AF 447 Search to resume
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mm43
Let me go ahead and answer my own question, you may not have read my admission to Machaca that I ask questions sometimes to give whomever reads this a chance for better understanding with a second viewpoint. It's slightly deceptive, and I'm irritating myself with it at this point. "Arm36g" is single, composed of Aluminum alloy, probably hardened after pull extrusion, and it has a big hole in it where a bolt penetrates it to fasten it to the Rudder's Steel hinge cylinder (Barrel) (Please let it be steel ). If this is a Thru-bolt, I see the symmetry.
This is an asymmetrical approach to a solution for lateral retention. The Tip failed, it is missing. Why is this important?
1. It failed in tension, but only ostensibly. Using the word "Fracture" determines this.
2. The stress it transmits to the Rudder is asymmetrical, causing a torsion that would be obviated by a sister on the other side.
3. To fail in tension, the Hinges would have to have deflected enough to allow the "travel" through to the arm to cause separation at the center cross section of the arm's attachment (Bolt).
4. The bolt is bedded in resin or sealant, and appears NOT to have "bent" due to stretching at the arm. (Tensing)
5. The bolt is "undisturbed" it is likely the arm failed through either weakening by corrosion, or the tip fell off prior to this flight, since there is no evidence to conclude the failure was due impact.
6. Aluminum as a tensile member? Draw one's own conclusions.
Longitudinal support through to Frame 76? Not really. There is no support other than the HOOP (Frame). The frame is not visually different from either Machaca's photo, or the other diagrams. It is unremarkable forward of the 1A1B join, and the assumption is the Frames are similar in manufacture the length of the Fuse. As they gather the longerons for a matrix to bed the skin to, they are stressed for that task, there is no visual evidence the joins were supported other than by mere attachment to the HOOPS, more a liability to the Hoop than additive strength for the Bracket.
imo. Please continue, your grasp (and Machaca's, and HazelNuts39's) of the discussion is nails, and I feel the commentary is coalescing. imo.
Let me go ahead and answer my own question, you may not have read my admission to Machaca that I ask questions sometimes to give whomever reads this a chance for better understanding with a second viewpoint. It's slightly deceptive, and I'm irritating myself with it at this point. "Arm36g" is single, composed of Aluminum alloy, probably hardened after pull extrusion, and it has a big hole in it where a bolt penetrates it to fasten it to the Rudder's Steel hinge cylinder (Barrel) (Please let it be steel ). If this is a Thru-bolt, I see the symmetry.
This is an asymmetrical approach to a solution for lateral retention. The Tip failed, it is missing. Why is this important?
1. It failed in tension, but only ostensibly. Using the word "Fracture" determines this.
2. The stress it transmits to the Rudder is asymmetrical, causing a torsion that would be obviated by a sister on the other side.
3. To fail in tension, the Hinges would have to have deflected enough to allow the "travel" through to the arm to cause separation at the center cross section of the arm's attachment (Bolt).
4. The bolt is bedded in resin or sealant, and appears NOT to have "bent" due to stretching at the arm. (Tensing)
5. The bolt is "undisturbed" it is likely the arm failed through either weakening by corrosion, or the tip fell off prior to this flight, since there is no evidence to conclude the failure was due impact.
6. Aluminum as a tensile member? Draw one's own conclusions.
Longitudinal support through to Frame 76? Not really. There is no support other than the HOOP (Frame). The frame is not visually different from either Machaca's photo, or the other diagrams. It is unremarkable forward of the 1A1B join, and the assumption is the Frames are similar in manufacture the length of the Fuse. As they gather the longerons for a matrix to bed the skin to, they are stressed for that task, there is no visual evidence the joins were supported other than by mere attachment to the HOOPS, more a liability to the Hoop than additive strength for the Bracket.
imo. Please continue, your grasp (and Machaca's, and HazelNuts39's) of the discussion is nails, and I feel the commentary is coalescing. imo.
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Hi,
Hope nobody minds me asking a question.
If the recorders are to be found in another search effort what are the chances of getting usable data out of them? Is the data stored of a disc of some sort or in RAM type memory?
d747
Hope nobody minds me asking a question.
If the recorders are to be found in another search effort what are the chances of getting usable data out of them? Is the data stored of a disc of some sort or in RAM type memory?
d747
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bearfoil:
Brawn is much more than skin deep!
Just the female lugs that are situated between and joined to the massive frames (not mere hoops) are each 82 kg of forged AlZn5.5MgCu/(B).
Here's how the frames for the (smaller) A400M appear:
You can get a glimpse of them within A6-ERG's (Melbourne tailstrike) section 19:
...there is no visual evidence the joins were supported other than by mere attachment to the HOOPS...
Just the female lugs that are situated between and joined to the massive frames (not mere hoops) are each 82 kg of forged AlZn5.5MgCu/(B).
Here's how the frames for the (smaller) A400M appear:
You can get a glimpse of them within A6-ERG's (Melbourne tailstrike) section 19:
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Machaca
First, Sir, let me catch my breath. That pic is exquisite. You have what I envy, the ability to allow something (or someone) to do the talking. I am humbled.
I am also embarrassed! Unfortunately, that will soon pass. The assembly impresses!
Back to critique. The strength (speaks for itself), only further dissociates the focal and concentrated assemblage's beauty. How is this wonder accepted by the Fuselage?
How is the stress (even of the sheer weight of the structure) spread ? The standard solution to 'Tube' is Frame, longeron, skin, and is not meant to support 'anything'. By photograph, this is evident at the structure forward of the first join, where the massive approach abruptly terminates into Tube? When a/c were constructed in one massive hangar, the need for this Weight, Stress, Solution took shape in Blended support.
If the (587) Rudder had been snubbed to prevent over control in Yaw, well.........
The Fuse/VS structure is Independent of the whole, it requires "attachment"
Weak link and all that.....? Any break in stress/response (join) is a "designed" Fracture, by definition. The Dreamliner is an expression of "whole" assembly, but a poor one.
The ultimate solution may be to assemble the entire A/C in a viscous amber and black goo, then bake it (in its entirety) in an as yet unbuilt oven, within 24 hours. Hah!
Resin/Fiber is mated structure to structure in ways that are far behind the potential of the airframe as a whole. Why? The answer is in Capitalism, Politics, and Geography.
I'm taking instruction in how to present my scratchy cocktail napkin drawings here, I can then write much less. Yo!
Back in the days of 587's loss, I tried to promote my idea of sequential Fin failure, top down ; divide the weight at the fuselage, (cut up that beautiful monster) into three (or four) "mates", such that the top and weakest mate failed and subtracted its contribution to Bending moment at the (587's) large mate. Shorten the Lever, as it were. Or, blow the Rudder off with explosive bolts at the Hinges, simples. What a nut? The Rudder jett is an extreme example of why the Rudder is a hangar on, it is not necessary for basic flight!!
bear
First, Sir, let me catch my breath. That pic is exquisite. You have what I envy, the ability to allow something (or someone) to do the talking. I am humbled.
I am also embarrassed! Unfortunately, that will soon pass. The assembly impresses!
Back to critique. The strength (speaks for itself), only further dissociates the focal and concentrated assemblage's beauty. How is this wonder accepted by the Fuselage?
How is the stress (even of the sheer weight of the structure) spread ? The standard solution to 'Tube' is Frame, longeron, skin, and is not meant to support 'anything'. By photograph, this is evident at the structure forward of the first join, where the massive approach abruptly terminates into Tube? When a/c were constructed in one massive hangar, the need for this Weight, Stress, Solution took shape in Blended support.
If the (587) Rudder had been snubbed to prevent over control in Yaw, well.........
The Fuse/VS structure is Independent of the whole, it requires "attachment"
Weak link and all that.....? Any break in stress/response (join) is a "designed" Fracture, by definition. The Dreamliner is an expression of "whole" assembly, but a poor one.
The ultimate solution may be to assemble the entire A/C in a viscous amber and black goo, then bake it (in its entirety) in an as yet unbuilt oven, within 24 hours. Hah!
Resin/Fiber is mated structure to structure in ways that are far behind the potential of the airframe as a whole. Why? The answer is in Capitalism, Politics, and Geography.
I'm taking instruction in how to present my scratchy cocktail napkin drawings here, I can then write much less. Yo!
Back in the days of 587's loss, I tried to promote my idea of sequential Fin failure, top down ; divide the weight at the fuselage, (cut up that beautiful monster) into three (or four) "mates", such that the top and weakest mate failed and subtracted its contribution to Bending moment at the (587's) large mate. Shorten the Lever, as it were. Or, blow the Rudder off with explosive bolts at the Hinges, simples. What a nut? The Rudder jett is an extreme example of why the Rudder is a hangar on, it is not necessary for basic flight!!
bear
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CVR - FDR recorders
It's not the present subject, but d747 wrote at # 2081
Nobody knows, but sometimes it's possible to recover unreadable data (click on 27/11/2008 Perpignan at the right corner of the page, and look at page 19).
If the recorders are to be found in another search effort what are the chances of getting usable data out of them? Is the data stored of a disc of some sort or in RAM type memory?
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Thanks, Machaca, for the mention of the material used in the VS clevises and their contiguous attachments to the frames (an AB 400, smaller submodel; do I have that right?). Are the frames in this area also metal?
This is the first time I have seen mention of the material from which key parts are fabricated. By "key", I mean parts from which the official reports have drawn conclusions. I think a substantial improvement in the usefulness of these reports could be made by including such information. I'll elaborate on the reason later.
Also let me thank Bearfoil, mm43, and possibly others who pointed out that a substantial discussion of the VS to rudder drag link (part 36g) was back at pages 19 to 30 or so in this thread (March+/-). I had a long-lasting problem on this computer thru that time, and have since been reading both forwards and backwards from the point where I returned.
Thanks too for some excellent enlarged photo clips of the drag link area. If they are from the report pictures, it was a lot more than I could do with my photo tools. I noticed in them something that suggests an alternate explanation for the fracture of that link-- that is, an alternate to a 36 g's impact with the water surface. I tend to agree with those who have said that the moderate degree of damage, to components spilled from the plane and recovered, suggests a lesser impact. But I'd prefer to finish reading all the earlier comments in this area before getting into that.
It would help to know the material of that link, part 36g. Was it metal or a fiber-reinforced plastic? Machaca?
Finally, I would say that I agree with PJ2 that the key lessons for the future will lie in answering the questions as to how this event began. However, I do think that questions about the strength of the fin and rudder will also be useful, given the history of problems in this area. At the moment, I lean toward the feeling that Airbus has given attention to this area; because to me the composites area of the fin showed considerable strength this time. But that's just a working premise noted in passing, presented as yet without the careful documentation often seen here.
OE
This is the first time I have seen mention of the material from which key parts are fabricated. By "key", I mean parts from which the official reports have drawn conclusions. I think a substantial improvement in the usefulness of these reports could be made by including such information. I'll elaborate on the reason later.
Also let me thank Bearfoil, mm43, and possibly others who pointed out that a substantial discussion of the VS to rudder drag link (part 36g) was back at pages 19 to 30 or so in this thread (March+/-). I had a long-lasting problem on this computer thru that time, and have since been reading both forwards and backwards from the point where I returned.
Thanks too for some excellent enlarged photo clips of the drag link area. If they are from the report pictures, it was a lot more than I could do with my photo tools. I noticed in them something that suggests an alternate explanation for the fracture of that link-- that is, an alternate to a 36 g's impact with the water surface. I tend to agree with those who have said that the moderate degree of damage, to components spilled from the plane and recovered, suggests a lesser impact. But I'd prefer to finish reading all the earlier comments in this area before getting into that.
It would help to know the material of that link, part 36g. Was it metal or a fiber-reinforced plastic? Machaca?
Finally, I would say that I agree with PJ2 that the key lessons for the future will lie in answering the questions as to how this event began. However, I do think that questions about the strength of the fin and rudder will also be useful, given the history of problems in this area. At the moment, I lean toward the feeling that Airbus has given attention to this area; because to me the composites area of the fin showed considerable strength this time. But that's just a working premise noted in passing, presented as yet without the careful documentation often seen here.
OE
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Those are pretty tough!
And most well-equipped investigating organisations such as BEA have equipment to take a smashed-up and water-logged recorder apart, to extract the memory circuit boards, to remove the individual memory packages if necessary, and if pillar really comes to post, to extract and read the actual memory chips.
So yes, IF the recorders are found, chances of getting usable data out of them are good.
Unless of course the recorders themselves lost power for some reason at an early stage....
CJ
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Machaca,
Yes! Great image. Makes you proud that we (humans) can design and build such exquisite structures. And make them fly!
The empennage parts are possibly sourced from Otto Fuchs KG in Meinerzhagen,
Germany; not sure where assembled. But I'm pretty sure that just the lovely precision tooling fixture supporting/aligning those frame stations cost more than my house and car combined.
Does make me wonder if bearfoil's thinking might be tested with the proper finite element analysis using engineering data already in the Airbus computer.
GB
Yes! Great image. Makes you proud that we (humans) can design and build such exquisite structures. And make them fly!
The empennage parts are possibly sourced from Otto Fuchs KG in Meinerzhagen,
Germany; not sure where assembled. But I'm pretty sure that just the lovely precision tooling fixture supporting/aligning those frame stations cost more than my house and car combined.
Does make me wonder if bearfoil's thinking might be tested with the proper finite element analysis using engineering data already in the Airbus computer.
GB
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Originally Posted by Old Engineer
It would help to know the material of that link, part 36g. Was it metal or a fiber-reinforced plastic?
In the context of Bearfoil's structural preferences, I would like to understand why the material is important. Whatever its material or method of manufacture, that part needs to be sized to support an ultimate load of 120,000 N, and a limit load of 80,000 N. The important evidence is that those design loads were exceeded.
regards,
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Folks,
some of us are very interested by what is said here, but very frustrated by the rhetoric. You are not just talking amongst yourselves. Can you please take into account in your contributions the lurkers who can read and digest the information already out there (ACARS messages plus observed damage from retrieved parts), and really want to know what happened, but don't think they can derive it from the available information?
PBL
some of us are very interested by what is said here, but very frustrated by the rhetoric. You are not just talking amongst yourselves. Can you please take into account in your contributions the lurkers who can read and digest the information already out there (ACARS messages plus observed damage from retrieved parts), and really want to know what happened, but don't think they can derive it from the available information?
PBL
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PBL
Your feelings on this matter are appreciated.
As Bearfoil has pointed out, his approach to the subject can possibly be categorized as "antagonistic", in the sense that he will rubbish the Airbus design concept and the BEA's investigation integrity in order to stir up a response. I can go along with that knowing that when all is "done and dusted" that the truth will emerge.
Other than that, this thread has produced a lot of useful information in relation to this accident, and somewhere within it will be various pieces that when all put together will match what really happened. Producing that necessarily involves a degree of technical rhetoric in order to put and contest the various theories propounded.
Until that final truth is revealed, I am sure that a good deal more discussion, be it classified as frustrating rhetoric or not, may help you and many others understand some of the complexities inherent in FBW aircraft and the environment they operate in.
It has helped me!
mm43
Your feelings on this matter are appreciated.
As Bearfoil has pointed out, his approach to the subject can possibly be categorized as "antagonistic", in the sense that he will rubbish the Airbus design concept and the BEA's investigation integrity in order to stir up a response. I can go along with that knowing that when all is "done and dusted" that the truth will emerge.
Other than that, this thread has produced a lot of useful information in relation to this accident, and somewhere within it will be various pieces that when all put together will match what really happened. Producing that necessarily involves a degree of technical rhetoric in order to put and contest the various theories propounded.
Until that final truth is revealed, I am sure that a good deal more discussion, be it classified as frustrating rhetoric or not, may help you and many others understand some of the complexities inherent in FBW aircraft and the environment they operate in.
It has helped me!
mm43
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mm43,
I feel I understand as well as anybody and far better than most what may have happened to AF 447 and how. I am very open, indeed keen, for new insight. Which I don't get when people who talk about ditching completely confuse the physical units they adduce. Akin to a violinist trying to play a Brahms Sonata but not being quite sure which of the four strings to tune to A=440.
PBL
I feel I understand as well as anybody and far better than most what may have happened to AF 447 and how. I am very open, indeed keen, for new insight. Which I don't get when people who talk about ditching completely confuse the physical units they adduce. Akin to a violinist trying to play a Brahms Sonata but not being quite sure which of the four strings to tune to A=440.
PBL
A=440 is almost history, by the way... found this on a violinist forum
(Played the violin in a symphony orchestra myself for 15 years when I was younger)... Anyway, I last wrote a post in this thread some 6 months ago, wishing them luck in finding the flight recorders. Iīm very disappointed that they havenīt so far.. but thatīs just the way it is for the moment.
Lots of orchestras tune to 442. According to a well known orchestral violinist I know, Boston Symphony Orchestra tunes to 444, NY Phil tunes to 443, and Berlin Phil tunes to 445. I personally really don't like 440 - I tune usually to 443 or 444 when I practice.
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PBL,
One of the remarkable properties of this public PPRunE thread has been its contributors' collective tolerance for the off-the-wall ideas that appear from time to time within what seems to be a rather disciplined atmosphere of good engineering, flight experience, and science.
With so few facts known about the AF447 upset, it seems to me that laying out on the examining table all possibilities and knowns in a grand mashup of theory (and perhaps rhetoric), then letting those ideas that withstand a "test of reasonableness" percolate to the top is a good approach. If you review this and the prior AF447 thread, I believe you will discover a certain springiness that continually returns the contributions to reasonableness. Unlike BEA, contributors here are not REQUIRED to reach a conclusion, yet they continue to work hard studying the mashup and seeking to understand the puzzle.
If I might expand your own metaphor, last time I was at the Philharmonie in Berlin (where my ladyfriend had a memorable coughing fit in the tight balcony tier far from an exit), the violinist tuned to A=443Hz. Though an ISO standard since 1955, A does not always equal 440Hz. This thread has had excellent contributions from aviation experts and others who know the standards and expected behaviors but will still ask "what if" and think outside of the box. Indeed, there has been very little bashing of manufacturers, authorities, third parties, or agencies, if that is what you mean by rhetoric.
GB
One of the remarkable properties of this public PPRunE thread has been its contributors' collective tolerance for the off-the-wall ideas that appear from time to time within what seems to be a rather disciplined atmosphere of good engineering, flight experience, and science.
With so few facts known about the AF447 upset, it seems to me that laying out on the examining table all possibilities and knowns in a grand mashup of theory (and perhaps rhetoric), then letting those ideas that withstand a "test of reasonableness" percolate to the top is a good approach. If you review this and the prior AF447 thread, I believe you will discover a certain springiness that continually returns the contributions to reasonableness. Unlike BEA, contributors here are not REQUIRED to reach a conclusion, yet they continue to work hard studying the mashup and seeking to understand the puzzle.
If I might expand your own metaphor, last time I was at the Philharmonie in Berlin (where my ladyfriend had a memorable coughing fit in the tight balcony tier far from an exit), the violinist tuned to A=443Hz. Though an ISO standard since 1955, A does not always equal 440Hz. This thread has had excellent contributions from aviation experts and others who know the standards and expected behaviors but will still ask "what if" and think outside of the box. Indeed, there has been very little bashing of manufacturers, authorities, third parties, or agencies, if that is what you mean by rhetoric.
GB
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The A400 has four pair of brackets, a 33% improvement in the context of the ultimate engineering goal in aeromanufacture. Please return to BEA photos of the brackets left attached to 447's VS. Then return to Machaca's image of the A400, then back, as many times as you need until you understand something about the challenge in accepting that the Fin "popped" out of its mounts due to injection into the substructure, followed by a slight torsion and a "buoyancy" impetus. I have not seen A320 Fin pictures closeup (Perpignan assessment flight).
447
10600 pounds of fuel in the THS. Upset at perhaps M.85, upset with wings level ?
Doubtful. Look at Perpignan. 20,000 hours between 1 and 2. Daylight, below ceiling of 3,000 feet, knows the ocean is there, climbs rolls, falls, climbs rolls past 97 degrees, all this in a volitional manoeuvre. Very ill advised, but. Someone else consider the floor, the RTLU, etc. I think 447 lost her tailfeathers after upset, after final ACARS, at altitude. Machaca's rotogravure gives a slight push. That jig bearing the siren sculpture, I agree, it is not your standard hard point rotisserie.
PBL I briefly mentioned a pilot in command considering a Ditch, but very early, and mostly as a prayer. Who else talks of Ditching? It is a fleeting thought, perhaps, but I think no one on board believed it in the realm.
Roll, no Bug, no Horizon, the nose is down, fix the roll fix the roll now pitch up slowly, slowly Airspeed Airspeed, Pitch up, no down, roll roll. All the way down. Another tragic Airbus, 587, had daylight, the standard issue spunky Rudder, and ended up inverted, rolling slowly. If she had been 100knots faster, at say 35k feet, she could not have even kept her svelte body in one piece. We are likely ignoring 447's THS at the expense of a better view. She kept it on descending in an airstream of perhaps 200 knots that was virtually 90degrees verse aerodynamic? Loaded with fuel, buffeted and changing drag quickly and heavily. With the kind of Pitch angle excursions in the Perpignan crash, the fully loaded tail would no more withstand separation than 587 did her VS/Rudder. It articulates, and has "Rudders" with better loading than the actual Rudder. Changing from 50 degrees up to 19 degrees down, (Perpignan) is virtually 70 degrees of sweep. Protections?
GreatBear To travel to "likely" involves a bonfire of the vanities through the Possible, and even the ridiculous. It is necessary to goad with the impossible those who defend the unkown, those who don't want to know, or stand to write big checks if Pollyanna really is full of crap.
bear
447
10600 pounds of fuel in the THS. Upset at perhaps M.85, upset with wings level ?
Doubtful. Look at Perpignan. 20,000 hours between 1 and 2. Daylight, below ceiling of 3,000 feet, knows the ocean is there, climbs rolls, falls, climbs rolls past 97 degrees, all this in a volitional manoeuvre. Very ill advised, but. Someone else consider the floor, the RTLU, etc. I think 447 lost her tailfeathers after upset, after final ACARS, at altitude. Machaca's rotogravure gives a slight push. That jig bearing the siren sculpture, I agree, it is not your standard hard point rotisserie.
PBL I briefly mentioned a pilot in command considering a Ditch, but very early, and mostly as a prayer. Who else talks of Ditching? It is a fleeting thought, perhaps, but I think no one on board believed it in the realm.
Roll, no Bug, no Horizon, the nose is down, fix the roll fix the roll now pitch up slowly, slowly Airspeed Airspeed, Pitch up, no down, roll roll. All the way down. Another tragic Airbus, 587, had daylight, the standard issue spunky Rudder, and ended up inverted, rolling slowly. If she had been 100knots faster, at say 35k feet, she could not have even kept her svelte body in one piece. We are likely ignoring 447's THS at the expense of a better view. She kept it on descending in an airstream of perhaps 200 knots that was virtually 90degrees verse aerodynamic? Loaded with fuel, buffeted and changing drag quickly and heavily. With the kind of Pitch angle excursions in the Perpignan crash, the fully loaded tail would no more withstand separation than 587 did her VS/Rudder. It articulates, and has "Rudders" with better loading than the actual Rudder. Changing from 50 degrees up to 19 degrees down, (Perpignan) is virtually 70 degrees of sweep. Protections?
GreatBear To travel to "likely" involves a bonfire of the vanities through the Possible, and even the ridiculous. It is necessary to goad with the impossible those who defend the unkown, those who don't want to know, or stand to write big checks if Pollyanna really is full of crap.
bear
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PBL
Now that you mention "music", the relationship to AF447 may well be that the V/S twanged like a tuning fork on impact with terra oceania.
Bearfoil
The resonance created by such a vibration could easily be responsible for the outer end of the starboard side of "arm 36 g" parting company at the hinge bearing bolt. But don't forget there was also +36g helping. What tests on the clevis joints did Airbus do with regard to harmonic resonance? Not the sort I've implied - that's for sure.
More rhetoric....
mm43
Now that you mention "music", the relationship to AF447 may well be that the V/S twanged like a tuning fork on impact with terra oceania.
Bearfoil
The resonance created by such a vibration could easily be responsible for the outer end of the starboard side of "arm 36 g" parting company at the hinge bearing bolt. But don't forget there was also +36g helping. What tests on the clevis joints did Airbus do with regard to harmonic resonance? Not the sort I've implied - that's for sure.
More rhetoric....
mm43
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HazelNuts39
At this point, the material is irrelevant. The Arm is meant to resist tension in a roughly linear fashion, depending on the angle of the deck at contact. It isn't engineered, nor is anything else, to withstand the loads of Water entry at any velocity. It is a handy element to examine because it is available, and as evidence, can help (perhaps greatly).
We are to accept as virtually certain the VS popped out after injecting itself into the mounting bed, at an angle very similar to tailstrike (~). What happens? the VS destroys the massive and complex architecture of the mass as it enters, and the teensy little tip of Arm36g pops off. I have designed and built hinges and articulating panels for the last 30 years, in many applications, and have written legal prose to describe Failure analysis. The Rudder at the speed necessary to destroy the sub structure would have rippled, torn free of everything, and the hinges would be toast.
Look at the Hinge stack on the Rudder's articulating edge. They are conformal, appear to be ready for a change of airframe and save some carrier the cost of a new one. The hinge's Design condition is torsional, its strength is in the plane of sweep, stop to stop. Like the VS, the failure postulated involves the Hinges in anything but a planned for event. I wouldn't expect them to give up without a fight, but Rudder vertical energy seems to have left them unscathed. I stand to be corrected; I am but an observer privy to some nice photography, The Rudder VS looks like it went to the Waltz, not to a destruction derby.
Tension? nothing beats Titanium. Aluminum? Again, it doesn't matter, the Newtons were there, but I think the VS was in another place at the time.
henra
I am satisfied that my last model gave a respectable report on a falling structure. I have a design, and a digital set to build a 1/4 scale model. Maybe if some one wants one, we'll take a balloon ride over the ADIZ. I know a Coastie.
mm43
I postulated a serious symphony due to Rudder Flutter at altitude, the vibration plus the impossibly rapid reversing of torsional loading may have done in our little tip. Again, the Hinges, Boss.
bear
At this point, the material is irrelevant. The Arm is meant to resist tension in a roughly linear fashion, depending on the angle of the deck at contact. It isn't engineered, nor is anything else, to withstand the loads of Water entry at any velocity. It is a handy element to examine because it is available, and as evidence, can help (perhaps greatly).
We are to accept as virtually certain the VS popped out after injecting itself into the mounting bed, at an angle very similar to tailstrike (~). What happens? the VS destroys the massive and complex architecture of the mass as it enters, and the teensy little tip of Arm36g pops off. I have designed and built hinges and articulating panels for the last 30 years, in many applications, and have written legal prose to describe Failure analysis. The Rudder at the speed necessary to destroy the sub structure would have rippled, torn free of everything, and the hinges would be toast.
Look at the Hinge stack on the Rudder's articulating edge. They are conformal, appear to be ready for a change of airframe and save some carrier the cost of a new one. The hinge's Design condition is torsional, its strength is in the plane of sweep, stop to stop. Like the VS, the failure postulated involves the Hinges in anything but a planned for event. I wouldn't expect them to give up without a fight, but Rudder vertical energy seems to have left them unscathed. I stand to be corrected; I am but an observer privy to some nice photography, The Rudder VS looks like it went to the Waltz, not to a destruction derby.
Tension? nothing beats Titanium. Aluminum? Again, it doesn't matter, the Newtons were there, but I think the VS was in another place at the time.
henra
I am satisfied that my last model gave a respectable report on a falling structure. I have a design, and a digital set to build a 1/4 scale model. Maybe if some one wants one, we'll take a balloon ride over the ADIZ. I know a Coastie.
mm43
I postulated a serious symphony due to Rudder Flutter at altitude, the vibration plus the impossibly rapid reversing of torsional loading may have done in our little tip. Again, the Hinges, Boss.
bear
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Originally Posted by bearfoil
... and the teensy little tip of Arm36g pops off.(...) The Rudder at the speed necessary to destroy the sub structure would have rippled, torn free of everything, and the hinges would be toast.
Look at the Hinge stack on the Rudder's articulating edge. They are conformal, appear to be ready for a change of airframe
Look at the Hinge stack on the Rudder's articulating edge. They are conformal, appear to be ready for a change of airframe
On the other hand, if you suspect large aerodynamic loads on the rudder, due to control inputs, sideslip angle or flutter, wouldn't those have damaged at least some of the 'hinge arms'?
regards,
HN39
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GB, mm43, bearfoil,
thanks for the moderate, friendly and thoughtful replies to my plea. I wasn't really grumping about the dialectics of the discussion - I support that style otherwise I wouldn't be around here and reading - but was expressing frustration more that the style seems sometimes to take priority over quality. For example, here a private comment from an engineer colleague:
When some interesting thought is expressed, I find I often have to work hard at it to get it into some sort of reasonable shape before I can absorb it, and I was opining that a bit more attention could be paid to dotting the t's and crossing the i's at the first writing. But it is your discussion, so feel free to ignore!
As for A=443, fascinating information Finn47 and GB! I had no idea, but it does account for why I can't play along to the Mahler on my tin whistle. I am not sure I go along with this tone inflation - real musicians play A416 and it would say so on my bumper sticker if I had a car.
PBL
thanks for the moderate, friendly and thoughtful replies to my plea. I wasn't really grumping about the dialectics of the discussion - I support that style otherwise I wouldn't be around here and reading - but was expressing frustration more that the style seems sometimes to take priority over quality. For example, here a private comment from an engineer colleague:
Originally Posted by anonymous comment
I am not encouraged ..... when I read of "Volumetric Area" in m^3 or "Force" given the dimensions of m.kg/sec (this is equally treated as a statement of energy where it actually has the dimensions of momentum)
As for A=443, fascinating information Finn47 and GB! I had no idea, but it does account for why I can't play along to the Mahler on my tin whistle. I am not sure I go along with this tone inflation - real musicians play A416 and it would say so on my bumper sticker if I had a car.
PBL