The general difficulty of the 9/11 flights

[Hitstirrer]

Focus in here has been on a seemingly easy turnaround far from target, course set to target, and than a full throttle dive on visuals. What about two other fairly complex approaches seen on other planes? Still easy for first timers ?

 

[Mick West]

Focus in here has been on a seemingly easy turnaround far from target, course set to target, and than a full throttle dive on visuals. What about two other fairly complex approaches seen on other planes? Still easy for first timers ?

Let's keep on topic please. The question is if they would be uncontrollable at high speed.

New topics in new threads.

 

[Pete Tar]

Focus in here has been on a seemingly easy turnaround far from target, course set to target, and than a full throttle dive on visuals. What about two other fairly complex approaches seen on other planes? Still easy for first timers ?

You'll have to provide the verifications for 'fairly complex manoeuvres' so we can at least agree they actually are.
Do you mean hitting the pentagon and the crash into a field?


Also consider, an inexperienced driver may drive an erratic course because of unfamiliarity with the control inputs that would be hard to reproduce by a professional one - so you could be interpreting simple inexperienced and erratic input as 'complex manoeuvring' (if any such thing can even be shown).

However, they were familiar with the controls, and they did have experience.

 

[Jacob Winters]

I don't think the target would be hard to hit. The pentagon is the largest building in the world. The twin towers were among the tallest at the time and could be seen on a clear day from more than 50 miles away from ground level and probably 100 or more from a jet.

How easy do you think it would be to hit a specific point within the pentagon at such a velocity, and from a very specific approach?

 

[Hitstirrer]

Let's keep on topic please. The question is if they would be uncontrollable at high speed. ;New topics in new threads.

This isn't off topic at all.

Three flights involved high speed; requiring accurate control at sea level. The thread so far has focussed on the simplest. A straight approach and dive. The other two approaches involved high speed manoeuvres to line up to the target. Experienced pilots have failed to duplicate those two approaches in simulators. That would indicate that the planes are indeed not easy to control at the speeds reported in such dense air.

So, on topic, I ask again - Still easy for first timers ?

 

[Rico]

This isn't off topic at all.

Three flights involved high speed; requiring accurate control at sea level. The thread so far has focussed on the simplest. A straight approach and dive. The other two approaches involved high speed manoeuvres to line up to the target. Experienced pilots have failed to duplicate those two approaches in simulators. That would indicate that the planes are indeed not easy to control at the speeds reported in such dense air.

So, on topic, I ask again - Still easy for first timers ?

Beyond what's already discussed here, what specific part of their flight profiles do you find so complex?

Why do you call them "first timers" when they had a commercial pilot in each of the aircraft at NYC?

Specifically how much more accurately do you think they needed to control their aircraft, considering their targets are wider than most runways?

What makes you think the simulators used in the truth trials are anymore accurate at simulating high speed flight than the simulators that did in fact hit their targets?

 

[Hitstirrer]

Beyond what's already discussed here, what specific part of their flight profiles do you find so complex?

The first plane flew down the Hudson two miles to the south of target. When level it made a high speed left turn that was so accurate that no further adjustment to course was required to bring it exactly in line with final approach. That has been likened to you driving a car almost at its max speed a hundred yards to the right of a cone. Then to turn the wheel left to aim to hit that cone without ever adjusting the wheel turn again despite a large amount of understeer at that high speed in such a tight turn. Experienced pilots have strugged to duplicate that.

The pentagon plane declined to dive in as it approached on an ideal course but instead overflew and made a difficult spiralling rapid descent at high speed to arrive exactly on target, a few feet above ground, to fly true and level despite a huge input of ground effect. Experienced pilots have struggled to duplicate that.

Why do you call them "first timers" when they had a commercial pilot in each of the aircraft at NYC?

Errr - because this was the first time they had taken control of large Boeings.

[quote="Rico, post: 86170, member: 839" Specifically how much more accurately do you think they needed to control their aircraft, considering their targets are wider than most runways?[/quote]

All the indications from professional pilots are that its the speed at low altitude that introduces much more problems for inexperienced pilots - which these people were.

[quote="Rico, post: 86170, member: 839" What makes you think the simulators used in the truth trials are anymore accurate at simulating high speed flight than the simulators that did in fact hit their targets?[/quote]

What makes you think that I think that ?

 

[Jeffrey Orling]

How easy do you think it would be to hit a specific point within the pentagon at such a velocity, and from a very specific approach?

I have no idea. Why do you assume the hijackers wanted to hit a specific point or flew a specific flight path approach? That's pure speculation and nonsense.

It makes much more sense that the hijackers simply hoped that they could hit the target at all.. that is get there without being intercepted. I suspect they were thinking that the plane would NOT be shot down as this has never been done before nor was it a stated policy or tactic to foil a hijacking. And they were right... and were able to fly without interference to their targets.

All they wanted to do is hit the pentagon... any part of it.. coming from any direction... even the lawn would do. I don't think they or any non pentagon insiders knows what is where inside the pentagon and what would be the best place to hit it.

Short answer... irrelevant questions.

 

[Hitstirrer]

I have no idea. Why do you assume the hijackers wanted to hit a specific point or flew a specific flight path approach? I don't think they or any non pentagon insiders knows what is where inside the pentagon and what would be the best place to hit it.

I would tend to disagree. Such a detailed and highly researched masterplan would have researched the place in the pentagon where high ranking officials like Rumsfeld would most likely be positioned. There would be many ways of discovering which 'wedge' would make the best target, and which 'wedge' would do little damage to high value officials.

 

[Jeffrey Orling]

I would tend to disagree. Such a detailed and highly researched masterplan would have researched the place in the pentagon where high ranking officials like Rumsfeld would most likely be positioned. There would be many ways of discovering which 'wedge' would make the best target, and which 'wedge' would do little damage to high value officials.

Another assumption... target for what? The only purpose to be gleaned from the hijackings is they wanted to humiliate the Great Satan, demonstrate that he was vulnerable and do it by simply hotting iconic targets. They were not intending to wage anything close to a standard war where they would try to destroy the command and control centers of the enemy. Insurgents understand how to cripple military powers. Bone up on insurgency tactics.

 

[Hitstirrer]

Another assumption... target for what? The only purpose to be gleaned from the hijackings is they wanted to humiliate the Great Satan, demonstrate that he was vulnerable and do it by simply hotting iconic targets. They were not intending to wage anything close to a standard war where they would try to destroy the command and control centers of the enemy. Insurgents understand how to cripple military powers. Bone up on insurgency tactics.

I bow to your greater knowledge of military strategy. Still disagree though.

 

[Jeffrey Orling]

haha. I haven't a clue about military strategy. But I do know that no insurgency or terrorist group has any intention in engaging in anything remotely resembling traditional warfare.

Readers might find this article interesting:

https://en.wikipedia.org/wiki/Fourth_generation_warfare

 

[Hitstirrer]

I haven't a clue about military strategy.

So you don't see an added value to a day of 'shock and awe' in also taking out the Secretary of the Defence and ten Generals ?

 

[Alhazred The Sane]

So you don't see an added value to a day of 'shock and awe' in also taking out the Secretary of the Defence and ten Generals ?

How many Generals did they take out? After all the complex manoevering, etc., to line up with a precise section of the Pentagon, how many top ranking officials were killed?

 

[Hitstirrer]

How many Generals did they take out? After all the complex manoevering, etc., to line up with a precise section of the Pentagon, how many top ranking officials were killed?

Zero. Thats the point. It would have been easier to crash where they were than to avoid them.

 

[Alhazred The Sane]

Zero. Thats the point. It would have been easier to crash where they were than to avoid them.

I take it from that reply that you would have known exactly where all the Generals were located at that precise time then. How many are even in the Pentagon as a matter of course? Are they not scattered about the country on bases? Did Rumsfeld spend much time there? My understanding is that the briefings are held in the White House.

I guess what you're saying is that because no Generals and no Rumsfelds were killed then the pilots were trying not to kill Generals and Rumsfeld, in which case they must not have been terrorists. What were they? Government agents willing to kill themselves for a plot to get what? The US involved in wars? Bush would have found some excuse to go after Hussein anyway, nothing quite so elaborately destructive was necessary for that particular end.

 

[Jeffrey Orling]

So you don't see an added value to a day of 'shock and awe' in also taking out the Secretary of the Defence and ten Generals ?

No measurable difference in what they were trying to achieve.

 

[Hitstirrer]

I guess what you're saying is that...................

Correct. You are guessing.

 

[TWCobra]

The first plane flew down the Hudson two miles to the south of target. When level it made a high speed left turn that was so accurate that no further adjustment to course was required to bring it exactly in line with final approach.

Reference please?

This is the NTSB description and it is nothing like what you claim.

http://www.ntsb.gov/doclib/foia/9_11/Flight_Path_Study_AA11.pdf

 

[Jeffrey Orling]

There is no Hudson River 2 miles south of the WTC.

 

[Jacob Winters]

I don't think the target would be hard to hit.

Am I to presume you are presuming any point of impact would suffice?

The pentagon is the largest building in the world.

With each of the five walls presumably measuring 70917 square feet, yes.

I have no idea.

Thanks. If you have no idea then I must wonder how you can assert you don't think the target would be hard to hit.

Why do you assume the hijackers wanted to hit a specific point or flew a specific flight path approach?

I do not.

That's pure speculation and nonsense. It makes much more sense that the hijackers simply hoped that they could hit the target at all.. that is get there without being intercepted. I suspect they were thinking that the plane would NOT be shot down as this has never been done before nor was it a stated policy or tactic to foil a hijacking. And they were right... and were able to fly without interference to their targets.

[...]

All they wanted to do is hit the pentagon... any part of it.. coming from any direction... even the lawn would do.

Presumption confirmed.

I don't think they or any non pentagon insiders knows what is where inside the pentagon and what would be the best place to hit it.

Short answer... irrelevant questions.

Thanks for your opinions.

 

[Jeffrey Orling]

Am I to presume you are presuming any point of impact would suffice?

With each of the five walls presumably measuring 70917 square feet, yes.

Thanks. If you have no idea then I must wonder how you can assert you don't think the target would be hard to hit.

I do not.

[...]

Presumption confirmed.

Thanks for your opinions.

You're welcome...Whose opinions would you expect from me?
9/11 analyses are drowning in assumptions. Some reasonable others not. But all speculations seems to be built atop assumptions with some facts as well.

Know how to recognize assumptions - good, bad and indifferent.

 

[Hitstirrer]

Reference please?

Yeah- sorry - its been a while since i bothered to look at planes involved. Memory lapse. It was flight 175 that flew parallel to the Hudson way past target rather than a straight on dive like flight 11. It then did a very well controlled descending turn at high speed to arrive dead on with the South tower without any further adjustment needed. See here at mark 1:05 through 1:10 --

 

[Hitstirrer]

There is no Hudson River 2 miles south of the WTC.

Remedial geography class booked.

 

[Mick West]

Yeah- sorry - its been a while since i bothered to look at planes involved. Memory lapse. It was flight 175 that flew parallel to the Hudson way past target rather than a straight on dive like flight 11. It then did a very well controlled descending turn at high speed to arrive dead on with the South tower without any further adjustment needed. See here at mark 1:05 through 1:10 --

Here's what actually happened:

Does the turn through F and G look like "a very well controlled descending turn"? Look at it on the altitude profile. F-G is seven minutes, G to impact is another five.

 

[Hitstirrer]

Does the turn through F and G look like "a very well controlled descending turn"? Look at it on the altitude profile. F-G is seven minutes, G to impact is another five.

The altitude trace doesn't show much. A couple of minutes climb during the first 90 degree turn and one minute levelling off halfway from F to G. The second 90 degree turn appears to be flawless as the rapid diving turn loses height at a constant rate. Then a constant rate of descent to impact. Do you maintain that this ( and the pentagon spiral descent ) would be easy for first timers ?

 

[Landru]

The altitude trace doesn't show much. A couple of minutes climb during the first 90 degree turn and one minute levelling off halfway from F to G. The second 90 degree turn appears to be flawless as the rapid diving turn loses height at a constant rate. Then a constant rate of descent to impact. Do you maintain that this ( and the pentagon spiral descent ) would be easy for first timers ?

Using an autopilot, yes.

 

[Hitstirrer]

Using an autopilot, yes.

Thats the first time its been suggested to me that both flight 175 and 77 pilots were cool enough to programme their autopilot, mid flight, to take over control and allow a smooth spiral turn to impact. Perhaps @TWCobra could advise us if that is a possibility.

 

[Landru]

Thats the first time its been suggested to me that both flight 175 and 77 pilots were cool enough to programme their autopilot, mid flight, to take over control and allow a smooth spiral turn to impact. Perhaps @TWCobra could advise us if that is a possibility.

That sounds good because I'm not an expert.

 

[TWCobra]

The turn wasn't flawless, neither was the final run-in. The radar trace shows numerous small magnetic heading alterations in the final few minutes and then what I term a last second desperate lunge, probably to correct for drift from the northwesterly wind blowing at the time.

That is indicative of a pilot hand flying, but inaccurately. The speed is all over the shop as we say. This rules out an automated guidance system which compensates for drift and controls speed very accurately.

 

[Hitstirrer]

This rules out an automated guidance system which compensates for drift and controls speed very accurately.

My question remains. Do you maintain that this ( and the pentagon spiral descent ) would be easy for first timers ?

 

[Mick West]

My question remains. Do you maintain that this ( and the pentagon spiral descent ) would be easy for first timers ?

That's a rather vague question, as it's super subjective. What qualifies as "easy"? Compared to what?

Based on discussions with other pilots, I'd say everything observed is stuff I could do myself, and I only have solo student certification in a single engine plane. It's just steering and other normal adjustments.

You should take an introductory flying lesson. It's fun and instructive.

 

[Svartbjørn]

What you're forgetting Hit, is that the Pentagon was explicitly designed to withstand unconventional and even nuclear attacks given that it was built at the height of the Cold War. Each layer of the pentagon has several layers within it, as well as several floors beneath the surface. Jeff is right, this was about proving a point that the US was vulnerable and that we could be hurt if someone so chose to do so, not about killing specific targets.

Think of it this way.. imagine the that planes hit the WTC COMPLETELY missed.. what would have happened? They would have smashed headlong into any NUMBER of other buildings in the surrounding area causing the same type of effect. The very point of terrorism, is to cause fear.. two jumbo jets crashing into the middle of the city would DEFINITELY grab attention and cause the same type of effect. Granted, it probably wouldnt have been -as- effective, but the point would have been made, the leaders of the groups responsible would have made the same "yep, we did it ya bastards.. come at me bro" speeches claiming responsibility. The world might be a bit different, or it might be the same, but the point would have been made.. the US is vulnerable to attack.. which is what they were trying to prove. This is why those specific targets were chosen. Its not hard to crash an aircraft on purpose. Point the nose where you want to go and put Sir Issac Newton in the driver's seat.

 

[Redwood]

The Pentagon wasn't built during the Cold War. It was built during WWII. One reason it's made of concrete is that steel is a critical war material - concrete isn't. But you're right; if they had somehow missed the South Tower (hard not to spot with all the smoke coming out of the North Tower, the Empire State Building was just ahead on 34th St.

 

[xenon]

... I suspect they were thinking that the plane would NOT be shot down as this has never been done before nor was it a stated policy or tactic to foil a hijacking.

Actually it has been done before- though not IN the US- but By the US

Iran Air Flight 655 was an Iran Air flight from Tehran, Iran, to Dubai, United Arab Emirates, via Bandar Abbas, Iran. On 3 July 1988, at the end of the Iran–Iraq War, the aircraft serving the flight, an Airbus A300 B2-203, was shot down over the Strait of Hormuz by SM-2MR surface-to-air missiles fired from the United States Navy guided missile cruiser USS Vincennes. The aircraft, which had been flying in Iranian airspace over Iran's territorial waters in the Persian Gulf on its usual flight path, was destroyed. All 290 on board, including 66 children and 16 crew, died.[1] Ranking ninth among the deadliest disasters in aviation history, the incident retains the highest death toll of any aviation incident in the Indian Ocean and the highest death toll of any incident involving an Airbus A300 anywhere in the world
http://en.wikipedia.org/wiki/Iran_Air_Flight_655

It's no surprise that this incident is forgotten as the US media hasn't discussed this act of barbarism since it happened. And even then many were sure it was faked by the Iranians. I specifically remember the "theory" that Iran had loaded up the flight with corpses. It was disgusting.

 

[Jacob Winters]

You're welcome...Whose opinions would you expect from me? 9/11 analyses are drowning in assumptions.

Indeed.

Know how to recognize assumptions - good, bad and indifferent.

Thank you but I am able to recognise assumption, its value, its limitation. I try to refrain from it. I demonstrated yours. My question remained unanswered.

 

[Rico]

My question remains. Do you maintain that this ( and the pentagon spiral descent ) would be easy for first timers ?

A fresh private pilot is taught how to lose altitude pretty early in their training. The reason: in the event of an engine failure, they better be able to know how to land their aircraft in a field without engine power. They can't simply dive a plane to a point because otherwise they'd come down with excessive airspeed and would not be able to safely touch down. There are a number of ways to accomplish the feat. One can do a descending turn in a 360 degree pattern if they can overfly their field high enough. Another method is to do zig zags over a point a mile to a half a mile before the target. Another method is to parallel the target a certain distance, turn perpendicular to it, and then turn to a reverse course (similar to a traffic pattern). There is no set rule on how to do this, but students will realize (or else fail the exercise) if they cannot do a controlled descent while keeping maintaining some orientation of where the target is and keeping the aircraft itself under control.

As far as your question goes, I would say that for anyone with some flying experience, the maneuver makes perfect sense and is easy to do. The flight path of AA77 was a large right hand descending turn well to the south west of the Pentagon. They only had to keep their orientation by noting the landmarks on the ground and/or what heading they were flying to track their target once more after rolling out of the turn. It is but a mere descending turn that goes a full 360. I am confident students with a bit of knowledge can do it. The hijacker of 77 had an FAA commercial pilot license, so I'm pretty sure the maneuver would make sense to him as well. Even if the hijacker had next to nil experience in an airliner, he would only have to know where to find the throttle and the control column to pull this maneuver off.

 

[dbcooper]

they hit the pentagon so directly it chopped light poles on its way in.

 

[Balance]

Speaking as a layman, those plots Mick West posted suggested there were a fair amount of stick and throttle adjustments/refinement made from the point the plane was assumed to be hijacked. The graphs TWCobra posted show this in finer detail. So it suggests to me it was maybe not "easy for first-timers" to hit the buildings but doesn't look particularly difficult and it does seem perfectly plausible they did because of those illustrations, which I believe represent true readings?

 

[Hitstirrer]

. What qualifies as "easy"? Compared to what? You should take an introductory flying lesson. It's fun and instructive.

Easy compared to hard. As in parking a compact car nose into a space with no other cars within ten spaces either side, and parallel parking an SUV in a space a yard longer than the car. Both possible, but a learner can do the first easily, and find the second more difficult.

And I have taken three such lesons as it happens. Two in a light plane and one in a flexwing microlight. At low speed, I would agree that anyone who has a car driving licence would have sufficient co-ordination to perform basic turns under instruction. Once the light touch required is understood it is indeed good fun. The point is that I doubt that I would find a high speed spiral descent even in that light plane as 'easy' as parking a compact nose on.