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

Originally posted by OrionStars



We, the people, are entitled to accept or reject those unproved reports, based on nothing but unproved allegations and opinions.

Fair enough, I suppose. But then, do you also call other plane crashes that involved "incredible" maneuvers unproven events?

Also, what exactly IYO was impossible about the flight parameters on 9/11?

Thanks

reply to post by OrionStars


I'm sorry, Orion, you constantly demonstrate your lack of understanding of anything involving airplanes, you did it again on page two, saying that an airplane will eventually reach a 60 degree angle at some time in its flight!!!

In modern commercial jets, we use a MAXIMUM of 20 degrees Nose Up at any given time. When we practice windshear encounters, that is the recommended pitch attitude, along with max throttle. This is info not relevant to the thread, just background info.

I've noticed you remained incredibly silent after I pointed ut your mistakes regarding EW and GTOW...you don't really seem to understand how airplanes work. Yet, you continue to pretend that you do. That is a shame.

reply to post by L driver


So when plane climbs to reach cruising altitude, at no time does it achieve a diagonal degree angle of 60 with horizontal earth. Is that what you contend?

Originally posted by OrionStars
reply to post by L driver

 

So when plane climbs to reach cruising altitude, at no time does it achieve a diagonal degree angle of 60 with horizontal earth. Is that what you contend?

What the heck are you asking??!!?? No, if you are talking about a pitch attitude, no. You will not see a commercial jetliner in normal operation fly at a pitchof 60 degrees nose up.

Your terminology, there, gives you away as not knowing anything about what you're talking.

Quick lesson...three axes of flight. Longitudinal, latitudinal and vertical.

'pitch' is defined as motion about the lateral axis, relative to the Earth's surface (or horizon, as we call it). 'roll' is movement about the longitudinal axis. 'yaw' is movement about the vertical axis.

The 'four forces'...Thrust, Drag, Lift, Gravity. In simple terms, in a steady-state situation, all four forces are in balance. The only constant in the mix is, of course....gravity!! Add thrust, speed increases, hence lift and drag increase. Drag has many components, if you are a boater you know about one, it's called parasitic drag, and that is simply drag caused by moving an object through a fluid, whether it be air, or water. When lift is produced, another compnent of drag is introduced, and it is called 'induced' drag.

All of this is textbook stuff, need to know but in practice it isn't something you think about all of the time, you just fly the airplane. Like, in a car, you can think about the friction of the tires on the pavement, and how your brakes work with friction, but when you slam on the brakes you don't ponder the physics, you just steer the darn car!

Now I could get into further aerodynamics lessons about 'adverse yaw' effects caused by aileron deflection (this relates more to light airplanes) but that's for lesson 2.

The elevators control 'pitch', about the lateral axis, the ailerons control 'roll' about the longitudinal axis and....drumroll...the rudder controls 'yaw'. In roll, we refer, again to the horizon, as bank angle, in degrees. Pitch, again referenced to the horizon, is called attitude, again in degrees.

Now, every pilot knows about something called 'angle of attack'. This refers to the angle of the wing 'chord' compared to the 'relative wind'...

You see now, you really should take a Ground School course in aviation, because without diagrams and one-on-one instruction it is difficult to teach...

Originally posted by weedwhacker
reply to post by L driver

 

What the heck are you asking??!!?? No, if you are talking about a pitch attitude, no. You will not see a commercial jetliner in normal operation fly at a pitchof 60 degrees nose up.

I did not say planes were ordinarily flying at a 60 degree pitch. I said when climbing and nothing more. At some point, depending on additional weight load over empty and direction the plane is supposed to be going, a plane can indeed eventually reach a diagonal climb to cruise altitude at 60 degrees from horizontal ground. Please note the words eventually and to arrive at cruising altitude.

It all depends on what altitude the pilot decides to cruise when level out occurs. He may decide to level out, bank and turn into correct direction destination, and then climb to final cruise altitude. That climb would most likely be less than 60 degrees relative to horizontal earth.

Originally posted by OrionStars
reply to post by L driver

 

So when plane climbs to reach cruising altitude, at no time does it achieve a diagonal degree angle of 60 with horizontal earth. Is that what you contend?

Orion, please help me understand your question better. I'm not always good at technical questions. I don't know what a "diagonal degree angle of 60 with horizontal" means , or what it has to do with the 9/11 planes. Does it mean climbing at a 60 degree pitch up? That's a term I am familiar with. If so, what exactly are you asking me?

[edit on 7-2-2008 by L driver]

[edit on 7-2-2008 by L driver]

Originally posted by L driver

Orion, please help me understand your question better. I'm not good at technical questions. I don't know what a "diagonal degree" is, or what it has to do with the 9/11 planes.

I need to clarify what you mean. Do you mean you are not familiar with geometry terms?

It has everything to do with the whether or not the 767 is capable of doing a high speed sharp banked angle turn, while not drastically reducing higher speed, particularly close to sea level at 700'. Whoever contends that it can, the onus lies on that person to prove it in real time. Degree of angle is everything in determining possiblility or impossibility, in that particular case.

Originally posted by OrionStars

Originally posted by L driver

Orion, please help me understand your question better. I'm not good at technical questions. I don't know what a "diagonal degree" is, or what it has to do with the 9/11 planes.

I need to clarify what you mean. Do you mean you are not familiar with geometry terms?

It has everything to do with the whether or not the 767 is capable of doing a high speed sharp banked angle turn, while not drastically reducing higher speed, particularly close to sea level at 700'. Whoever contends that it can, the onus lies on that person to prove it in real time. Degree of angle is everything in determining possiblility or impossibility, in that particular case.

OK, got it, I think. Flight 175. Mind if I take this step by step? 1st, are we in agreement that some large airliner/aircraft resembling a 762 hit the South Tower?

Originally posted by OrionStars



I need to clarify what you mean. Do you mean you are not familiar with geometry terms?

I meant I'm not used to hearing a plane banked at 60 degrees described in that wordier way. Now I know exactly what you mean.

Originally posted by L driver

OK, got it, I think. Flight 175. Mind if I take this step by step? 1st, are we in agreement that some large airliner/aircraft resembling a 762 hit the South Tower?

We are not in agreement be it a 762? or 767. Does that make a difference as to whether or not you explain your hypothesis?

Originally posted by OrionStars

Originally posted by L driver

OK, got it, I think. Flight 175. Mind if I take this step by step? 1st, are we in agreement that some large airliner/aircraft resembling a 762 hit the South Tower?

We are not in agreement be it a 762? or 767. Does that make a difference as to whether or not you explain your hypothesis?

Orion!!!

"762" is industry short-hand for a B767-200. As in, a "763" would be a B767-300 and a "764" would be a B767-400.

It is difficult, sometimes, to talk to you, but we try, nonetheless.

BTW, a 60-degree angle of bank IS possible in a B767 or B757, for that matter. In fact, in light airplane training, it is taught as a 'steep turn'. It is a maneuver, in training, designed to familiarize the student with the handling capabilities of the airplane, and to teach the relationship between the varying lift vectors, and how those affect induced drag and airspeed.

In order to be an airline pilot, we also must demonstrate an ability to accomplish a 'steep turn'. This is done in the simulator. We use a 45 degree angle of bank. It is a maneuver designed to test one's ability to pilot within exacting criteria...+/- 100 feet, +/- 5 knots. Roll-out on the desired heading, +/- 10 degrees. This is a training and proficiency exercise, not related to real-world operations, but it does separate the 'men from the boys', as the saying goes.....

I thought to add...in normal airliner operations, with passengers, we will limit our bank angle to 30 degrees. At my airline, we used 25 degrees as standard, as do most companies. In fact, on the B757/767, there is a verbal warning when you exceed 36 degrees of bank...it is a recorded voice that repeats 'bank angle, bank angle'. Naturally, when we do the maneuver in the simulator, the instructor disables that nuisance warning, just for that part of the ride.

I am trying to impart some knowledge here, so I hope it helps....

[edit on 7-2-2008 by weedwhacker]

Originally posted by OrionStars

Originally posted by L driver

OK, got it, I think. Flight 175. Mind if I take this step by step? 1st, are we in agreement that some large airliner/aircraft resembling a 762 hit the South Tower?

We are not in agreement be it a 762? or 767. Does that make a difference as to whether or not you explain your hypothesis?

I'm just trying to find out more about where you are coming from before I proceed. Is your contention that no plane hit the South tower? Or that SOME plane NOT resembling a 767-200 hit the tower?

Thanks

Originally posted by weedwhacker


[ BTW, a 60-degree angle of bank IS possible in a B767 or B757, for that matter.

Thanks. Next time I'm at the airport I'll ask a 767 pilot about 60 degree banks, if I can. Might be hard, as we only get about one or two a day into Boston these days. I've always asked them about flight 77, but never 175. That ought to be fun for a change.

reply to post by L driver


L driver,

Are you ground crew? Tug driver? When you get the Capt on the headset, by all means, ask him if his 767 can bank at 60 degrees...he will say yes. Ask him, also, about 'steep turns' in simulator training, both initial and re-current training...and I bet he will tell you about the 45 degrees...don't lead him on, let him tell you.

BTW, you can ask a 757 pilot also, since the 757 and 767 share a common type rating. In other words, any pilot qualified on one can fly both. Some airlines, per Union rules, separate the two into 'sub-bases' for bidding purposes, meaning, you use your seniority to 'bid' for the airplane, and the geographical base of your choice.

Originally posted by weedwhacker

Orion!!!

What it necessary to address me that way or add any of the unnecessary ad hominem I took out??

BTW, a 60-degree angle of bank IS possible in a B767 or B757, for that matter. In fact, in light airplane training, it is taught as a 'steep turn'. It is a maneuver, in training, designed to familiarize the student with the handling capabilities of the airplane, and to teach the relationship between the varying lift vectors, and how those affect induced drag and airspeed.

Perhaps if people stopped attributing words to me I never wrote, it would be much easier to communicate. I never wrote anything about a "60-degree angle of bank". That is the second time I have stated that.

I know what it means to bank a plane. That is not the type of angle to which I refer. A sharp angle back would not be 60 degrees. It would far less. How many commercial airliners can do what is termed hairpin turn? How many commercial jetliners are able to go into a bank and turn without drastically slowing down before picking up speed coming out of the turn? Any? Or none? Automobiles cannot do it. Why should commercial jetliners, with far more length, weight, and mass to lug around, be any different?

60 degree rotation almost puts the wings vertical to the ground. All it needs is another 30 degrees, and the wings would be vertical to the ground. Are commercial jetliners normally banked at 60 degrees, particularly at near sea level altitudes? Because I have never been in a commercial jetliner when the pilot decided to bank, in order to turn, at 60 degrees. We passengers would definitely know it if that happened. Bank at 35 degree rotation, and the passengers know it. We all start leaning to the inside of the bank.

reply to post by OrionStars


Orionstars,

I will try again, please attempt to stay with me here.

IN a co-ordinated turn, in an airplane, the passengers will not need to 'lean' in any direction. That is not how it works. Lesson 2 in how an airplane flies....

(this would be so much easier with a visual)...Picture a wing, parallel to the horizon, viewed from behind. Imagine an arrow pointing up, this represents 'LIFT'. Imagine another arrow, pointing down, this represents 'GRAVITY'. OK, in steady, unaccelerated flight, these two arrows are the same length, representing a balance of forces. With me so far?

Now, let's put the wing into a left bank. The lift arrow that we discussed earlier is still perpendicular to the wingspan, but because it is now at an angle, it imparts a side force...this is why airplanes turn. BUT, the component that is counter-acting gravity, which is the constant, remember, is now diminished by a slight amount. SO, to increase the size of that 'up' arrow, we have to increase the size of the 'lift' arrow, which is now tilted to the left...how? Well, one way is to change the AOA, that's angle of attack, and that is done with a slight change in the attitude (pitch) using the elevators. But, guess what! Now, we have a slight increase in drag, because of the increased lift generated...and that will result in a slight DECREASE in airspeed. The airspeed variations are negligible in bank angles up to, oh say 30 degrees or so. AFTER that, when the bank gets steeper, airspeed will tend to drop off...so, we add thrust to compensate. THIS is why we teach steep turns in training, and use them in proficiency training. One must ADD power (thrust) in a steep turn to maintain airspeed, while using the elevator to maintain altitude. Conversely, when the turn is complete, and you are rolling out on the heading, you must REDUCE the power to the initial setting, or else you will accelerate above the target speed.

All of the foregoing info relates to flying an airplane skillfully. Brute force, and max throttle, when you are not concerned about engine limitations or being smooth are a differnt thing entirely. THAT is why a hack at the controls could accomplish the terrible events of 9/11.

reply to post by OrionStars


OrionStars,

I will continue with another aspect of your post, regarding a 'hairpin' turn. No, airliners cannot execute a 'hairpin' turn. Not even sure why you mentioned this, I am having trouble following your logic...

If you go out to learn to fly, you will, in the US, get a 'Private Pilot' license. If you wish to further your knowledge, you may wish to get an 'Instrument Rating'. There, you will learn about the 'Standard Rate Turn'. The 'Standard Rate' is also called the '2-minute' turn...what it means is, at that rate, an airplane will complete 360 degrees of turn in 2 minutes. That, of course, works out to 3 degrees of heading change per second. This is what ATC expects of an airplane, when it is operating in an IFR environment, meaning, under IFR rules.

In a light airplane, traveling at about 150 knots, a 30 degree bank will be close to 'Standard Rate'. BTW, when learning to fly on instruments it is important to maintain control, and to not exceed parameters that could lead to vertigo, and subsequent loss of control of the airplane. In fact, vertigo can occur even in level flight, depending on the individual...a sharp turn of the head, for instance...

Rate-of-turn is variable depending on airspeed, at any fixed angle of bank. The controllers know this, and they understand that a B767, for instance, at 250Knots (max speed below 10,000 feet, per FAA regs) will bank at 25 degrees. This WILL NOT result in a 'Standard Rate' turn, of course. As an airliner is vectored in the terminal area, the controller will command speed changes as he 'jockeys' each airplane in his sector, and lines them up for the Final.

A modern jet has minimum safe airspeeds, depending on weight and configuration. A B767, clean, will have a minimum of around 210 to 200 knots in the landing phase. When told to reduce to a speed of, say, 180K, we have to begin to extend slats and flaps. This is just info to, hopefully, educate those who don't fully understand the complexeties of airplanes...

BTW, a B767-200 just after take-off, at near MGTOW, will have a minimum clean airspeed of about 240 to 245 knots. Some heavier commercial jets (the B747 comes to mind...) can have a minimum clean airspeed of MORE THAN 250Knots...in those cases, they are allowed to exceed the 250K max airspeed rule below 10,000 feet.

Well, thanks for reading, hope I've educated someone....

Adding from edit...sheesh!! I should get paid for this! I am giving it out for free...oh, well....

[edit on 7-2-2008 by weedwhacker]

Originally posted by weedwhacker


L driver,

Are you ground crew? Tug driver?

No, just a limo driver. I like to catch air crews as they wait for their hotel vans. Takes the boredom out of standing holding a sign for 45 minutes. Regarding F77, there was one Airtran pilot I spoke with who thinks the maneuvers were absurd, and was clearly an all-around 9/11 skeptic on further questioning. But all the other two dozen or so pilots I have talked to did not think so. I urge anyone who has doubts about the maneuvers question to go to an airport and simply ask pilots what they think of all this. I guarantee one will quickly come to see that PF99T represents the fringe end of commercial pilot opinion.

Originally posted by Zaphod58
Ok, here are some words of professional pilots and engineers for you to take.

Its just too bad there are dozens of other pilots and engineers who say it could not be done.

Also we have a witness who was real close to the Pentagon state that it looked like the pilot was not in control of the plane.

Subject: Hispanic Hero Recalls Experiences
Date: Tue, 30 Sep 2003 12:18:03 -0400
From: Press Service [email protected]
Reply-To: [email protected]
To: [email protected]

By Rudi Williams
American Forces Press Service

"It seemed like the pilot was scrambling to keep control,
and I watched as he dropped lower and lower," Sepulveda
said. "Then he dropped his landing gear and started
coming down even faster and lower.

As it came down, the plane was hitting light poles, the
sergeant said. "Then the right wheel hit a light pole and
the plane popped into a 45-degree angle. The pilot tried
to recover -- go back vertical – but he hit some more
light poles. "

[edit on 7-2-2008 by ULTIMA1]

Orion,

If you'd like, I'd be interested in asking your question to the next 757/67 pilot I run into at Logan. If you want to take me up on this, please give me the exact wording of your question, because I'm not sure of the distinction you are making. If you live near a major airport, maybe you could ask it too. Then we could compare notes.


Cheers
Chris