# Jet and WTC **URL:** \ **Category:** Factual Questions\ **Created:** [December 15, 2002, 12:05am UTC](https://boards.straightdope.com/t/jet-and-wtc/142806 "2002-12-15T00:05:05Z")\ **Posts on this page:** 15\ **Page:** 2
**Author:** ![Desmostylus](https://avatars.discourse-cdn.com/v4/letter/d/c57346/32.png) [@Desmostylus](https://boards.straightdope.com/u/Desmostylus)\ **Post date:** [December 15, 2002, 12:04pm UTC](https://boards.straightdope.com/t/jet-and-wtc/142806/21 "2002-12-15T12:04:28Z")
**Armilla** , I think that your back-of-the envelope calcs are probably more sensible than the calcs in the site you referred to, because your calcs allowed for some debris being retained in the building, and some escaping. The “force on the building” approach using momentum is flawed. The impact force isn’t comparable to wind loading. The impact didn’t cause a uniform deformation over the entire structure, it _broke_ things. ---
**Author:** ![Armilla](https://avatars.discourse-cdn.com/v4/letter/a/e19b73/32.png) [@Armilla](https://boards.straightdope.com/u/Armilla)\ **Post date:** [December 15, 2002, 12:32pm UTC](https://boards.straightdope.com/t/jet-and-wtc/142806/22 "2002-12-15T12:32:22Z")
> [@](#): > > \*Originally posted by Desmostylus \* > The “force on the building” approach using momentum is flawed. The impact force isn’t comparable to wind loading. The impact didn’t cause a uniform deformation over the entire structure, it _broke_ things. Quite true. The physics of the actual collision must be mind-bogglingly complex when you take into account the effects of the fuel explosion, the actual structure of the tower with its load bearing core and suspended walls and the distribution of the debris. The wind loading is the day-to-day stress the building is designed to withstand, and no doubt has a large safety margin, but I think it helps to put the forces of the collision into some perspective since it’s pretty hard to visualise the sheer scale of the impact. ---
**Author:** ![MSU\_1978](https://avatars.discourse-cdn.com/v4/letter/m/ac8455/32.png) [@MSU\_1978](https://boards.straightdope.com/u/MSU_1978)\ **Post date:** [December 15, 2002, 2:45pm UTC](https://boards.straightdope.com/t/jet-and-wtc/142806/23 "2002-12-15T14:45:54Z")
I think Armilla has the physics pretty well nailed on this. But what brought the towers down was the fire. Obviously the terrorists knew that going twice as fast has four times the energy, but if those planes weren’t full of fuel the towers would have stood. ---
**Author:** ![DougC](https://avatars.discourse-cdn.com/v4/letter/d/7feea3/32.png) [@DougC](https://boards.straightdope.com/u/DougC)\ **Post date:** [December 15, 2002, 3:42pm UTC](https://boards.straightdope.com/t/jet-and-wtc/142806/24 "2002-12-15T15:42:04Z")
- - - General rambling here: …some time ago I saw some true crime/hijacking show on cable TV that told about a hijack where the guy dove a plane straight into the ground from altitude. They identified the hijacker because they found the pistol he used, and found some of the skin from his finger still stuck to the trigger. They also found a note in the debris he had written about “airline management having no mercy for him, and how he would have no mercy for them”. The flight he picked had a couple airline board members riding on it (that was why he chose it, they guessed), and he was a airline employee of some sort who had gotten fired a day or two before, and he still had all his ID’s and could get on board without being searched. They guessed that he shot the pilots, sent the airplane into a nose dive and held it there, and shot himself just before impact. The estimate of impact speed was _over 700 mph_. ~ ---
**Author:** ![Duck\_Duck\_Goose](https://avatars.discourse-cdn.com/v4/letter/d/50afbb/32.png) [@Duck\_Duck\_Goose](https://boards.straightdope.com/u/Duck_Duck_Goose)\ **Post date:** [December 15, 2002, 3:50pm UTC](https://boards.straightdope.com/t/jet-and-wtc/142806/25 "2002-12-15T15:50:08Z")
Um, IANA physicist, but if he drilled a plane into the ground from altitude at 700 mph, how is it that a note survived the crash? Not to mention skin still stuck to the trigger? My “oh come on” alarms are going off. In other words–cite? ---
**Author:** ![Hail\_Ants](https://avatars.discourse-cdn.com/v4/letter/h/dc4da7/32.png) [@Hail\_Ants](https://boards.straightdope.com/u/Hail_Ants)\ **Post date:** [December 15, 2002, 11:26pm UTC](https://boards.straightdope.com/t/jet-and-wtc/142806/26 "2002-12-15T23:26:03Z")
That hijacking/crash is [well documented.](http://www.airdisaster.com/special/special-pa1771.shtml) The note surviving wasn’t the hard part (a piece of paper doesn’t have a lot of momentum even going 700 mph because it still has very little mass). Finding it was, but they did. And the remains of the revolver with a bit of the guy’s skin on it. They knew what to look for because they heard what happened on the CVR. ---
**Author:** ![mangeorge](https://avatars.discourse-cdn.com/v4/letter/m/d78d45/32.png) [@mangeorge](https://boards.straightdope.com/u/mangeorge)\ **Post date:** [December 17, 2002, 12:06am UTC](https://boards.straightdope.com/t/jet-and-wtc/142806/27 "2002-12-17T00:06:42Z")
How did they know the final shot was suicide? Peace, mangeorge ---
**Author:** ![tcdaniel](https://avatars.discourse-cdn.com/v4/letter/t/b9bd4f/32.png) [@tcdaniel](https://boards.straightdope.com/u/tcdaniel)\ **Post date:** [December 17, 2002, 3:19am UTC](https://boards.straightdope.com/t/jet-and-wtc/142806/28 "2002-12-17T03:19:31Z")
> [@](#): > > \*Originally posted by Hail Ants \* > \*\*Both planes were traveling much too fast for their altitude. This was immediately noticed by the ATCs. > > Its been assumed (obviously) that since the terrorists wanted to inflict as much damage as they could, they firewalled the throttles as they approached the towers. DUH! > > But I believe the 2nd jet was only estimated to be going about 520 mph and the VNE (velocity not to exceed) of a 757 is listed as 590 mph. So I don’t think it was that close to ripping the wings off. \*\* There must be laws to stop terrorist from flying hijacked planes TOO FAST for conditions! Take away their pilots license at least. They needed more training perhaps. They endangered all those passengers lives. Way too much thinkin’ goin on here, but it is interesting. The planes were destined to disintigrate no matter how fast or slow or how high or how low with those maniacal operators. All safety procautions went out the window that morning. ---
**Author:** ![lexen](https://avatars.discourse-cdn.com/v4/letter/l/b2d939/32.png) [@lexen](https://boards.straightdope.com/u/lexen)\ **Post date:** [December 17, 2002, 2:06pm UTC](https://boards.straightdope.com/t/jet-and-wtc/142806/29 "2002-12-17T14:06:38Z")
Just a quick thought. What did the most damage to the building at the moment of inpact ? I thought a plane is mostly light aluminium foil with some hard parts (engines) attached. Even a large plane couldn’t damage the core structure of such a building, because it would just crumple up. Isn’t the damage done from the only part that wasn’t compresable, the fuel, entering the building at very high speed, and acting as a high pressure pump ? ---
**Author:** ![Tuckerfan](https://avatars.discourse-cdn.com/v4/letter/t/eada6e/32.png) [@Tuckerfan](https://boards.straightdope.com/u/Tuckerfan)\ **Post date:** [December 17, 2002, 2:15pm UTC](https://boards.straightdope.com/t/jet-and-wtc/142806/30 "2002-12-17T14:15:10Z")
> [@](#): > > \*Originally posted by lexen \* > \*\*Just a quick thought. What did the most damage to the building at the moment of inpact ? I thought a plane is mostly light aluminium foil with some hard parts (engines) attached. Even a large plane couldn’t damage the core structure of such a building, because it would just crumple up. Isn’t the damage done from the only part that wasn’t compresable, the fuel, entering the building at very high speed, and acting as a high pressure pump ? \*\* Ever seen the photo of a **straw** driven into a tree by a tornado? Or of the 2X4 sticking out of the side of a brick wall? At high enough speed, it pretty much doesn’t matter _what_ something’s made out of, it’s going to go through whatever it hits. ---
**Author:** ![Beastal](https://avatars.discourse-cdn.com/v4/letter/b/a183cd/32.png) [@Beastal](https://boards.straightdope.com/u/Beastal)\ **Post date:** [December 17, 2002, 2:23pm UTC](https://boards.straightdope.com/t/jet-and-wtc/142806/31 "2002-12-17T14:23:06Z")
Flying that quickly, were they using only naked eye sight to guide the planes in to the towers? Both planes hit almost dead middle… Being off just a few cm when 500 yards away would result in a miss, and flying so fast, would be hard to correct? ---
**Author:** ![Hail\_Ants](https://avatars.discourse-cdn.com/v4/letter/h/dc4da7/32.png) [@Hail\_Ants](https://boards.straightdope.com/u/Hail_Ants)\ **Post date:** [December 17, 2002, 10:22pm UTC](https://boards.straightdope.com/t/jet-and-wtc/142806/32 "2002-12-17T22:22:43Z")
**tcdaniel** > [@](#): > > Way too much thinkin’ goin on here, but it is interesting. The planes were destined to disintigrate no matter how fast or slow or how high or how low with those maniacal operators. All safety procautions went out the window that morning. Um, I’m not sure what you’re criticizing here. The OP was asking if the plane might have come apart before it hit (i.e. the terrorists might have failed), and the general concensus is no. **Beastal** > [@](#): > > Flying that quickly, were they using only naked eye sight to guide the planes in to the towers? > Both planes hit almost dead middle… Being off just a few cm when 500 yards away would result in a miss, and flying so fast, would be hard to correct? For their (believe me, no pun intended) final approach, yes, they did it by eye (how else could they have?) Again, not to make light of it, but sometime after it happened I (like a lot of other people I’m sure) tried doing it on MS Flight Sim. It includes NYC (they have since taken TWC out) and either a 757 or 767. It’s not easy. Big jets manuver like barges and going 500+ mph even TWC comes up pretty fast. I feel bad saying that, because I don’t want to be seen as showing any admiration for the murderous, inhuman, cowardly (Bill Mahr was wrong) scumbags who did it… ---
**Author:** ![Broomstick](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/broomstick/32/246_2.png) [@Broomstick](https://boards.straightdope.com/u/Broomstick)\ **Post date:** [December 18, 2002, 12:15am UTC](https://boards.straightdope.com/t/jet-and-wtc/142806/33 "2002-12-18T00:15:06Z")
> [@](#): > > \*Originally posted by Hail Ants \* > > > [@](#): > > > > _Originally posted by Beastal_ > > Flying that quickly, were they using only naked eye sight to guide the planes in to the towers? > > Both planes hit almost dead middle… Being off just a few cm when 500 yards away would result in a miss, and flying so fast, would be hard to correct? > > **Beastal** For their (believe me, no pun intended) final approach, yes, they did it by eye (how else could they have?) Keep in mind, **Beastal** , that is wasn’t like aiming a gun and firing a bullet - the murderous scum (apologies to pond life for the comparison) were able to make small corrections in the trajectory up until the moment of impact. Yes, being off X amount at Y distance can result in a miss, but positioning the airplane precisely in space and time is something all pilots work towards. Keep in mind, too, that these [expletive deleted] no doubt practiced this manuver to one degree or another, with tools such a MS Flight Simulator, so that when they real deal was in motion they were much more likely to succeed. Even so, one of the airplanes had to make a sizable course correction in the last few seconds (hence the OP). > [@](#): > > I feel bad saying that, because I don’t want to be seen as showing any admiration for the murderous, inhuman, cowardly (Bill Mahr was wrong) scumbags who did it… I think it is possible to admit that, yes, the tactics employed were brilliant from a military strategy viewpoint, but also to NOT condone in any way their actual use in the real world. ---
**Author:** ![Walloon](https://avatars.discourse-cdn.com/v4/letter/w/fbc32d/32.png) [@Walloon](https://boards.straightdope.com/u/Walloon)\ **Post date:** [December 18, 2002, 12:17am UTC](https://boards.straightdope.com/t/jet-and-wtc/142806/34 "2002-12-18T00:17:07Z")
The account of the Pacific Southwest Airlines flight 1771 crash says: > [@](#): > > As the aircraft reached its cruising altitude of 29,000 feet, Burke calmly vacated his chair and made his way to the lavatory, dropping the air-sickness bag in his supervisor’s lap as he passed. Moments later, he emerged with the handgun, and immediately shot Thompson. If everyone aboard the plane died, and no part of the crash was larger than a square foot, - How did they know of the “calm” demeanor of Burke? - How did they know he used the lavatory before the shootings? - How did they know how long it was before he exited the lavatory and when he shot Thompson? I smell journalistic embellishment. ---
**Author:** ![Mr.Miskatonic](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mr.miskatonic/32/310_2.png) [@Mr.Miskatonic](https://boards.straightdope.com/u/Mr.Miskatonic)\ **Post date:** [December 18, 2002, 12:44am UTC](https://boards.straightdope.com/t/jet-and-wtc/142806/35 "2002-12-18T00:44:42Z")
> [@](#): > > \*Originally posted by Walloon \* > \*\*The account of the Pacific Southwest Airlines flight 1771 crash says: > If everyone aboard the plane died, and no part of the crash was larger than a square foot, > > - How did they know of the “calm” demeanor of Burke? > - How did they know he used the lavatory before the shootings? > - How did they know how long it was before he exited the lavatory and when he shot Thompson? > > I smell journalistic embellishment. \*\* Dunno, but here’s some [more info](http://www.airsafetyonline.com/accidents/special/murder.shtml) . Apparently, the flight recorder survived. [Previous page](https://boards.straightdope.com/t/jet-and-wtc/142806.md?page=1)