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Could 9/11 Have Happened In Bad Weather?  
User currently offlineQXRamperMEII From United States of America, joined Aug 2006, 93 posts, RR: 1
Posted (7 years 1 month 4 days 3 hours ago) and read 6891 times:

My girlfriend and I were discussing 9/11 a few days back (she just got done with her recurrent F/A training, and it always comes up), and she asked me a question that got me wondering...could 9/11 have happened the way it did if the weather had been bad?

As I understand it, a few of the hijackers had rudimentary flying skills, enough to keep 757s and 767s flying along. After the takeover, they navigated visually to the targets and ran into them...what if the weather was crap and they couldn't see them? A nasty cloudy, foggy day in New York...even they were able to navigate IFR, it would have been tough to hit the Towers. Same thing for the Pentagon...

Obviously the takeovers were already complete, and they would have crashed somewhere, but it's curious to me to think what have happened if it hadn't been a "clear blue beautiful autumn day"

Note: First, if this has been discussed already, my apologies. Second, I'm not trying to start any debate over the event, especially conspiracy theories. I'm simply initiating a discussion about the effect of the weather on the outcome of that day.

29 replies: All unread, showing first 25:
 
User currently offlineOPNLguy From , joined Dec 1969, posts, RR:
Reply 1, posted (7 years 1 month 4 days 2 hours ago) and read 6874 times:

Quoting QXRamperMEII (Thread starter):
could 9/11 have happened the way it did if the weather had been bad?

It depends on what you mean by "bad"....

If there'd been a 100-foot overcast ceiling, very doubtful.

If there'd been a 2,000 overcast ceiling, they probably still could have hit their targets.

Same thing with visibilities, less than a couple of miles doubtful, anything more probably so..


User currently offlineWestJetYQQ From Canada, joined Jan 2007, 2987 posts, RR: 5
Reply 2, posted (7 years 1 month 4 days 2 hours ago) and read 6839 times:

Quoting OPNLguy (Reply 1):
It depends on what you mean by "bad"....

If there'd been a 100-foot overcast ceiling, very doubtful.

If there'd been a 2,000 overcast ceiling, they probably still could have hit their targets.

Same thing with visibilities, less than a couple of miles doubtful, anything more probably so..

 checkmark 

Sounds about right.



Will You Try to Change Things? Use the Power that you have, the Power of a Million new Ideas.
User currently offlineWingedMigrator From United States of America, joined Oct 2005, 2212 posts, RR: 56
Reply 3, posted (7 years 1 month 4 days 2 hours ago) and read 6805 times:

Quoting QXRamperMEII (Thread starter):
could 9/11 have happened the way it did if the weather had been bad?

Of course not. It would have been 9/13 or 9/14 or whichever next clear blue beautiful autumn weekday.


User currently offlineN844AA From United States of America, joined Jul 2003, 1352 posts, RR: 1
Reply 4, posted (7 years 1 month 4 days 2 hours ago) and read 6760 times:

Quoting QXRamperMEII (Thread starter):
Obviously the takeovers were already complete, and they would have crashed somewhere, but it's curious to me to think what have happened if it hadn't been a "clear blue beautiful autumn day"

Fascinating question. As OPNLguy quite correctly noted, it would have depended on many factors. I may pull out my copy of the 9/11 Commission Report, and see if there's anything along these lines the commission considered.

I've always thought one saddest ironies of that day was how beautiful it dawned. I hadn't yet moved to New York at that point, but the weather in Austin that day was gorgeous. Odd how something like that sticks in your mind in the face of abject tragedy.

I can't help but feel certain parallels with the debris track of the Columbia as it passed exactly over my family's house and my future wife's house in North Texas. I'd had a livelong fascination with the manned space program, and know that one of our orbiters had broken up 200,000 feet above my home was a twist of the knife in an already deep wound that day. That's another morning I'll never forget.  Sad

Quoting WingedMigrator (Reply 3):
Of course not. It would have been 9/13 or 9/14 or whichever next clear blue beautiful autumn weekday.

Undoubtedly they would have tried again, unless they had already taken control of the aircraft before encountering inclement conditions. The day still would have been terribly tragic, but maybe lives could have been saved. Maybe. Or maybe -- just maybe -- a delay in the plan would have led to its discovery.



New airplanes, new employees, low fares, all touchy-feely ... all of them are losers. -Gordon Bethune
User currently offlineNASCARAirforce From United States of America, joined Feb 2005, 3178 posts, RR: 4
Reply 5, posted (7 years 1 month 4 days 2 hours ago) and read 6760 times:

Quoting WingedMigrator (Reply 3):
Of course not. It would have been 9/13 or 9/14 or whichever next clear blue beautiful autumn weekday.

Yeah but didn't they have the flights booked a few days ahead? They didn't buy the tickets to fly on the planes the day of 9/11 did they?


User currently offlineNAV20 From Australia, joined Nov 2003, 9909 posts, RR: 36
Reply 6, posted (7 years 1 month 4 days 2 hours ago) and read 6751 times:

Quoting QXRamperMEII (Thread starter):
As I understand it, a few of the hijackers had rudimentary flying skills, enough to keep 757s and 767s flying along. After the takeover, they navigated visually to the targets and ran into them...

They will certainly have had more than 'rudimentary' skills; it has been established that some of them had licences and had taken lessons and practised with simulators for years.

The operations involved much more than a few minutes of 'flying visual' - if you follow the 'reconstructed' flightpaths on here (from a conspiracy site but sourced to "USA Today') you will see that one of the aircraft (North Tower) was navigated down from Canada via Albany, one (South Tower) followed the planned flightpath to a waypoint south-west of NYC and then turned back north-east; and one (Pentagon) followed the planned course far into West Virginia (possibly making a 'practice deviation' on the way) before turning back.

http://www.public-action.com/911/4flights.html

This suggests to me that the hijacker-pilots knew how to use the autopilots and the normal navigation aids (VORs, NDBs, GPS) and only switched to manual control at the last moment, when they could see the buildings.

The flightpath of the Pentagon attack is especially interesting as the aeroplane appears to have flown over Dulles Airport, continued north-east into Maryland, turned back south-east (directly over the White House), flown straight over Reagan National, and then executed a 270-degree turn over Arlington and hit the Pentagon. I found this 'reconstruction' of that flight carried out by an ex-pilot/navigator (not the 'conspiracy' type):-

http://www.thepowerhour.com/911_analysis/steves-analysis.htm

The only area where I disagree with 'Steve' is that he assumes that the hijacker was 'flying visual.' I suspect that, for the attack run, the hijacker used the autopilot to follow the ILS beam on one of Reagan's main runways; or alternatively track in to the Reagan VOR. As 'Steve' also points out, the 270-degree turn is the right sort of radius for a 'normal' turn -so this, again, could have been carried out using the autopilot.

Please don't anyone think that I'm a conspiracy nut. I just like, as far as possible, to work out what really happened for myself. Everything I've found suggests, to me anyway, that 9/11 was exactly what the official side says it was. An exceptionally well-planned terrorist attack.



"Once you have flown, you will walk the earth with your eyes turned skywards.." - Leonardo da Vinci
User currently offlineIAHFLYR From United States of America, joined Jun 2005, 4790 posts, RR: 22
Reply 7, posted (7 years 1 month 4 days 1 hour ago) and read 6721 times:

I'd like to believe that had the east coast and Great Lakes area been less than beautiful weather the people that took control of the airplanes would never have found their targets.

Finding a specific location not well. never mind...........I do not care to go further with my thoughts on this as it pisses me off too much to even give some ill minded group a thought process.



Any views shared are strictly my own and do not a represent those of any former employer.
User currently offlineSpacecadet From United States of America, joined Sep 2001, 3611 posts, RR: 12
Reply 8, posted (7 years 1 month 4 days 1 hour ago) and read 6672 times:

The tops of the twin towers were very often shrouded in clouds. Like this: http://www.flickr.com/photos/beija/243997357/

If that was the case that day, I think they'd have had a tougher time of it. They could have still flown under the clouds (depending on how low the ceiling was), but it would have required a lot more precision for them to avoid other obstacles on the way. And I have doubts that they'd have ever made it there to begin with - they flew at several thousand feet most of the way, and I don't know if they'd have had the skill or awareness to fly and visually navigate hundreds of miles at 500 feet. You lose a lot of your situational awareness at that low of an altitude.

A lot of things went exactly their way that day; think of all the other terror plots that were either foiled or just went wrong one way or another, including the other attack on the WTC in 1993. The weather was certainly in the terrorists' favor. If it hadn't been, at the very least it wouldn't have been as easy, and every variable that goes against someone is just another increased chance for a mistake or other potential failure.



I'm tired of being a wanna-be league bowler. I wanna be a league bowler!
User currently offlineLTBEWR From United States of America, joined Jan 2004, 13040 posts, RR: 12
Reply 9, posted (7 years 1 month 4 days 1 hour ago) and read 6651 times:

One possible reason for chosing Tuesday,9/11 for the attacks the aircraft and flighs chosen on a Tuesday was that they were transcon flights with full loads of fuel but a low pax loads. It is too bad that the skies over Manhattan were 'severe clear' at the time of the attacks, but that was part of the terrorists obscene plans. I speculate that if there if the weather preveneted the acts on 9/11, they would have delayed to Wednesday 9/12 or a week later.

User currently offlineKhelmDTW From United States of America, joined Jun 2007, 269 posts, RR: 0
Reply 10, posted (7 years 1 month 4 days ago) and read 6556 times:

I think it may have still happened, but getting all the planes back on the ground would have been more difficult. They say the clear weather around the country is what helped land all the airplanes in a matter of hours.


In Thrust We Trust
User currently offlineDeskflier From Sweden, joined Jan 2007, 537 posts, RR: 0
Reply 11, posted (7 years 1 month 3 days 21 hours ago) and read 6433 times:

While we are on the "what if..."-track: What if the terrorists had chosen an old concrete building like Empire State instead of the relatively modern steel and glass WTC? Would this as well have come tumbling down? Or would the aircraft have got stuck with just the nose inside the building?

OK, this is maybe more of a construction question than an aircraft question, but if there is anyone among the A.net community who has any insight, please share some of Your knowledge.



How can anyone not fly, when we live at a time when we can fly?
User currently offlineMD80fanatic From United States of America, joined Apr 2004, 2660 posts, RR: 9
Reply 12, posted (7 years 1 month 3 days 20 hours ago) and read 6353 times:

Weather forecasting, it's an amazing science.

We (the US) used it to predict the weather on Omaha beach prior to the D-Day invasion. We used it regularly in Vietnam and Iraq as well. It seems reasonable that the hijackers might have checked the national news a week prior to the attack in order to get an idea of the conditions they would be flying through. Unless they actually were the bumbling idiots they were portrayed to be, checking the boob tube would be a prerequisite.


User currently offlineEirbus06 From Ireland, joined Apr 2006, 253 posts, RR: 0
Reply 13, posted (7 years 1 month 3 days 20 hours ago) and read 6311 times:

If they(terrorist hijackers) had navigated to new york and could'nt see the twin towers due to weather,then

1) what was the time frame for the fighter jets to get to them?

2) And if the fighter jets had reached them(terrorist hijackers)over new york,could they have shot them down.

R.I.P to all 2,976 people.  Sad


User currently offlineBennett123 From United Kingdom, joined Aug 2004, 7475 posts, RR: 3
Reply 14, posted (7 years 1 month 3 days 19 hours ago) and read 6210 times:

IMO finding Manhattan would be fairly simple, if you know the rough bearing from the hijack point.

Clearly the wind bearing/strength has a effect but cities like NY/London etc are not easily hidden.

Unless visability was really bad, I think that they were going to find Manhatten, if not the Towers, then the Empire State, Crysler, Building, Wall Street. There are just too many targets not to hit something.

As for the Pentagon, you would need heavy fog not to find it.

It is a low building, (relatively) and the shape is effectively unique.

In conclusion, unless there was really heavy weather, then finding their targets was fairly straightforward.


User currently offlineNAV20 From Australia, joined Nov 2003, 9909 posts, RR: 36
Reply 15, posted (7 years 1 month 3 days 18 hours ago) and read 6159 times:

Quoting Deskflier (Reply 11):
While we are on the "what if..."-track: What if the terrorists had chosen an old concrete building like Empire State instead of the relatively modern steel and glass WTC? Would this as well have come tumbling down? Or would the aircraft have got stuck with just the nose inside the building?

We know from experience, Deskflier - a B25 medium bomber flew into the Empire State Building in 1945. The damage was similar - the aeroplane burying itself in the building, engines etc. busting right through, a great deal of structural damage and big fires.

http://images.google.com.au/imgres?i...m%3D10%26um%3D1%26hl%3Den%26sa%3DN

There were differences of scale, of course - this was only a ten-ton aeroplane with a minimum fuel load (it was only on a 'hop' from La Guardia to Newark), not a 150-ton jetliner with a full load of fuel. And it was only travelling at perhaps 120 knots, less than half the speed of the 9/11 aircraft. But I think it is safe to say that the results had the 9/11 buildings been concrete-framed would have been similar - indeed, I believe that the Pentagon is concrete-framed.

Whichever type of construction is used, the strength of modern buildings is in their frames, not their cladding. The WTC towers were 'curtain-walled,' meaning that the cladding consisted of a light structure, largely consisting of glass, whose main function was to keep out the rain and wind. But the masonry cladding of the Empire State, though it might look more 'massive,' will also have little or no structural role, beyond supporting its own weight.



"Once you have flown, you will walk the earth with your eyes turned skywards.." - Leonardo da Vinci
User currently offlineBongodog1964 From United Kingdom, joined Oct 2006, 3536 posts, RR: 3
Reply 16, posted (7 years 1 month 3 days 18 hours ago) and read 6125 times:

Quoting NAV20 (Reply 15):
Whichever type of construction is used, the strength of modern buildings is in their frames, not their cladding. The WTC towers were 'curtain-walled,' meaning that the cladding consisted of a light structure, largely consisting of glass, whose main function was to keep out the rain and wind. But the masonry cladding of the Empire State, though it might look more 'massive,' will also have little or no structural role, beyond supporting its own weight.

Nearly correct but not quite !!!

The Empire State is steel framed not concrete, you are correct however in stating that the masonry cladding has no structural role. The stone cladding for each floor is directly supported by the steelwork; all the strenght being in the steel uprights.

The WTC curtain walling was the primary loadbearing structure. The distinctive latticework held the building up, in order that the interior could have the large unobstructed open spaces that large occupiers now want. The glazing fitting between the structural girders.

I never saw the WTC, but having visited the Empire State Building, and been suprised at the small area of the upper floors, I could forsee a large plane passing clean through it possibly even amputating everything higher than the point of impact. A further consideration is that the WTC were pure towers with the same area on every floor; the Empire State is stepped in at a number of levels, thus any falling debris would land on terraces lower down; which in itself could cause further structural problems.


User currently onlineSEPilot From United States of America, joined Dec 2006, 6837 posts, RR: 46
Reply 17, posted (7 years 1 month 3 days 17 hours ago) and read 6095 times:

I strongly suspect, as others have pointed out, that the hijackers were not only capable of flying the planes but also of getting weather reports. I'm sure that was a factor in the day they chose; they had made dry runs before and if weather had turned out bad they could have just either not used their tickets or turned it into another dry run.


The problem with making things foolproof is that fools are so doggone ingenious...Dan Keebler
User currently offlineNAV20 From Australia, joined Nov 2003, 9909 posts, RR: 36
Reply 18, posted (7 years 1 month 3 days 16 hours ago) and read 5986 times:

'A' propos' of 'flying ability,' this amazing shot just before the impact with the South Tower (from a press helicopter) tells the 'whole story' for me, and may interest others.

http://www.cooperativeresearch.org/e..._flight175_hits2050081722-9061.jpg

The smoke from the burning North Tower shows that the breeze was from the north-west. The normal way of allowing for a wind is to 'crab,' that is, angle the nose of the aeroplane not where you want to go, but far enough into the wind to cancel out the drift.

That wasn't done in this case - the aeroplane is 'off-line' and is clearly banking sharply to the left at the last moment, to avoid missing the building altogether. The fairly extreme wing-flex suggests that the pilot was hauling hard back on the yoke as well - doing everything he could to tighten the turn.

Further, the bank angle is over 45 degrees - far more than the 30 degrees that is all that an autopilot would normally apply. That strongly suggests to me that:-

a) the aeroplane was being flown by a human pilot, not some kind of electronic guidance system actuating the autopilot; and

b) said pilot, even though he must have had some knowledge, was a half-trained amateur rather than any sort of qualified pilot or professional.

Seems to me that that single shot validates the official account, and debunks all the conspiracy theories?

[Edited 2007-06-29 14:45:43]


"Once you have flown, you will walk the earth with your eyes turned skywards.." - Leonardo da Vinci
User currently offlineRandyWaldron From United States of America, joined Mar 2006, 324 posts, RR: 3
Reply 19, posted (7 years 1 month 3 days 16 hours ago) and read 5902 times:

Quoting QXRamperMEII (Thread starter):
what if the weather was crap and they couldn't see them?

What I've noticed is that none of these responses has actually answered your question. Obviously none of the people who responded to your initial posting have any idea about the Flight Management System and navigational functions of those airplanes. In short answer to your question, yes, it is theoretically possible.

The INS (Intertial Navigation System) feature of the Boeing FMS allows the pilots to create ficticious waypoints based upon longitutde and latitude. They could have programmed the coordinates of the WTC into those FMS "boxes" and simply flown towards the created waypoints either by hand or by using the autopilot LNAV feature. In fact, any airplane with a rudimentary LORAN system (yes, LORAN is still around) can fly to a waypoint constructed using latitiude and longitiude only. INS and GPS navigate much more accurately than LORAN, but, nonetheless, it is possible.

Personally, I don't see how these men navigated these airplanes without some knowledge and use of the FMS, HSI and nav radios.



"Flaps 20, gear down, landing checklist please..."
User currently onlineSEPilot From United States of America, joined Dec 2006, 6837 posts, RR: 46
Reply 20, posted (7 years 1 month 3 days 14 hours ago) and read 5812 times:

Quoting RandyWaldron (Reply 19):

Personally, I don't see how these men navigated these airplanes without some knowledge and use of the FMS, HSI and nav radios.

They probably had some knowledge but that does not imply that they could have found their targets without visual reference. Hitting a building blind is going to be a challenge even for a seasoned pilot, which as NAV20 points out, these men clearly weren't. How much knowledge and skill they actually had is pretty difficult to determine at this point. Unfortunately they had enough for the task that they had appointed for themselves, and that is what really matters.



The problem with making things foolproof is that fools are so doggone ingenious...Dan Keebler
User currently offlineMika From Sweden, joined Jul 2000, 2862 posts, RR: 4
Reply 21, posted (7 years 1 month 3 days 14 hours ago) and read 5744 times:

Quoting Eirbus06 (Reply 13):
2) And if the fighter jets had reached them(terrorist hijackers)over new york,could they have shot them down.

And perhaps more importantly; would they have shot them down? Please correct me if i'm wrong but wasnt that routine something that came from 9/11? Before that i think that engaging a civilian airliner with live weapons would have been something that the authoroties never could have thought about doing. Before 9/11 a hijacking was a relatively undramatic event (relative to what happened on 9/11 anyways) in the sense that usually a hijacking is done to meet some kind of demands, not to actually use the plane as a missile.

I could be wrong about this though.


User currently onlineSEPilot From United States of America, joined Dec 2006, 6837 posts, RR: 46
Reply 22, posted (7 years 1 month 3 days 13 hours ago) and read 5685 times:

Quoting Mika (Reply 21):

And perhaps more importantly; would they have shot them down? Please correct me if i'm wrong but wasnt that routine something that came from 9/11? Before that i think that engaging a civilian airliner with live weapons would have been something that the authoroties never could have thought about doing.

Exactly right; this is part of why it took so long to scramble the fighters. Even when people at Defense realized that these were no ordinary hijackings they had to get Presidential (or at least Vice-Presidential) authority to shoot them down, and by that time it was far too late. The whole system was revised after that.



The problem with making things foolproof is that fools are so doggone ingenious...Dan Keebler
User currently offlineVC10BOAC From United States of America, joined Feb 2004, 402 posts, RR: 0
Reply 23, posted (7 years 1 month 3 days 13 hours ago) and read 5656 times:

Quoting Bongodog1964 (Reply 16):
The WTC curtain walling was the primary loadbearing structure. The distinctive latticework held the building up, in order that the interior could have the large unobstructed open spaces that large occupiers now want. The glazing fitting between the structural girders.

Sorry about taking this thread off topic but this is right up my alley. (Check profile)

First consider what brought down the WTC. It was a combination of several factors that created the "perfect storm" so to speak and not just the initial impact.

1. The construction. As rightly pointed out, much of the steel support was around the outside of the structure. There was also an inner core. The impact compromised both the outer and inner supports. Structures like these are built with redundancies, meaning that if some supports are compromised, others will take over in supporting their loads which is exactly why the buildings initially stood after the impact.

2. Heat. The aircraft were full of fuel and the resulting fire and heat softened or melted the remaining structural supports, already overstressed after taking upon the additional loads of the supports initially destroyed. They ultimately failed.

3. Impact. After the supports failed where the planes had impacted, the floors above came crashing down, and the impact from the floors above caused the supports further down to fail or buckle, resulting in a "pacnake" effect, causing the buildins to come down the way they did.

One could only speculate if the same would have happened with the Empire State Building. My opinion is that it would have been less likely (still possible though) given the following facts about the ESB's construction;

a. The supporting steel is more evenly distributed and not as concentrated as in the WTC making it likely that a less percentage of the total support would have been compromised.

b. As mentioned before, the impact from the floors above colapsing would be less in relation to the rest of the building, given the fact that the cross sectional area decreases as the building gets higher.

c. The exterior cladding of the ESB (much concrete) has a lot more concrete than the WTC (mostly glass) which would absorb some of the impact of the aircraft, offering more protection to the interior supports.

Just my opinion. Again I apologise for going off topic but someone asked...


User currently offlineN844AA From United States of America, joined Jul 2003, 1352 posts, RR: 1
Reply 24, posted (7 years 1 month 3 days 12 hours ago) and read 5588 times:

Quoting SEPilot (Reply 22):
Exactly right; this is part of why it took so long to scramble the fighters. Even when people at Defense realized that these were no ordinary hijackings they had to get Presidential (or at least Vice-Presidential) authority to shoot them down, and by that time it was far too late. The whole system was revised after that.

And of course you can see a de facto revision of the traditional response to hijackers that morning: once the UA 93 passengers heard about what these hijackings actually entailed, the old rule of "keep your head down and give them what they want" ceased to be operative. All it took was that 45 minute delay. Obviously this isn't entirely applicable to the national command-and-control structure, but the principles are similar.

I doubt there will ever again be a successful "fly me to Cuba"-type hijacking in this country. The passengers simply won't allow it to happen.



New airplanes, new employees, low fares, all touchy-feely ... all of them are losers. -Gordon Bethune
25 Post contains images Eirbus06 : Very true! If somebody sneezes or coughs on an aircraft nowadays,the whole cabin is edgy.
26 Post contains images YULWinterSkies : You forgot how much planning there has been behind that attack. 9/11 has a symbol in itself too. 9-1-1. Which is also the # of days after 9/11/01 the
27 DeltaGuy : Only way to do it....psycho-suicidal "skills" aren't programed into the system. There'd be no way for it to fly into the towers via LNAV or HDG, and
28 KBOS : The one saving grace about the severe clear on 9/11 was how it was a great help to ATC after the tragedy. Imagine if there was a large part of the cou
29 ANCFlyer : This is no longer weather or aviation related . . . . Thread is done.
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