It looks like you're using an Ad Blocker.

Please white-list or disable AboveTopSecret.com in your ad-blocking tool.

Thank you.

 

Some features of ATS will be disabled while you continue to use an ad-blocker.

 

New FDR Decode

page: 16
12
<< 13  14  15    17  18  19 >>

log in

join
share:

posted on Nov, 9 2009 @ 12:08 PM
link   
reply to post by turbofan
 


Here is a perfect example of what's wrong with truthers generally and PFT specifically.

Your misleading contention that a pressure altimeter is required to be accurate to +- 20' in an aircraft has been soundly and conclusively refuted. Even you now agree that +- 75' is the FAA tolerance specification and your messiah corrected you several pages ago. Yet you continue to pretend that you were correct all along and attempt to get the discussion bogged down in irrelevant trivia.

I won't swallow the bait. You can continue to try to divert attention from the FACT THAT YOU WERE WRONG as long as you want.

Have a good day, Turbo, I have better things to do than tolerate your nonsense.

Ta ta

[edit on 9-11-2009 by Reheat]




posted on Nov, 9 2009 @ 12:27 PM
link   

Originally posted by Reheat
You can continue to try to divert attention from the FACT THAT YOU WERE WRONG as long as you want.


They do that quite a lot, actually. The latest, in addition to not really knowing what is going with the Baro/Pressure altimeter in the high speed/low altitude environment, is that *now* we have the aircraft performing wonderfully in that self-same environment when the PfT latest film has the wings ripping off.

They really don't know what they want to talk about. I can't wait till The Trials come and we can really hear from them.



posted on Nov, 9 2009 @ 01:10 PM
link   
Add this to the list of deceptions regarding AA 77, the flight path and the FDR analysis. This essay is in essence what many of us have said all along. Now it's confirmed with shown work by a North Eastern University Professor of mathematics who is also an MIT graduate in mathematics.

The trash math being addressed originated from the fake R_Mackey registered here who proclaims himself a co-founder of PFT. It's also on video.

For the few who will understand........

www.ccs.neu.edu...

[edit on 9-11-2009 by Reheat]



posted on Nov, 9 2009 @ 02:52 PM
link   
reply to post by Reheat
 


Translation of the quoted reply:

Reheat has ZERO knowledge of the Boeing 757-200 PA static system routing.

Reheat has ZERO knowledge of how to interpret the FAA spec. vs. a manufacturer spec.

Reheat has ZERO interest in learning how the system really works.

>>>>>>

It would take Reheat only seconds to list off the devices connected to the
PA system if he knew sincerely.

It would take Reheat only seconds to understand the bench test tolerances,
and function of accuracy of altimeters as altitude changes...if he understood the
bench test procedure.

This is a PRIME example of GL's who would rather HIDE behind their screen
name than learn the "science".

We'll see if Tom can save face.



posted on Nov, 9 2009 @ 02:57 PM
link   

Originally posted by ReheatFor the few who will understand........

www.ccs.neu.edu...


That link is garbage and the "NON FDR" minded individual believes that
the file ended 6 seconds before impact with a speed of 462 knots and
a DME value of 1.5 nm!


Only Reheat could propagate such nonsense. Furthermore, the latest
seconds decoded by Warren Stutt highlight how worthless the CCS.NEU.EDU
link really is.

So, which one are you going to stick with Reheat? You can't believe
both...they contradict each other!



posted on Nov, 9 2009 @ 03:00 PM
link   

Originally posted by trebor451 The latest, in addition to not really knowing what is going with the Baro/Pressure altimeter in the high speed/low altitude environment, is that *now* we have the aircraft performing wonderfully in that self-same environment when the PfT latest film has the wings ripping off.



Care to explain how flight 93's pressure altimeter worked fine at a
faster descent rate?

Which data are you going to throw away?



posted on Nov, 9 2009 @ 03:07 PM
link   

Originally posted by trebor451

Errr....I thought the wings would rip off at these speeds. At least that is what you said over at your club house web page.

Now we find out that at 530 mph is "well within the envelope of the aircraft with respect to compressibility issues", which would no doubt impact aircraft structural considerations.

What is it? Will the wings rip off or will the not?

By the way, could you get Kolstad or Lankford to post something about SAMs at the Pentagon, please? I'm still curious why you would support an affidavit that is so far off the reservation with regards to...*cough*...Truth.

And it can't be restated enough that all of this data comes from the FDR found in the rubble of the Pentagon. Which, according to the pilots for Truth, proves that AA77 flew over the Pentagon!

Reheat and tom have made very convincing arguments in this thread, and all Turbofan and R_Mackey can do is desperately try to draw attention away from that, and continually change the subject. It's obvious who the pretenders are in this thread.

Even a lay person such as myself can understand that the accuracy of a system cannot be greater than the sum of the errors of each part of that system. Turbofan and R_Mackey don't seem to understand this.



posted on Nov, 9 2009 @ 08:45 PM
link   
If it's not obvious enough, someone has used my name and posted a bunch of nonsense. Disregard any future use of the account "T_Desideri"
on any forum. I only post under "Turbofan".



posted on Nov, 9 2009 @ 08:54 PM
link   

Originally posted by turbofan

Originally posted by ReheatFor the few who will understand........

www.ccs.neu.edu...


That link is garbage and the "NON FDR" minded individual believes that
the file ended 6 seconds before impact with a speed of 462 knots and
a DME value of 1.5 nm!


Only Reheat could propagate such nonsense. Furthermore, the latest
seconds decoded by Warren Stutt highlight how worthless the CCS.NEU.EDU
link really is.


Nonsense, turbofan. Warren Stutt's new decode (the subject of this thread)
confirms that several seconds were missing from the data used
by Rob Balsamo, proving that Balsamo's contrary claims (in the video and
elsewhere) are incorrect.

When I get time, I will create a new page that summarizes what we have learned
from the new data Warren has extracted, and add a link to that new page from
the existing pages.

My web page is relevant to this thread for another reason: To demonstrate that
Rob Balsamo is willing to admit his errors when he is wrong, the person posing
as R_Mackey claimed that Rob Balsamo had admitted his 11.2g calculation was
wrong, pointing to a PfT page that promotes a video "correction". The poseur
conveniently forgot to say that Balsamo's video "correction" promotes an equally
bogus 10.14g. My web page reviews Part 1 of the PfT/CIT video, identifies
several of Balsamo's major errors, and shows that correct calculations would
have yielded a result of less than 2g.

Part 1 of the PfT/CIT video, narrated by Balsamo, amounts to an argument from
authority. Some people just don't have enough technical background to avoid
being taken in by Balsamo's bluster. That's why I posted my review as a web
page, and mentioned my own credentials within the review.

BTW: Although all of my academic degrees are in mathematics, and my PhD
was obtained through the pure mathematics program at MIT, I make my living
as a computer scientist.

Will



posted on Nov, 9 2009 @ 10:09 PM
link   

Originally posted by cesura
BTW: Although all of my academic degrees are in mathematics, and my PhD
was obtained through the pure mathematics program at MIT, I make my living
as a computer scientist.

Will


Will,

It appears you have spent a lot of time on Rob Balsamo attempting to debunk his work. Have you ever confronted Capt Bob at their forum or through email? If so, what was the reply? If not, why not?

It appears Capt Bob is causing quite a stir among self-proclaimed "authority" coming out from the wood-work, many who claim to have much more experience than Balsamo, who also claim Balsamo doesn't have a clue. Why spend so much time obsessing over Balsamo?

An old saying comes to mind in which the layman understands, "You only get flak when you are over the target".

Will, being that you admit to having much more experience and credentials in mathematics, from MIT no less, than does Balsamo, you validate Balsamo's arguments when you take the time to write such lengthy papers.

Will, I have briefly skimmed through your obviously time consuming papers you have written on Balsamo. You accuse Balsamo of "technobabble", yet in your attempt to debunk Balsamo, you offer information such as this;



Let f(t) be the position of the aircraft at time t. The aircraft must be sufficiently high at the VDOT antenna or Navy annex, it must collide with the base of the Pentagon at time 0, and its vertical velocity at impact must be 0 (for level flight). In addition, its horizontal velocity at impact is v0 = 781 ft/sec. The equations that f(t) must satisfy are:

* f(t1) = ‹ x1, y1 ›
* f(0) = ‹ 0, 0 ›
* f ′(0) = ‹ v0, 0 ›

To obtain a solution f(t) with constant ground speed and constant vertical deceleration a, we add the equation below. Specifying a zero horizontal acceleration implies a constant horizontal velocity (ground speed), so the time at which the aircraft is at the VDOT antenna or Navy annex is t1 = x1 / v0.

* ∀ t ∈ [ t1, 0 ] f ″(t) = ‹ 0, a ›

The solution to that boundary value problem is

f(t) = ‹ v0 t, 1/2 a t2 ›

where a = 2 y1 / t12. The first derivative of f is the velocity as a function of t, and the second derivative of f is the acceleration as a function of t:

f ′(t) = ‹ v0, a t ›
f ″(t) = ‹ 0, a ›



I suppose the average layman will understand your equations over what Balsamo has presented?

Again I ask, have you confronted Balsamo directly with the above? You sure do spend quite a bit of time on him.

Let's face it folks, all of this is "techonbabble" from both sides of the debate for the average layman, and as such, an argument from authority from each side. One has to ask, who has the growing list of verified peers supporting such work? Who offers many tools and aids for the layman to digest the information? (source links, visual presentations... etc)

Here is a hint:

pilotsfor911truth.org...



posted on Nov, 9 2009 @ 10:32 PM
link   

Originally posted by R_Mackey
One has to ask, who has the growing list of verified peers supporting such work?


Ok. I'll ask. Who has a growing list of people who believe the Pentagon had surface to air missiles that were "stood down" on 9/11?

Who has a growing list of people who don't understand what the Camp Springs 1 departure is and does?

Who has a growing list of people who believe a Air National Guard C-130 was vectored to fly along the very edge of Prohibited Area 56 when all radar and voice recordings indicate it was where it should have been - on the Camp Springs 1 departure?

Who has a growing list of people who believe the wings of a Boeing 767 will rip off at 450 knots? Unless they need to stay on to bolster a claim that the aforementioned speed is "Well within the envelope of the aircraft with respect to compressibility issues..." - in which case they won't.

Who?



posted on Nov, 9 2009 @ 10:34 PM
link   
The poseur posting as "R_Mackey" has directed my attention
to several points concerning my review of Rob Balsamo's
farrago of technical errors:
www.ccs.neu.edu...


Originally posted by R_Mackey
Will, being that you admit to having much more experience and credentials in mathematics, from MIT no less, than does Balsamo, you validate Balsamo's arguments when you take the time to write such lengthy papers.

Many competent professionals agree that recognizing Rob
Balsamo's existence gives him more recognition than he
deserves. On the other hand, there may be a few honest
people who are merely taken in by his arguments.


Originally posted by R_Mackey
I suppose the average layman will understand your equations over what Balsamo has presented?

Millions of laymen have taken calculus or a basic course in
physics, which means they can understand my equations. For
others who have not, my review serves to notify them that
competent professionals regard Balsamo's arguments with
disdain.


Originally posted by R_Mackey
Again I ask, have you confronted Balsamo directly with the above?

My review links to a web page that tells the story of my
previous interaction with Balsamo. If you take the time
to read that history, you should understand why a direct
confrontation with Balsamo would be a waste of time, and
(as you argued above) might well give him more publicity
than he deserves.

Rob Balsamo, like you, is quite a poseur.

Will



posted on Nov, 9 2009 @ 10:58 PM
link   

Originally posted by cesura
The poseur posting as "R_Mackey"


And I am a poseur how? Certainly you have proof of this? Perhaps some calculus equation?

Is there another "R_Mackey" registered here at ATS or another ATS member with the real name R_Mackey? If so, I will certainly ask the mods to change my screename.

(By the way, Is it a violation of ATS T&C to impersonate another already registered ATS member? If so, the mods may want to look into Turbofan's concerns before perhaps a lawsuit is served. Just my opinion of course)

From what I understand, Ryan Mackey is not registered here under any name, nor have I ever claimed to be Ryan Mackey from JREF.



Many competent professionals agree...


Source? Names?

So far, the only competent professionals who agree and can be verified are listed here.

pilotsfor911truth.org...

The list grows.

Do you feel they are incompetent? If so, have you reported it to the FAA and their respective employers? If not, why not? Are you not concerned with Flight Safety? Some are based right out of Boston.




Millions of laymen have taken calculus or a basic course in
physics, which means they can understand my equations.


You accused Balsamo of technobabble. You used technobabble yourself in a poor attempt to debunk his work without even confronting Balsamo. Millions of layman have taken student pilot courses. Your point is a logical fallacy.

You claim to be an instructor, are you familiar with the Fundamentals of Instruction? If so, are you familiar with aids to enhance learning? Do you know the definition of learning?



Originally posted by R_Mackey
Again I ask, have you confronted Balsamo directly with the above?

My review links to a web page that tells the story of my
previous interaction with Balsamo.


So your answer is no, you haven't confronted Balsamo directly with the information you have obviously spent quite a bit of time putting together. Thank you for answering.



posted on Nov, 9 2009 @ 11:35 PM
link   

Although all of my academic degrees are in mathematics, and my PhD
was obtained through the pure mathematics program at MIT, I make my living
as a computer scientist.


If you're a math major, then figure out the error in your assumption:

1.5 DME +/- 1 nm from the airport beacon intersecting the damage path
with an aircraft moving at 462 knots is how many seconds to "impact"?

If you believe your assumptions (IE: errors) on your page, then
you cannot agree with Warren's data; specifically SIX SECONDS OF
MISSING DATA.

Still waiting for any of those Boeing 757-200 experts to tell me what
devices are connected to the PA static port:




What the heck is taking all of these "experts" so long to respond? Surely
the must have some documentation to state that several instruments
accessing the port are causing errors in PA reading!



[edit on 9-11-2009 by turbofan]



posted on Nov, 10 2009 @ 07:48 AM
link   

Originally posted by R_Mackey

You accused Balsamo of technobabble. You used technobabble yourself in a poor attempt to debunk his work without even confronting Balsamo. Millions of layman have taken student pilot courses. Your point is a logical fallacy.


You're welcome to demonstrate that Balsamo's claims are not "technobabble." See the top frame of my avatar from Balsamo's animation? It represents the cockpit view the pilots had from the jet as it started it's supposed climb "over and away from the Pentagon." The other two pictures represent what Balsamo's "flyover" would have looked like from the position of the parking lot security camera.

Do you understand that, R_Mackey? Do you understand that we don't have to debunk his claim? Do you understand that Balsamo has yet to provide any positive evidence that any "jet flew over and away from the Pentagon" as he claims?"

Surely you can provide positive evidence for Balsamo's claim, can you not, R_Mackey?



posted on Nov, 10 2009 @ 07:58 AM
link   

Originally posted by R_Mackey
And I am a poseur how? Certainly you have proof of this? Perhaps some calculus equation?

Just the evidence of your posts in this thread. Most
importantly, you have pretended to technical knowledge
you do not possess, and resorted to a variety of red
herrings and other evasions when your mistakes were
exposed.


Originally posted by R_Mackey
From what I understand, Ryan Mackey is not registered here under any name, nor have I ever claimed to be Ryan Mackey from JREF.

Your posts also reveal you had known of Ryan Mackey's
relevance to 9/11 studies before you selected the
screen name behind which you are hiding. You must
have known your pseudonym would be misleading, but
you used it anyway. In that sense, too, you are a
poseur. Your disingenuity above just confirms that.


Originally posted by R_Mackey
Do you feel they are incompetent? If so, have you reported it to the FAA and their respective employers? If not, why not? Are you not concerned with Flight Safety? Some are based right out of Boston.

Competence as a professional pilot does not imply
competence in engineering, physics, calculus, electronics,
digital recording, computer software, or any of the myriad
other subjects on which Rob Balsamo has pretended his
acolytes were authoritative.

I'm sure most core members of Pilots for 9/11 Truth are
competent as pilots. (I can't say that for all of them,
because some have stated for the record that they would
not have been able to fly an airliner into the Pentagon
or a WTC tower.) Few pilots are competent mathematicians
or physicists, however, and those are the professionals
whose competence is relevant to Part 1 of the PfT/CIT
video I reviewed.


Originally posted by R_Mackey
You accused Balsamo of technobabble. You used technobabble yourself in a poor attempt to debunk his work without even confronting Balsamo.

Apparently you are unable to distinguish rigorously
correct mathematics/physics from technobabble.

Perhaps you have not viewed the PfT/CIT video that was the
subject of my review. Had you done so, you'd have known
that Balsamo acknowledged that his critics had informed
him that the correct result was about 1.62g, not 11.2g.
Instead of seeking competent help, Balsamo just dismissed
his critics' calculations with ridicule and technobabble.

Informing Balsamo of his errors would have been redundant;
he already knew of them. Like you, he would have dismissed
my calculations as foolishly as he dismissed those of the
real Ryan Mackey.

Will



posted on Nov, 10 2009 @ 11:34 AM
link   
Response From the REAL Ryan Mackey

Well, looks like my impostor has finally realized that strange taste in his mouth was his own foot. Let me therefore explain, again, for those who are interested, the actual significance of the Critical Mach Number and its relevance to civil transport.

You may recall this all started a couple of pages ago, when I tried to explain how the onset of compressibility in flight does not mean the same thing as "compression," which is one of many idiotic things said by Cap'n Robby Rob. In transonic flow, pressure can go up, and it can go down. This can mean a static probe reads artificially high or low depending on exactly what's going on with the flow. As evidence, I submitted the well-known Prandtl-Glauert Singularity, which is responsible for vapor cone formation at high subsonic speeds, and is evidence of lower than ambient pressure.

The Prandtl-Glauert Singularity arises at the Critical Mach Number. This number has a very specific physical meaning. It is the precise "speed," or Mach number, at which at some point on an airfoil, the air flowing over it is accelerated to exactly Mach 1. Thus, below the Critical Mach Number, there are no shockwaves anywhere. At or any speed above the Critical Mach Number, there will be shocks present. This marks a qualitative change in the flow behavior, hence it is a "Critical Number."

I also remarked in passing that Boeing passenger jetliners frequently cruise at or above the Critical Mach Number. I did not make a mistake. I also, incidentally, did not get that information from Wikipedia, as was alleged on AboveTopSecret by the impostor -- I learned this in my graduate studies, and confirmed it years later working with Boeing. However, it is good to see that Wikipedia has it right. It's not always or even usually wrong, just be sure to check for accuracy if it matters.

This little fact wasn't central to the discussion, so I was surprised to see Cap'n Bob jump on it. But in typical Truther fashion, he indulged in a bit of ad Hominem behavior, specifically the type known as Red Herring -- when shown to be incorrect about the possible effects of compressibility, rather than acknowledge the correct answer or improve his argument, he instead chose to raise a fuss about a nearly irrelevant subject. The reasoning, such as it is, goes like this: If he can convince the readers that I'm wrong about the cruise characteristics of Boeing aircraft, then he can convince you that everything else I say is wrong, and therefore his crackpot theories about September 11th will have a chance. This is completely stupid, of course -- the correct approach would be to find out whether the fact was true, perhaps by contacting Boeing, or if necessary enlisting the services of a transonic wind tunnel. What's at issue here is a simple, isolated fact, no more.

He also could have saved himself additional embarrassment. As noted above, he's confusing Critical Mach Number with other numbers. For example:

Originally Posted by Cap'n Bob
I still see he hasn't learned the definition of supercritical either and that .70 - .72 Mach is no where near Mcrit for a 757, therefore, "compressibility" is not a problem for the 757 at such Mach speed, after all Mmo is .86 on the 757.
Source

This is word salad. Mmo is not the Critical Mach Number. It stands for "Mach, maximum operating" and, depending on the plane, it could be above or below the Critical Mach Number. In the case of the Boeing 757, it is above. (I also note, with amusement, that this Wikipedia page vaguely confuses the two terms, so perhaps it is Cap'n Bob who learned all he knows from that source.)

Mmo is the maximum Mach number at which the aircraft is certified safe to fly. A particularly flimsy aircraft could be limited to well below the Critical Mach Number, although in such a case they probably wouldn't bother to express it. Other aircraft can travel much faster -- an F-15 fighter, for instance, has an Mmo of about 2.5 or so. This is also not limited to military aircraft. The beautiful and tragically retired Concorde, passenger liner, similarly had an Mmo greater than 2.

So what is obvious is that the Critical Mach Number is not, like was thought by the ignorati of pre-1940's, an actual "sound barrier" that cannot be crossed. Whether or not an aircraft can or should be operated beyond this point depends on other effects, like efficiency and safety. So what else can happen?

The appearance of the shock wave at the Critical Mach Number is important in two major respects: First, the shock serves as a disturbance to the airflow, much like placing a tripwire, and this can result in generation of turbulence. Second, the location of the shock can potentially move, maybe even quite a bit, depending on very small changes in the aircraft speed, attitude, and altitude.

The real question is whether the flow behind the shock remains attached, or if it separates from the wing entirely, leaving a region of stagnant air at the wing surface. If the shock is there but the flow remains attached, there's no great change in behavior, only an increase in drag since forming the shock consumes energy. Just because there's a disturbance doesn't mean the flow becomes detached. In fact, many aircraft deliberately create a turbulent boundary layer through little protrusions or wires known as turbulators. This is done because a turbulent boundary layer doesn't grow as quickly as a laminar one, and this can result in reduced overall drag.

As mentioned above, the real question is not the Critical Mach Number, but when the shockwave leads to detached flow. This point is known by a few names, such as the "Drag Divergence Mach Number," and it can be very close to Critical Mach Number, or it can be higher. Sometimes, a lot higher. This depends on wing design.

When the flow is detached, there are a couple of different effects. First, the aircraft wake grows enormously, and this shows up as drag. Lots of drag. Flying beyond this point will burn up lots and lots of fuel. The second is that detached flow leads to a loss of control authority. In the early experiments, diving P-38's and later flying the Bell X-1, this was the real killer, not breakup of the aircraft. In the old P-38's, the flat tail between the booms was in the stagnant region ("stalled") at Mach numbers as low as 0.65 Mach, preventing the pilot from combating the aircraft pitching downward as I'll explain in a moment; this put the aircraft into a dive, it picked up speed, and this frequently led to crashes. The X-1 was a much cleaner aircraft, but it too proved to be nearly uncontrollable as they approached the sound barrier. But these problems were solved. We now build fast aircraft with much larger tails and stronger control surfaces, mounted in cleaner air, enough to counteract these effects.

The other phenomenon, from above, is that the shock location can move quite a bit with minor changes to the flight condition. This can result in the lift force itself "moving" on the wing -- the center of pressure can change radically. When the center of pressure shifts rearward, this causes the aircraft to pitch down, potentially unstabilizing the aircraft. To solve this particular problem, engineers developed swept wings which make the wing appear thinner to the flow and distribute the lift over a broader longitudinal range. Other aircraft play games with fuel redistribution to change center of gravity to match. And, later, they developed supercritical airfoils.

A supercritical airfoil is one whose cross-section is designed to give good performance beyond the Critical Mach Number. Hence the name, "super" == "above" critical. Cap'n Bob seems to think that they increase the Critical Mach Number, and while some of them certainly do, that really isn't what they're for; raising the Drag Divergence Mach Number is what matters. This Dryden whitepaper describes their development, and also the aircraft they benefit. You note that the more radical supercritical wings were not used by any Boeing until the 777 -- the 757 and 767 series use a much more conservative supercritical design.

Most supercritical wings are typified by downward curvature at the lower rear of the wing, and a nearly flat surface on top. The effect on the flow is complicated, but one way to think about it is this: With the flat surface above, the airflow over the top of the wing does not have to change direction at all after it passes through the normal shock. It is therefore more likely to remain attached. Furthermore, the curvature underneath the wing gives rise to what is known as an "aft-loaded" wing, i.e. one where the center of pressure is relatively far back to begin with, and remains far back as speed increases. These are both desirable characteristics if you intend to fly beyond the Critical Mach Number.

Here is the best picture I have found of the 757 airfoil. You will note that it is not terribly bizarre. This is not the kind of wing that will delay shock formation until 0.9 Mach or thereabouts, but it does have aft-loaded behavior.

Boeings, incidentally, have cruised above Critical Mach for a long, long time. For example, the earliest of the modern jetliners is the famous 707, which first flew in 1957 and was derived from the earlier "Dash 80" which dates as far back as 1952. These dates are significant because they are only a few years after Chuck Yeager's fabled flight, and well before research into supercritical airfoils. But surprisingly, the 707 had a cruising speed of 607 MPH, at a service ceiling of 36,000 feet. This speed at that altitude translates to almost 0.92 Mach -- distinctly above the Critical Mach Number.

But how is this possible? We know the problems of controllability are solvable through better control surfaces, which the 707 had. We know we can partly mitigate the effects of compressibility through swept wings, which it also had, even without a supercritical airfoil. But there is still a cost in drag, right? Isn't this flight inefficient, at least?

Well, it's not that bad. You also need to keep in mind that the effect (so called "wave drag") is an induced drag. It only applies to the wings, except for minor other areas where the curvature of fuselage and tail and so on create little shocks of their own. Its magnitude is a function of pitch, and thus lift, rather than a constant cost like the drag off the rest of the plane. So long as the aircraft is only in cruise and not pitched up too steeply, and so long as we don't have detached flow creating a huge wake, the additional drag from compressibility is a fairly minor contributor. We're going really fast so lift also increases, meaning we lower pitch, meaning the wing appears thinner to the flow and reduces the effect. The ordinary drag already scales with the square of velocity, and this won't make it much worse.

There will be a point, of course, where you do get flow separation and drag takes off like a shot, and your aircraft will not be efficient at all, even if it's still safe to fly. But this is not the Critical Mach Number. So long as you're below this other number, the Drag Divergence Mach Number, you can fly just fine, efficiently, safely. And they do.

---

It has been remarked at AboveTopSecret that a pilot wouldn't necessarily need to know these things, any more than your average driver needs to know how a torque converter or recirculating ball steering works. In fact, a pilot really doesn't have to care about the Critical Mach Number. The pilot only needs to know what speeds are recommended and which are safe. Which makes it all the more fascinating that Cap'n Bob appeals so heavily to his "authority" in discussing aerodynamic subjects. He simply has none. As demonstrated by his own comments, he doesn't know this subject and he confuses even very simple terms, like "compressibility" and "compression."

What is more relevant, albeit not surprising, is that his entire club is no better. He claims to have a plethora of knowledgeable pilots backing him up. Well, all it would take is one phone call to Boeing, or any of his gaggle actually taking fluid mechanics courses, and he'd have known that Boeings indeed do cruise above Critical Mach. Or for just one of those pilots to have seen the effect with his or her own eyes, as the picture from WilliamSeger demonstrates. But they didn't do it. The ineptitude is staggering.

Finally, as noted over there, the argument Cap'n Bob put forth is that AA 77 was "well below Mmo," therefore its pressure altimeter could be expected to function. But this is directly at odds with his video, earlier this year, that claims AA 77 could never reach that speed in the first place, and that if it had at that altitude, it would be destroyed. Obviously conditions at that point in flight were either severe or they weren't, they cannot have been both simultaneously.

This kind of confusion is typical in the Truth Movement. If you have no theory and don't care to ever reach a conclusion, you can attempt to claim two completely different things on different days. The goal is to confuse and to include as many alternate viewpoints as possible. This is the exact opposite of science, where noncompetitive hypotheses are discarded, and the solution is as parsimonious as possible.

In closing, it's another banner day for the Truth Movement. This kind of ignorance and obnoxious behavior, to say nothing of the sheer creepiness of pretending to be me while spreading his idiocy, is why Cap'n Bob and his conspiracy theories will never amount to anything.



posted on Nov, 10 2009 @ 11:39 AM
link   
Sorry, I ran out of space......

Sources from my previous post:

Complete Post

Wikipedia Page

turbulators

Dryden Whitepaper

757 Airfoil Picture



posted on Nov, 10 2009 @ 03:23 PM
link   

Originally posted by ImAPepper
Response From the REAL Ryan Mackey

Well, looks like my impostor has finally realized that strange taste in his mouth was his own foot. Let me therefore explain, again, for those who are interested, the actual significance of the Critical Mach Number and its relevance to civil transport.


Well. After that legendary smackdown, I think we can close the book on Cap't Bob and his "growing" list of merry followers and their claims for "expertise" in these areas. We already know they don't understand standard published departures from a military airfield and they believe there were SAM missiles at the Pentagon on 9/11. Why anyone would be surprised that they don't understand aerodynamics, advanced or otherwise, is beyond me. Why, also, anyone would believe *anything* that comes out of that club, from "good morning" to "The sky is blue" is amazing, as well.

On to the next topic.

[edit on 10-11-2009 by trebor451]



posted on Nov, 10 2009 @ 09:39 PM
link   
Wow, for a guy who claimed, "There is nothing to debate", Ryan Mackey sure has a lot to say.

I see it still has not been proven that .70M - .72M is above the critical mach for a 757 and therefore generating compressibility issues which would affect the static system as claimed by Ryan.

Ryan Mackey, the king of posting wall's of text without saying a thing.

Also, you may want to actually read his "Dryden Paper" more closely. Why would "typical cruise" be above a number where drag increases abruptly?


...with this modification, the critical Mach number (Mach number where drag abruptly increases) could be delayed.....


Answer, it isn't. This is why real, verified 757/767 Capts laugh at the statements made by Ryan Mackey.

You may also wish to review his aerospaceweb source which I sourced earlier in this thread, and contradicts the statements made by Ryan Mackey.


These airfoils have critical Mach numbers very close to one (hence the term supercritical) thereby delaying and reducing the large increase in drag due to wave drag. An example of such an airfoil is shown below.


By the way, they are called Vortex Generators, not "turbulators". Do a find for "turbulators" in the Dryden Paper. Then do a find for "Vortex Generators".

I gotta give Ryan one thing, at least he is consistent with sourcing Wiki for his claims. I suppose Ryan will now claim the Dryden Paper, aerospaceweb, Centennial Of Flight sources, American and United 757/767 Captain's who have ten's of thousands of hours, are wrong, but Ryan, who perhaps never stepped into a 757 Cockpit, and Wiki's unsourced claims, are right?

@Will,

Let us know when you confront Balsamo with your claims and his reply. Till then, you're just another self-proclaimed "brain" who makes excuses for the govt story attempting an argument from authority with increased "technobabble" obsessed with Balsamo and his work. You also may want to look at their list of members. Many engineers listed, including an Aeronautical Engineer who helped with the project you say wasn't reviewed by Engineers.

[edit on 10-11-2009 by R_Mackey]




top topics



 
12
<< 13  14  15    17  18  19 >>

log in

join