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William Seger

(11,731 posts)
4. With conspiracy hucksters and frauds ...
Thu Jun 26, 2014, 11:53 AM
Jun 2014

... it's sometimes hard to tell where the ignorance ends and the dishonesty begins. It doesn't matter, though, because as I've said, the only way you're going to get out of this one is to gnaw your own paw off. Running away from the smoldering crater of this "epic fail" and telling more lies won't do it. Why do you want to start a new thread to direct people away from this FAA confirmation that FAR 25 means just what it says, and what anyone even remotely familiar with engineering principles would already know:


FAR 25.301(a) says, "Strength requirements are specified in terms of
limit loads (the maximum loads to be expected in service) and ultimate
loads (limit loads multiplied by prescribed factors of safety). Unless
otherwise provided, prescribed loads are limit loads."

FAR 25.303 says, "Unless otherwise specified, a factor of safety of 1.5
must be applied to the prescribed limit load which are considered
external loads on the structure."

FAR 25.305(e) says, "The airplane must be designed to withstand any
vibration and buffeting that might occur in any likely operating
condition up to VD/MD, including stall and probable inadvertent
excursions beyond the boundaries of the buffet onset envelope."

I don't need a great deal of detail, but my question is: For stresses
caused by velocity, is there a margin of safety beyond Vd/Md (i.e. are
those considered to be limit loads or ultimate)?


Subject Re Design Loads
From Gregory.Johnson@faa.gov
To ws@#######.###
Date Today 13:58

Mr. Seger,

This correspondence is in response to your inquiry submitted to the Denver Flight Standards Office relevant to design loads. As you correctly identified in your review of 14CFR part 25, structural design loads are are identified in terms of Ultimate (Ult) and Limit loads.

Limit loads are the maximum load that it is anticipated the structure will see in service. By rule the aircraft structure must be capable of sustaining Limit loads without permanent detrimental deformation. For all loads up to Limit, deformation of the structure must not interfere with the safe operation of the aircraft. Thus consider the limit load as the operational limit.

Design loads are referred to a Ultimate loads which are bound by material properties F = P/A

Ultimate load = Limit load x a factor of safety (1.5) thus Ult. = Limit x 1.5

In design it must be assumed that while the airframe is not intended to experience loads in excess of Limit, a margin or reserve capacity is necessary to preclude structural failure thus the 1.5 factor as the boundary to define Ultimate. As the material capacity is a constant, the design (section area) is the variable to react to the applied loads and preclude structural failure. The loads then that are considered would include such loads flight maneuver, gust, torsion, delta P. From a basic loads stand point an interaction equation would be applied to address these loads. This 1.5 margin then defines the limit within which the aircraft may be assumed to safe operate within the parameters of these type of loading conditions.

An airframe is certified to a maximum velocity that is can sustain in flight and a maximum acceleration to which it can be subjected to and sustain safe flight, maneuver and landing. Each of these criteria are defined in 14CFR under Subpart C. The maximum velocity and acceleration as a design criteria are potentially the most significant considerations of a design for operation within the [font size="+2"]defined Limit load[/font].

I hope this addresses your question

Regards.
Gregory Johnson
Denver Aircraft Certification Office
ANM100D
Phn: (303) 342-1083
E-mail: gregory.johnson@FAA.gov


Thank you, Mr. Johnson; yes, that addresses my question quite well, whether or not Rob Balsamo understands it. And now, we return to the Rob Balsamo Show, already in progress:

> He gets a reply from only one person who states he is an "engine guy and not an airframe guy and cannot comment on aircraft designs."

That's the second time you've deliberately misquoted AlephZero ("I can't comment on specific plane designs" i.e. the 9/11 planes I had mentioned). Since you were already called on it once, this second attempt at distortion is just a lie. But to address the point, an "engine guy" would be a mechanical engineer rather than a structural engineer, but mechanical engineers would need to be just as familiar with the concepts of "limit" and "ultimate" stresses and how to use them in the design process to meet FAA requirements.

> After mind numbing discussions attempting to explain that the "Limit Loads" and "Ultimate Loads" described in FAR Part 25.301 were for... you guess it, Loads, and not speed,...

You're a one-man clown car, Balsamo. To anyone with ordinary reading comprehension, what was "mind numbing" about that thread was your abject inability to grasp the meaning of standard engineering terms, much less the principles, and now you think you can get away with just repeating your own misunderstandings for the umpteenth time. Since you were called numerous times on your deliberate twisting of what I said, right from my first post, this is just a pathetic attempt to hide behind your own ignorance. Anyone with any common sense would recognize that if you add a margin of safety to the stresses -- a.k.a. loads -- approximated for a given speed, then you would have a margin of safety at that speed -- which is the exact purpose, of course. You demonstrate that not only do you not know anything common engineering practice, but you don't even possess that much common sense, and then claim that your own lack of comprehension wins the argument? Too funny even for a ROFL smiley.

> ... and the fact that Seger only first heard of Vd just a short month ago after viewing our film Skygate, ...

Hmm, you seem to have a peculiar notion about the nature of knowledge and understanding. How long ago did you first hear the term Vd, and yet you still don't understand it?

> Seger attempts to find outside help for his creative interpretations, based on his obvious bias.

Yeah, asking for "outside help" from an actual authority is not part of the game you want to play, is it. If you had asked for some "outside help" before making that nonsense video, it would have been considerably shorter. And now, the best you can do to support your "creative interpretation" of standard structural engineering principles is to keep linking to a list that contains more flight attendants than it does aeronautical engineers, and yet ignore that nobody on that list has actually supported it.

> Seger then finally admits that Vd is not a load and is in fact a speed.

It really is as if you think everyone is too stupid to read and understand that thread, so you can get away with another lie. (Or rather, you think the stupid ones will still buy your video?) I corrected your misunderstanding of what I said right from your first misstatement of it, and numerous times since then. So let's say it again: If you add a margin of safety to the loads approximated for a given speed, then you would have a margin of safety at that speed. There's no wiggle room in that for you, Balsamo.

And then you post another Vg diagram. Again, for the clueless, with respect to the issue at hand, that diagram doesn't tell us anything that the Vd number alone doesn't tell us, which Mr. Johnson explains in his response: The Vd conditions of FAR 25.305 are the limit load cases, so they require a factor of safety to get the ultimate loads to feed into the design. If you ignore the requirement to do that, then there is no reason to think that you can meet the requirement that planes must not fall apart at the FAR 25.305 conditions. What the diagram actually says is that the required maneuvering envelope extends to Vd, and the rest of the diagram is completely irrelevant.

But I guess you're right that the game isn't over yet if you just keep posting the same nonsense and lies over and over and over. That's fine with me; I'll just keep posting the same responses and enjoy it for the entertainment value.

Recommendations

0 members have recommended this reply (displayed in chronological order):

William Seger - Epic Fail [View all] johndoeX Jun 2014 OP
Who is Helen Borg Jun 2014 #1
Leslie? delphi72 Jun 2014 #2
Fringe pilot group fails to define Vd, uses googled journalist made up definition superbeachnut Jun 2014 #3
With conspiracy hucksters and frauds ... William Seger Jun 2014 #4
The "Defined Limit Load" johndoeX Jun 2014 #5
Fraud! William Seger Jun 2014 #10
Third time asked Seger, johndoeX Jun 2014 #12
Another feeble attempt at deception William Seger Jun 2014 #14
So, just to be clear... johndoeX Jun 2014 #15
WTF?!?! William Seger Jun 2014 #17
"Flying at Vd puts loads on the airframe" johndoeX Jun 2014 #18
For probably not the last time... William Seger Jun 2014 #20
Ok... now we are getting somewhere.... johndoeX Jun 2014 #21
"Getting somewhere," huh William Seger Jun 2014 #24
Nobody knows? johndoeX Jun 2014 #25
ROFLMAO. There's that bizarre Balsamo "debating" technique again William Seger Jun 2014 #26
The test is based on FAR Part 25 johndoeX Jun 2014 #27
Un-freakin-believable William Seger Jun 2014 #28
Loads johndoeX Jun 2014 #29
ALL types of loads are covered by the definitions in 25.301(a) William Seger Jun 2014 #31
Ding ding ding! johndoeX Jun 2014 #32
"You lose!" shouted Cap'n Bob from the bottom of his smoldering crater William Seger Jun 2014 #33
The FAA johndoeX Jun 2014 #34
Impossible lie exposed, pilots for truth next Gish Gallop superbeachnut Jun 2014 #6
Just a "journalist"? johndoeX Jun 2014 #7
The Vd definition is made up - why fake a definition to support a lie superbeachnut Jun 2014 #8
Why Beachy why? johndoeX Jun 2014 #9
Grade school kids more experience than needed to debunk pilots for truth superbeachnut Jun 2014 #11
"A mathematician"? johndoeX Jun 2014 #13
Flew a desk quote mining lie, mirrors the fake Vd definition quote mining failure superbeachnut Jun 2014 #16
Beachy - where did you get the diagram in your above post? johndoeX Jun 2014 #19
attacking a person, does not make the data wrong - no matter what other topics the person got wrong superbeachnut Jun 2014 #22
So, you agree with Frank? johndoeX Jun 2014 #23
pilots for truth expose they lack the expertise to decode the FDR superbeachnut Jun 2014 #30
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