Airbus Rudder Failure (last Sunday) - Page 2

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[ARCHIVED THREAD] - Airbus Rudder Failure (last Sunday) (Page 2 of 2)

Posted: 3/12/2005 1:11:15 AM EDT

[#1]

Aero E- Rodent is right, and besides, if you are a pilot, you understand that you avoid wake turbulence. Period. Arguing whether or not a 757 has greater wake turbulence is pointless if you are staring at the ground inverted at 100 agl, wondering wtf just happened.

Don't pretend to know everything there is to know about air and aerodynamics. A lot of pilots have learned the hard way that there are always lessons to be learned.

Posted: 3/12/2005 3:06:03 AM EDT

[#2]

Quoted:
The last Marine pilots I met couldn't convert the true course to a target to a magnetic heading and wanted the FAC's to do it for them. I still haven't met a gray headed captain that remembers how to calculate weight and balance. My flying experience doesn't include jet time (except the sim domes at work, not the same), just night mail, pipeline patrol, tugging shit, recreational aerobatics, gliders, and even some DC-3 time.

You've never flown a fighter, but you're denigrating fighter pilots? You've never flown an airliner, but you're condescending to airline captains? I'm surprised you didn't tell us what child's play it is to land on an aircraft carrier. How about this - if we need any advice from a Piper Cub pilot about doing 500 knots on the deck to a target, or making a category III landing in a snowstorm at night, we let you know, okay? And here's a little aviation advice back at you: You'll become a better pilot and probably live longer if you shut up and listen once in a while.

Posted: 3/12/2005 3:06:49 AM EDT

[#3]

dont need no stinkin rudder anyways

Posted: 3/12/2005 4:39:31 AM EDT

[#4]

.

Posted: 3/12/2005 4:44:53 AM EDT

[#5]

Quoted:
Aero E- Rodent is right, and besides, if you are a pilot, you understand that you avoid wake turbulence. Period. Arguing whether or not a 757 has greater wake turbulence is pointless if you are staring at the ground inverted at 100 agl, wondering wtf just happened.

Don't pretend to know everything there is to know about air and aerodynamics. A lot of pilots have learned the hard way that there are always lessons to be learned.

I don't pretend to know it all, but I do know a hell of lot more than the average reader of Flying or AOPA Pilot.

Posted: 3/12/2005 4:48:51 AM EDT

[#6]

Actually the AA flight was following a JAL 747-400 on it's way to NRT. 757's and heavys do normally create large wake vorticies, and when you add a winglet on the end of the wing, multiply the wake vorticies by 1.5-2.5x

Posted: 3/12/2005 6:06:40 AM EDT

[#7]

Quoted:
I don't pretend to know it all, but I do know a hell of lot more than the average reader of Flying or AOPA Pilot.

Seems to me that you ARE pretending to know it all.

I have this mental image of you swaggering into the bar at Topgun and with a Cessna 150 patch on your flight suit, and impressing the shit out of all those ignorant jet pilots.

Posted: 3/12/2005 6:11:55 AM EDT

[#8]

Quoted:
Old wive's tale, based on anecdotal evidence... Everyone gets the warning behind all heavy aircaft; "Superplane 15 kilo, approved to land number 2 behind the 737 (or A320, or Super Connie, ad naseum). Caution wake turbulence."

Your ignorance is showing. Neither 737's, A320's nor Super Connies are heavies. And they don't say "approved to land", it's "cleared to land".

Posted: 3/12/2005 6:14:49 AM EDT

[#9]

Quoted:
Boeing and MD have both had rudder problems as well. Remember the 737s and their rudder actuators. The MD-9 series of aircraft had problems with their jackscrews. However, both problems could have been avoided if those parts were serviced and inspected on a regular basis. They do it now I bet.

The DC9/MD80 series had problems with their pitch trim actuators, not rudders. Their rudders are limited as airspeed increases to about 2 degrees in cruise flight. Full deflection (17 degrees if I remember right) can be had at slow speeds for landing. I never maintained Boeing airliners but the DC9 is one heck of a soundly designed airplane.

Posted: 3/12/2005 6:18:35 AM EDT

[#10]

Quoted:
The last Marine pilots I met couldn't convert the true course to a target to a magnetic heading and wanted the FAC's to do it for them.

Pardon, your ignorance is showing again. The FAC should have given them the magnetic course in the first place, as aircraft don't use true courses. A pilot terrain masking on the deck inbound to a target is what we call (pardon the technical aviation term) "busy". Not exactly the place to pull out a map, check the magnetic deviation, and do extra math.

Edited to add that I was a FAC as well as a Marine F4 and A4 pilot.

Posted: 3/12/2005 6:20:45 AM EDT

[#11]

Quoted:
I don't pretend to know it all, but I do know a hell of lot more than the average reader of Flying or AOPA Pilot.

Um, I'm thinking probably not.

Posted: 3/12/2005 6:45:19 AM EDT

[#12]

The jackscrews on the MD-80's are for the tailtrim (moving the entire elevator assembly) (nothing to do with the rudder)and were having problems because the maintenance types were using the wrong grease or not enough grease.

The 737 maximum rudder deflection is approximately +/-15 degrees on the ground, reducing to around +/-8 degrees at a typical cruise altitude.

Quoted:
Boeing and MD have both had rudder problems as well. Remember the 737s and their rudder actuators. The MD-9 series of aircraft had problems with their jackscrews. However, both problems could have been avoided if those parts were serviced and inspected on a regular basis. They do it now I bet.

Posted: 3/12/2005 7:28:44 AM EDT

[#13]

Quoted:
Quoted:
I don't pretend to know it all, but I do know a hell of lot more than the average reader of Flying or AOPA Pilot.

Um, I'm thinking probably not.

Hmm, and aeronautical engineer working for McBoeing. My guess is he knows more about the forces invovled than most on this board.

Posted: 3/12/2005 7:42:40 AM EDT

[#14]

Quoted:
Quoted:
Quoted:
I don't pretend to know it all, but I do know a hell of lot more than the average reader of Flying or AOPA Pilot.

Um, I'm thinking probably not.

Hmm, and aeronautical engineer working for McBoeing. My guess is he knows more about the forces invovled than most on this board.

He might be the world's greatest engineer, but he's not a very experienced pilot. Most of the stuff he's pompously pontificating about is just plain wrong.

Posted: 3/12/2005 7:55:58 AM EDT

[#15]

I'd agree with Rodent... There are the guys who design them and there are the guys who fly them. They both deal with the same beast but their experiences are going to vary greatly...

Spooky

Posted: 3/12/2005 8:01:39 AM EDT

[#16]

Quoted:
I'd agree with Rodent... There are the guys who design them and there are the guys who fly them. They both deal with the same beast but their experiences are going to vary greatly...

Spooky

Which is kinda my point when it comes to vertices and the like.

Let's put it in gun terms. An engineer can tell you that two guns in different calibers have the same recoil impulse. It will be true mathmatically; however, a shooter might describe one gun as having a "snappy" recoil, while the other a "push" recoil. Both perspectives would be true.

How many times have we seen advisories to make people feel better because of the perception even though in actuality there is no difference except with the perception? AWB ring a bell?

Posted: 3/12/2005 8:14:40 AM EDT

[#17]

Quoted:
Quoted:
I'd agree with Rodent... There are the guys who design them and there are the guys who fly them. They both deal with the same beast but their experiences are going to vary greatly...

Spooky

Which is kinda my point when it comes to vertices and the like.

Let's put it in gun terms. An engineer can tell you that two guns in different calibers have the same recoil impulse. It will be true mathmatically; however, a shooter might describe one gun as having a "snappy" recoil, while the other a "push" recoil. Both perspectives would be true.

Let's suppose the engineer knows everything there possibly is to know about metalurgy or pressure curves or whatever his particular field of expertise is. But let's suppose he's done very little actual shooting. He may have popped off a few rounds from a few different rifles. Is he now an unassailable marksmanship expert ready to critique the winners of Wimbledon? He would do well to listen and learn once he gets outside his area of expertise, rather than condescendingly denigrating the people who actually do what he only reads about.

Posted: 3/12/2005 8:20:17 AM EDT

[#18]

Quoted:
Let's suppose the engineer knows everything there possibly is to know about metalurgy or pressure curves or whatever his particular field of expertise is. But let's suppose he's done very little actual shooting. He may have popped off a few rounds from a few different rifles. Is he now an unassailable marksmanship expert ready to critique the winners of Wimbledon?

No. But just because a metalurgist doesn't engage in sword fights doesn't mean he can't tell you about the tensile strength of the steel used to make the swords.

Again, I'm not saying AeroE knows anything about the techniques of flying. I was just saying as an engineer he has an understanding of the forces involved. Perhaps, more knowledge about the forces than most, including pilots. However, just because one understands how something works doesn't make one an expert at its operation. I have never argued that.

Posted: 3/12/2005 8:27:53 AM EDT

[#19]

Quoted:
But just because a metalurgist doesn't engage in sword fights doesn't mean he can't tell you about the tensile strength of the steel used to make the swords.

Again, I'm not saying AeroE knows anything about the techniques of flying. I was just saying as an engineer he has an understanding of the forces involved. Perhaps, more knowledge about the forces than most, including pilots. However, just because one understands how something works doesn't make one an expert at its operation. I have never argued that.

I don't know what AeroE's area of expertise is, but it sure isn't flying. I felt obliged to correct the most glaringly ignorant of his posts. Pretenders annoy me, I guess. Like I said, he might be the finest engineer to ever walk the face of the earth, but...

Posted: 3/12/2005 8:39:52 AM EDT

[#20]

Quoted:
Quoted:
But just because a metalurgist doesn't engage in sword fights doesn't mean he can't tell you about the tensile strength of the steel used to make the swords.

Again, I'm not saying AeroE knows anything about the techniques of flying. I was just saying as an engineer he has an understanding of the forces involved. Perhaps, more knowledge about the forces than most, including pilots. However, just because one understands how something works doesn't make one an expert at its operation. I have never argued that.

I don't know what AeroE's area of expertise is, but it sure isn't flying. I felt obliged to correct the most glaringly ignorant of his posts. Pretenders annoy me, I guess. Like I said, he might be the finest engineer to ever walk the face of the earth, but...

Look I'm not defending anyone, but criticisms like "I don't know what AeroE's area of expertise is, but it sure isn't flying," could be made of ANYONE. Hell, he could come here and ask how many aircraft systems you've designed, and level the criticism "I don't know what Rodents area of expertise is, but it sure isn't system design."

To me, it is interesting to be able to read a pilot's perspective vs and engineer's perspective. I agree with Spooky130 and his comment about experiences.

Posted: 3/12/2005 8:52:49 AM EDT

[#21]

Quoted:
Look I'm not defending anyone, but criticisms like "I don't know what AeroE's area of expertise is, but it sure isn't flying," could be made of ANYONE. Hell, he could come here and ask how many aircraft systems you've designed, and level the criticism "I don't know what Rodents area of expertise is, but it sure isn't system design."

If I had entered this thread and pretended to know something I didn't, then he would be justified in making such a retort.

If you go back and carefully read both his posts and mine, I think you'll find that you and I are in agreement.

Posted: 3/12/2005 9:29:45 AM EDT

[#22]

Quoted:
The jackscrews on the MD-80's are for the tailtrim (moving the entire elevator assembly) (nothing to do with the rudder)and were having problems because the maintenance types were using the wrong grease or not enough grease.

The 737 maximum rudder deflection is approximately +/-15 degrees on the ground, reducing to around +/-8 degrees at a typical cruise altitude.
www.b737.org.uk/faaillo.gif

Quoted:
Boeing and MD have both had rudder problems as well. Remember the 737s and their rudder actuators. The MD-9 series of aircraft had problems with their jackscrews. However, both problems could have been avoided if those parts were serviced and inspected on a regular basis. They do it now I bet.

Yes I know that jackscrews are for moving the tailplane as in the Alaskan airlines plane that went down near California. But it just goes to show airplanes are complex machines and need maintnance. And even sound designs show their age eventually.

Posted: 3/12/2005 2:04:23 PM EDT

[#23]

Here's what we know about Rodent - he's whiny. I won't debate my flying or engineering skill and experience with a bus driver, ex fighter pilot or not.

When I get to work next week I'll look around in the company intranet to see what reports I can find. The point is that no one knows absolutely whether 757 wake caused these accident but it is probably a contributing factor; the FAA has a policy of extra caution, and pilots are rightly choosing caution.

BTW it's "cleared to land"; dumb fucking mistake, and I know better.

Posted: 3/12/2005 3:18:19 PM EDT

[#24]

Two of my whiney former Marine fighter pilot friends and our token whiney former Marine infantry officer friend are stopping over tonight. In between bouts of whining, we'll drink a toast to your skill and courage.

Posted: 3/12/2005 3:59:27 PM EDT

[#25]

I thought the deal with the 757 was that it is just under the limit for being called "heavy," and so it doesn't get the extra mandatory spacing heavies are given for their vortices, even though it effectively generates vortice as powerful as a "heavy."

Posted: 3/12/2005 4:09:52 PM EDT

[#26]

Quoted:
Two of my whiney former Marine fighter pilot friends and our token whiney former Marine infantry officer friend are stopping over tonight. In between bouts of whining, we'll drink a toast to your skill and courage.

Sounds like a Whine Fest.

Posted: 3/12/2005 4:22:21 PM EDT

[#27]

Yup, but that's what makes ARFcom so much fun

Posted: 3/12/2005 4:24:45 PM EDT

[#28]

Amen, my brother. It's an addictive combination of good advice, BS and entertainment.

Posted: 3/12/2005 4:41:37 PM EDT

[#29]

Perfect description... Sometimes a little heavy on BS!

Posted: 3/12/2005 4:58:36 PM EDT

[#30]

Hehehe, I could say the same thing about pilots and engineers who think they know how to fix aircraft...

Quoted:
I don't know what AeroE's area of expertise is, but it sure isn't flying. I felt obliged to correct the most glaringly ignorant of his posts. Pretenders annoy me, I guess. Like I said, he might be the finest engineer to ever walk the face of the earth, but...

Posted: 3/12/2005 5:05:51 PM EDT

[#31]

In the three years flying the C-5, I've seen one pilot actually fix the airplane when the engineers and maintenance folks were baffled - with a plastic spoon even! I go find a nice place to sit, out of the way, while maintenance does their thing. I'm only paid to break 'em, not fix 'em...

Posted: 3/12/2005 9:11:20 PM EDT

[#32]

Quoted:
I thought the deal with the 757 was that it is just under the limit for being called "heavy," and so it doesn't get the extra mandatory spacing heavies are given for their vortices, even though it effectively generates vortice as powerful as a "heavy."

Almost right. The 757 is under the weight limit for being called a heavy, but it does get the same mandatory spacing as a heavy, due to the larger than normal vortices it develops.

The wake effect on trailing aircraft depends on many variables in the atmosphere that change by the minute. That is what makes it so hard to predict.

IOW, a 737 5 miles in front might be more dangerous then a 747 5 miles in front, depending on atmospheric stabilitly, crosswind, etc.

aero-e probably knows this, but still chose to argue semantics, Rodent took issue because he knows that there is a lot more to flying than what slide rules, calculators, or even an E6B will tell you.

IMHO, the AA crash happened because of a combination of bad french engineering, and a twitchy co-pilot. The accident aircraft developed destructive loads on the rudder as a result of fairly light pressure applied to the rudder pedals in sequence.

1. It was flying below manuevering speed. The engineers, the FAA, and the Airlines always taught that you should not be able to overstress an aircraft below VA

2. The fly by wire computers on an airbus are supposed to prevent the pilot from overcontrolling.

3. The co-pilot should not have cycled the rudders as the FDR indicates he did. In transport aircraft, you fly with your feet off the rudder unless performing a V1 cut, crosswind landing or recovery from an unusual attitude. In any case, one should always be gentle and smooth.

As in the case of TWA800, I'm not fully convinced that the ROP wasn't somehow at fault.

Posted: 3/12/2005 9:17:31 PM EDT

[#33]

Quoted:
Two of my whiney former Marine fighter pilot friends and our token whiney former Marine infantry officer friend are stopping over tonight. In between bouts of whining, we'll drink a toast to your skill and courage.

Hey Rodent, dont worry, I know where you are coming from. Former Marine pilot turned AA 757/767 pilot is what my dad is......

Flew with VMFA-112 from '86 till 2001 in the Phantom and Hornet, and now he is a check airmen on the 757/767 working in the school house and the line....Perhaps you have met him. Callsign is "Shed"

Posted: 3/12/2005 10:51:47 PM EDT

[#34]

I will say this though, they don't call them Scarebuses with out good reason.

Finest aircraft ever built IMHO.

Posted: 3/13/2005 3:13:45 AM EDT

[#35]

Quoted:
In the three years flying the C-5, I've seen one pilot actually fix the airplane

As Donald Sutherland said in "Kelly's Hero's", "I just drive 'em, I don't know what makes 'em go."

Posted: 3/13/2005 3:16:32 AM EDT

[#36]

Quoted:
Quoted:
Two of my whiney former Marine fighter pilot friends and our token whiney former Marine infantry officer friend are stopping over tonight. In between bouts of whining, we'll drink a toast to your skill and courage.

Hey Rodent, dont worry, I know where you are coming from. Former Marine pilot turned AA 757/767 pilot is what my dad is......

Flew with VMFA-112 from '86 till 2001 in the Phantom and Hornet, and now he is a check airmen on the 757/767 working in the school house and the line....Perhaps you have met him. Callsign is "Shed"

I flew with VMFA 235, and left active duty in '86, so I just missed him. I'm thinking about bidding the 757 to Europe next (Boston just got the route to Shannon), so maybe our paths will cross.

Posted: 3/13/2005 3:22:24 AM EDT

[#37]

Quoted:
aero-e probably knows this, but still chose to argue semantics, Rodent took issue because he knows that there is a lot more to flying than what slide rules, calculators, or even an E6B will tell you.

Actually, I took issue with his condescending attitude about fighter pilots and airline captains, coupled with his obvious lack of flying experience. Struck me as a pompous ass with a self-esteem problem.

Posted: 3/13/2005 5:12:52 AM EDT

[#38]

Quoted:
I will say this though, they don't call them Scarebuses with out good reason.

Finest aircraft ever built IMHO.

www.air-and-space.com/19861225%20LAX/861672%20L-1011%20N725DA%20Delta%20take-off%20m.jpg

A very big +1!………

They're the backbone of the Royal Air Forces Tanker Fleet. The pilots love that plane, pure class, nothing else comes close.

ANdy

Posted: 3/14/2005 8:42:08 PM EDT

[#39]

hope this works, pics in "my gallery" are looking all fucked up.

just two pics to show turbulance after the 1st plane is gone from view.

Posted: 3/14/2005 8:43:51 PM EDT

[#40]

Quoted:
hope this works, pics in "my gallery" are looking all fucked up.

just two pics to show turbulance after the 1st plane is gone from view.

photos.ar15.com/ImageGallery/Attachments/DownloadAttach.asp?iImageUnq=10982

photos.ar15.com/ImageGallery/Attachments/DownloadAttach.asp?iImageUnq=10983

But all the data says there is not supposed to be any turbulance. Its just anecdotal!

Posted: 3/14/2005 9:03:12 PM EDT

[#41]

Quoted:
Quoted:
Quoted:
Two of my whiney former Marine fighter pilot friends and our token whiney former Marine infantry officer friend are stopping over tonight. In between bouts of whining, we'll drink a toast to your skill and courage.

Hey Rodent, dont worry, I know where you are coming from. Former Marine pilot turned AA 757/767 pilot is what my dad is......

Flew with VMFA-112 from '86 till 2001 in the Phantom and Hornet, and now he is a check airmen on the 757/767 working in the school house and the line....Perhaps you have met him. Callsign is "Shed"

I flew with VMFA 235, and left active duty in '86, so I just missed him. I'm thinking about bidding the 757 to Europe next (Boston just got the route to Shannon), so maybe our paths will cross.

Cool. He flew active duty from 81-86, with VMFA 451 and some other squadrons too. Sorry about your squadron, they all seem to disappear.

Posted: 3/15/2005 10:07:58 AM EDT

[#42]

Quoted:
If it ain't Boeing, I ain't going.

+1

"Refuse Toulouse! Get Boeing!"

Posted: 3/15/2005 10:19:26 AM EDT

[#43]

Quoted:
Quoted:
I don't think you want to be a passenger in the outer wing of a span loaded flying wing.

Flying wings require a careful design trade - there is so much wetted area that it can easily offset the advantage of deleting the empennage. Plus, pressurized tubes are efficient shapes for pressurization, flat sided compartments and so on that get pressurized are very heavy.
Oh, yeah, what do you know? What do you think you are, some kind of Aerospace Engin ... oh, wait.

Yes, I'm a little aware of the myriad difficulties involved in the design of a large civil flying wing. I was just trying to illustrate that for many things, there are a number of solutions. Some are elegant in their simplicity.

Boeing BWB, anyone?

Quoted:
Quoted:
The jackscrews on the MD-80's are for the tailtrim (moving the entire elevator assembly) (nothing to do with the rudder)and were having problems because the maintenance types were using the wrong grease or not enough grease.

Yes I know that jackscrews are for moving the tailplane as in the Alaskan airlines plane that went down near California. But it just goes to show airplanes are complex machines and need maintnance. And even sound designs show their age eventually.

From the Seattle Times articles on the Flight 261 crash, the problem was not the "wrong grease", it was that Alaska Air was putting off required maintenance and firing mechanics who insisted that it was damn well time to replace the worn-out parts. The jackscrew on 261 was supposedly tested about a year before it self-destructed and was initially found to be past due for replacement, then the supervisors insisted that the mechanics test and re-test until they found it was "still within specs" so that it could go for another 18 months.

[ARCHIVED THREAD] - Airbus Rudder Failure (last Sunday) (Page 2 of 2)

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