Boeing spokesperson laughs at the idea of a Boeing 767 going at 500 MPH at 700 feet

I read the thread and had this recurring thought considering the conditions, the maximum theoretical velocity with those conditions (with respect to the points Valhall brought up very clearly (you have my full respect I graduated top of class with a BS in Mechanical Engineering)).

I have questions: can this situation be duplicated by a flight simulator? I am unsure of that because of my ignorance to the sim, but I wonder if the simulator would allow these conditions to occur in a real life scenario. (ie would they be fully accurate?)

Are the models assuming that the plane is not flown wrecklessly?

My recurring thought whilst reading the whole thread: Without procuring a 767, building a mock NYC with the exact air quality, altitude above sea level (air density) etc, and getting someone to throw caution to the wind and actually fly this close to the ground pressing the plane to it's fullest limits, utilizing the same flight path, do we REALLY know what the plane is capable of? I feel that the models of what the plane can do would blow up citing the extreme circumstances.

I may be way out of the box on this, but the idea popped in my head and I felt like sharing it. Everyone may pick it apart at their leisure and I welcome the discussion. Have a good day (or evening whatever the case may be!) ha!

-hooptie

reply to post by hooptie


hooptie,

I can answer you question about the simulator.

I have many hours in a sim...they are designed to be as accurate as they can be. Yes, it is a computer...in fact, each sim has a bank of computers to operate it. A Full-motion sim also requires an entire system of computors just to operate the hydraulics!!

I remember when my airline first bought the B777 procedures trainer. This, I will call it the PT from now on, is a device that replicates the cockpit of the airplane is is designed to mimic. The PT has all of the 'bells and whistles'...meaning that, it will respond as a real airplane, with auto throttles, auto pilot (if engaged). The FMS will respond as if a real airplane, and all of the systems will interact just like the real thing...except!! A PT is a device that does not move. Yet, there is a whole room full of computers to control it.

Jumping from a PT to a Full-Motion Simulator...this is the one you see from outside...on the hydraulic jacks. Sometimes called a 'Full-Flight' simulator, or a 'Six-axis' sim...

When we 'board' this Sim, it is down. When we get in, and the ramp is retracted, the Instructor powers it up...and then the 'fun' begins.

I used the term 'fun' slightly tongue-in-cheek. Every session in the Full-Motion Sim is structured, per the lesson plan.

Let's back up for a bit...here's how it works.

When you train on a new piece of equipment, you first spend about 40 to 50 hours of study...'ground school', we call it. Years ago, it was a tradtional 'classrom' setting, nowadays it is what's called 'CBT'...Computer Based Training. IN any event, it is a syllabus that is approved by the FAA, and each Operator complies with the Federal Regs...

After you pass the 'written' test...used to be called the 'Oral', now it is done on a computer...you progress to the next stages of the syllabus. That would be the PT. (in an earlier post, I described the 'PT'...it means 'procedure trainer')

In the old days, we called this the 'wooden wonder' because, the PT was simply a mock-up of a cockpit, with photographs pasted on to the plywood, and some knobs thrown in to make it 'realistic'.

The mock-up was designed to give you an orientation, at least, to where to find the switches and knobs...

As I pointed out earlier, our PT devices are much more sophisticated,
today. Again, even these devices do not provide motion or visual simulation...

THAT is were we get to the actual simulators. Full Motion, Phase 4 as they are called. So well designed that they will suffice to represent the actual airplane well enough...that the FAA will accept them as sufficient to grant a license...a 'type rating', based only on succesfully flying the sim.

Let me repeat that...the FAA will accept a Simulator, after fully completing the required syllabus, the FAA will grant a type rating to the applicant based on his/her successful Rating Ride in an approved device (FAA speak for a simulator).

Did you all understand that? Before you get all uncomfortable, let me continue...NO ONE is hired to fly at a major airline if he/she is not capable to begin with. What I have described is just a sample of what we go through to transition from one airplane to another.

Back to the type-rating...

Perhaps I should explain pilot certifications...

Here is the progression...Student Pilot, Prvate Pilot ASEL (that means, airplane, single-engine land). AMEL would mean (airplane, multi-engine land). The word 'land' refers to the fact that the pilot does not have a rating that includes floatplanes. I have never flown floatplanes, so I don't know what the term would be...maybe ASELS? Or AMELS?

I have gone too far beyond...once I got my ATP. I have forgotten some of the alphabet soup...and things change, regs change.....

editing to add...I stepped away, lost focus. Back to the airline ops...after all of the ground school, and training, we are not just 'sent out' to fly live flights...we are, next, paired with an instructor pilot...on 'live' flights...for at least 25 hours. That is usually a four-day trip, pretty common in the industry.

The initial 25 hours is called 'Initial Operating Experience'.

After that, as a Captain on a new piece of equipment, you are restricted to 'high minimums' for the next 100 hours...this means, as a Captain on new equipment, you cannot conduct Instrument approaches to normal minima...that is, when a normal ILS is 200/ and 1/2, we have to add 100 feet and 1/2 mile...so, until you get 100 hours on the new equpment, the minima are artifically increased to 300 and 1 mile....

Just FYI....


edit...I reviewed my post, I made some spelling errors...I din not dorect them...you'll figure it out....




[edit on 7-2-2008 by weedwhacker]

[edit on 7-2-2008 by weedwhacker]

Originally posted by weedwhacker

Originally posted by L driver

Originally posted by weedwhacker


Yup! '500 MPH' at 700 feet is unreasonable.

Unreasonable merely to fly at this height/speed, or to maneuver as F175 did (allegedly did)?

Please, L driver, do not 'snip' out of my post to make it look like I said something that I did not!!

If anyone of credible intelligence wishes to read on, they will see that I said 'Yup! "500 MPH at 700 feet is unreasonable.".......BUT, I continued on...402 MPH is not impossible. NOW, I am paraphrasing myself, and I invinte anyone who is reading this discourse to scroll up and see what I actually wrote.

It is disgusting that someone would pull ONE sentence out of another person's post, and take it out of context.

Am I the only one who sees this as wrong??

Weedwhacker, again my apologies. But I still don't see why pulling that sentence out of its context altered its meaning. I try to get the right line between quoting what's relevant without cluttering up posts with too much previoulsy posted material. If I got it wrong in tnis case, them I'm sorry. Please help me understand your point, as I'd like to make sure I'm interpreting you correctly. Are you in fact saying flying at 500mph/700 ft is not plausible, but slowing down the speed to 402 would be plausible? That's how I read what you wrote. Which is why I didn't understand the need to repost the 2nd sentence.


Thank you

reply to post by L driver


L driver,

I thank you for your polite response.

Perhaps I did not make my last post, or posts, clear.

I have read, from others, that the NIST Reports estimated the airplane's speed at about 500MPH.

I simply offered, from my perspective as a pilot, the explanation that maybe 500MPH was an over-stated assumption. It has, though, gotten into the lexicon of the 'de-bunkers', and that is a shame.

Let's take a step back, and understand the difference between MPH and Knots...

A Statute mile is equal to 5,280 feet. A Nautical mile is equal to 6,060 feet. This means, that to convert from Statute to Nautical, we use a factor of 1.15%

In aviation, we use knots...sometimes speeds are translated into MPH, for use in the media, since they, in the USA, are reporting to people who are familiar with MPH....

I know, it gets confusing...especially because most modern cars have KPH on the speedometers!!...

A kilometer is 1000 meters. A meter is just slightly longer that one yard...
BUT, the Metric system has NOTHING to do with the nautical system I am talking about...so please do not confuse the two!

When you see the symbol 'K', it stands for knots. If you see the symbol 'km', that refers to kilometers. This, I think, is where the confusion can begin....

BTW, various spellings of 'meter'...'metre'....that's it.


wanting to add, for L drver, this is not intended as a lesson for you, since I know you know...it is for others who maycome along and read....

OK, carry on!

Originally posted by weedwhacker
I attempt to qualify myself, by posts...you can read many of them...where I can explain things that relate to flying airplanes that wouldn't be known or understood by someone who just uses Google or a PC flight simulator...

Well i do not use Google or PC flight simulator either.

I have a little bit of knowledge about aircraft. I was a crew chief in the Air Force for 4 years.

Have worked in the Defense Special Missile and Aeronuatics Center (DEFSMAC) for the DoD.

And now work for the office of Weapons and Space for the DoD.


[edit on 8-2-2008 by ULTIMA1]

Originally posted by weedwhacker

I have read, from others, that the NIST Reports estimated the airplane's speed at about 500MPH.

I simply offered, from my perspective as a pilot, the explanation that maybe 500MPH was an over-stated assumption. It has, though, gotten into the lexicon of the 'de-bunkers', and that is a shame.

But you seem to continue to ignore that...

1. You haven't been told by others. You've been given a screencap from the actual NIST report and you've been given a link to that report so that you can verify the table is there as it was capped and posted.

2. The over-estimation statement that you keep repeating is the very problem here. No one at this time, in this thread, no matter what side they are arguing, is arguing that the 570 mph (I'm going to get us to use the real number if it cripples me) may be an over-exaggeration. THE PROBLEM IS the NIST used that over-exaggeration in the ONLY model they published, and the ONLY model they could get the intiation of collapse to occur with. (But not until they jacked the fire temperatures up over 100% above their test data.) Since they couldn't get the building to start collapsing (even with the unsupported higher temperatures) when the planes were going at the "less severe" and the baseline damage velocities - AND BECAUSE THEY REFUSE TO PUBLISH THE RESULTS OF THOSE TWO LOWER AIRCRAFT VELOCITY IMPACT MODELS - this leaves that the NIST failure initiation model may be based on an aircraft velocity that was OVER-STATED.

So the question is important from more than a view of "could untrained pilot fly this aircraft this way". It is important because it is a CRITICAL causal parameter in the entire failure model of NIST.

So what I'm trying to point out to you is - getting the REAL answer to this is very important. It is beyond any one of us setting here and going "yeah, I think it could", or "no, I don't think it could". It takes the REAL answer based on the aircrafts specs, L/D curves, etc.


[edit on 2-8-2008 by Valhall]

Originally posted by hooptie

I have questions: can this situation be duplicated by a flight simulator? I am unsure of that because of my ignorance to the sim, but I wonder if the simulator would allow these conditions to occur in a real life scenario. (ie would they be fully accurate?)

Are the models assuming that the plane is not flown wrecklessly?

-hooptie

I can only respond to this with the limited experience and knowledge I have with simulators that were NOT for commercial airliners. So take it for what it is worth.

A simulator is typically designed to expect you to mess up - so it will go to LIMITED extremes. The warnings and reactions it will give will be based around the "design flight envelope". The simulator MAY operate to some pre-set percent exceed beyond the flight envelope before it aborts and basically tells you you lost your craft. But I do not believe the simulators are built to take you all the way to a REAL point of catastrophic failure. And the reason for this is they are trying to get you to fly within an envelope that avoids the REAL point of failure.

Hope that makes sense.

Weedwhacker,

Thank you. Just to make sure I understand correctly, you aren't questioning the ability of a 762 to fly at 500mph at 700ft, just how realistic the assumption is by NIST?

Thanks again

We'd need to determine the actual engine configuration of UA175 as there's about 10% difference in max thrust between the possible types. If the part found in the street is from a CF6 (the one claimed to be from a CFM56) the max thrust is around 52500lb per engine while the suggested JT9D's are lower at 48000lb each.

Is it my lack of enough searching or are aircraft companies a little secretive about drag coefficients?
About all I could come up with was an estimated L/D of 18 at cruise speed & altitude.

570mph (>250m/S) certainly doesn't match the observation (video) of UA175 and would appear to be up to 20% faster than actual which I'd put at closer to 200m/S or 500mph. Why is there no model with reduced building structural integrity which would achieve the desired outcome (eventual collapse) with a lesser impact speed?

Originally posted by weedwhacker
edit to add...no, I DID NOT learn this from the internet, in case you all are wondering. I know this because I actully flew the darned airplnes!!

But does a pilot know the actaul working parts of an aircraft as well as a mechanic?

Most pilots i knew only knew what the instruments told them, they did not know much about the actual working parts.

Oh and for kicks, who knows where the (RAT) Ram Air Turbine was located on an RF-4C.

Upper left aft body. I remember this one because most of the planes I worked on that had them had them placed lower on the fuselage where they could fall down into the slipstream incase they lost power, and this one was in an odd place.

Originally posted by Zaphod58
Upper left aft body.

Well not really aft its about the middle. And yes it comes up instead of down into the airstream.

So, how many hydraulic systems were their and what were they called ?

Now THAT I don't know. I never did any real hands on work with the F-4s. I only know the RAT position because I remember seeing one deployed during an inspection and thought it was really odd that it deployed upwards, anyway, we can continue this in U2U if you want, and stop stealing the thread.

As for simulators, you CAN program some simulators to try to give you an idea of what happens when you go beyond the flight parameters. Boeing has done this to try to recreate several accidents, most notably the Egypt Air accident where the copilot dove them into the ocean. Those are usually the ones at the main Boeing factory or the really high end expensive simulators. The ones used by airlines are generally only programmed to give you flight envelope parameters.

Originally posted by Pilgrum

570mph (>250m/S) certainly doesn't match the observation (video) of UA175 and would appear to be up to 20% faster than actual which I'd put at closer to 200m/S or 500mph.

I agree. If you just take this video

www.youtube.com...

and use the height of the building from the skylobby to the top of WTC 2 (right at 394 ft) as a gage for the distance from the time the plane comes into the frame until impact, the fastest speed I can come up with is 450 mph for the plane hitting WTC 2...and that's trying to force every parameter to produce the fastest possible speed. (i.e. I used 1 second traverse time from the time the plane enters the frame until impact and I believe it's actually over 1 second, and I took the distance from the edge of the frame to the building as right at 660 ft, which I believe is a bit long).

Now, to your question...

Originally posted by Pilgrum
Why is there no model with reduced building structural integrity which would achieve the desired outcome (eventual collapse) with a lesser impact speed?

I'm not sure I understand what you are asking (please clarify)...but, simply put, the lower impact velocities just didn't cause enough building damage combined with fire damage to cause initiation of collapse within the time frame required. The model had to cause collapse initiation in the time between impact and actual collapse of the building and they couldn't get it to do it with the lower velocities. Does that answer your question, or did you mean something else?

Originally posted by Zaphod58
we can continue this in U2U if you want, and stop stealing the thread.

As for simulators, you CAN program some simulators to try to give you an idea of what happens when you go beyond the flight parameters. Boeing has done this to try to recreate several accidents, most notably the Egypt Air accident where the copilot dove them into the ocean.

I did not steal the thread.

Has anyone tried a program for Flight 93 in the sim ?

reply to post by Valhall
What I meant was NIST appears to have treated the energy of impact and fires as the variables with the strength of the towers as a constant. If the buildings were weaker than assumed the collapse could be achieved with a lower speed impact and cooler fires.

It appears they took the first model that worked and presented it as gospel with the now-obvious problems included.

reply to post by Pilgrum


Actually, if you'll look carefully at these two tables for the WTC 1 and WTC 2 and review the plane velocity for each of the three scenarios and the aircraft parameters for each of the three scenarios and the tower parameters for each of the three scenarios, you will see that NIST's sins are greater than what you just stated. The more severe scenarios are a combination of:

1. The greatest plane velocity.
2. The highest aircraft weight.
3. The largest amount of aicraft failure strain (i.e. makes plane stay "together" longer)
4. The lowest tower failure strain (i.e. makes the tower "come apart" faster).




And me not being a civil engineer, I can't speak to exactly what the accurate definition of "live load weight" is - BUT, if live load weight was decreased to the lowest of a possible set of numbers it should "decompress" the structure. And if the structure is in less axial compression, I believe it would be weaker. So I think every single parameter in that scenario is put to the extreme to make the building fail.

Now - you add in the excessive temperatures more than double what they have data to back - and you finally get the towers to fail.

[edit on 2-9-2008 by Valhall]

reply to post by Valhall
Considering the actual plane speed appears to be even less than the lowest they used, the tower parameters would have to be much much lower to compensate. Is a structural issue with the towers getting swept under the rug here?

I keep coming back to all the pics of core columns where the welds failed cleanly with no bending of the columns themselves. NIST seems to have gone for core columns being severed but perhaps they snapped apart like carrots at the welded joints instead. IE the planes might have fractured the building's spine making it unstable enough for fires to cause a total failure.

NIST got their information via the White House executive, who got it from Thomas Eagar of MIT. Thomas Eagar was wrong in everything he presented.

Being a federal bureaucratic agency, the head of the department is answerable directly to the White House executive. Whatever the WH executive orders written will be written, regardless of how much illogical sense it makes to anyone else.

NIST personnel's illogical, unscientific report is proof of that foregoing statement. That can be confirmed by any honest ethical scientist qualified to assess the NIST report. They certainly were not allowed the same samples to test in order to validate or reject, as science dictated, the NIST report.

I find it particularly interesting that Mr. Daniel Lewin, the purported ex-Mossad agent and US computer company founder, plus, WH touted "Flight 11 hero", had such close ties with MIT. Which means, he had inside availability of close business relationship with Thomas Eagar, the author of the Bush administration's "official" report.

archives.cnn.com...

Akamai: Co-founder dies in WTC plane crash
September 11, 2001 Posted: 5:09 PM EDT (2109 GMT)

Daniel Lewin

By Daniel Sieberg
CNN Science and Technology

(CNN) -- Daniel Lewin, co-founder and chief technology officer (CTO) at Akamai Technologies Inc., is said by his company to have died Tuesday as a passenger aboard American Airlines Flight 11. The Boeing 767, originally bound for Los Angeles from Boston, crashed into the World Trade Center in New York. Lewin was 31.

At 8:48 a.m. EDT Tuesday, Flight 11 became the first of two airliners to slam into the 110-story structure, opening an apparently coordinated terrorist attack on the United States that shortly would be felt in Washington as an attack was made on the Pentagon.

Lewin's presence on the plane and death were confirmed to CNN by George H. Conrades, chairman and CEO of Akamai, who said, "Danny was a wonderful human being. He will be deeply missed by his many friends at Akamai. Our thoughts and prayers are with Danny's family, friends and colleagues during this time of national tragedy and personal loss."

Felicia Spagnoli, spokesperson for Akamai, said, “Obviously this is a devastating personal loss and we’re all deeply saddened.” Spagnoli said Lewin left the company’s Boston headquarters Tuesday morning and was headed for Los Angeles on business matters.

In July, Lewin was named one of the Top 10 people of the Enterprise Systems Power 100, a list of industry leaders chosen for their effect on the IT (information technology) landscape and for their ability to influence the industry's direction.

MIT beginnings

Lewin founded Akamai in September 1998, with Tom Leighton, the company's chief scientist, and a leading group of Massachusetts Institute of Technology (MIT) researchers and business professionals. The company's base is in Cambridge, Massachusetts, very near Boston.

Akamai produces technology designed to facilitate online content delivery. Such software is meant to help companies reduce the complexity and cost of operating a uniform Web infrastructure. CNN.com uses a number of services offered by Akamai.

I would not be surprised to learn Purdue University (Purdue Homeland Security Institute) received their information for bogus simulations via Mr. Lewin's company.

Does anyone recognize the name Nathan Lewin? If not Nathan Lewin became notorious as the top defense lawyer for Mossad agents operating in the US. Mossad agents, based in the US, do business as AIPAC and JDL. AIPAC has very close business ties with the Pentagon and DOD.

Originally posted by Pilgrum
reply to post by Valhall
Considering the actual plane speed appears to be even less than the lowest they used, the tower parameters would have to be much much lower to compensate. Is a structural issue with the towers getting swept under the rug here?

Well, the towers being more unstable than the NIST model states can be one answer, or something else happening in the building that weakened the towers could be another answer. At this point arguing between those 2 scenarios would not be the next rational step because what we're at here is the point where the NIST model doesn't account for SOMETHING (pick your poison) and forced the towers to fail based on a model that needed: 1. fire temperatures that can't be supported, and 2. possible aircraft speed that can't be supported. I feel we're still looking at whether 2. is a valid statement or not.