you think about it. You don't need a medical for Balloons or Gliders.
My AME was a B-17 pilot in WWII. His Military Flight certificate is on the wall in his office, signed by Capt Robert Hoover. I asked him about it and he said look at the date and explained they gave him his official flight certificate after he had been flying missions for 2 years in Europe.:shock: He worked his way through medical school as a crop duster. Very interesting guy to talk to.

Bob

[JIMinPHX]

Come to think of it the absolute stupidest thing I think I have ever seen on tv involved a bullet, it was on a show from back in the 70's, can't remember the name, where a doctor removed a bullet from a gunshot victim and then held it up for the investigating cop to see, it was the COMPLETE round case and all!!! :veryconfu

...must have been fired from a sling shot.:roll:

That's right up there with Barnaby Jones running down some 16 year old punk in sneakers & catching him, or Cannon ducking a rifle shot taken by a sniper with a big scope from up on a ridge, then returning fire with his snub nose revolver & getting the thug with his first shot. Ahhh, the magic of Hollyweird.

Seriously though,
Even in a fully fly by wire plane that has no tactile feedback in the stick, if you try to pull out of a steep dive or make a sharp turn, the G-forces will give you plenty to fight. Less than 3 g's during a training maneuver in a C-150 nearly put my lights out. The military guys see a lot worse than that on a regular basis. Even in a G-suit, they have a plenty-fierce fight on their hands when they make a steep maneuver. The envelope of the plane usually far exceeds the envelope of its operator. That part is no joke.