in chapter twelve we're going to be looking at the aircraft debris one of the main arguments against a large plane impact was there's too little debris speculate a plane crashed far from the wall on plane parts should be visible on the lawn some of the other open air crash sites speculate a plane hit a solid immovable object frequently at sandia crash is used as an example many of those parts turned to confetti as well as we'll see the new pearl harbor photo  shopped a crash plane outside and said this is what it should look like but the plane crashed in this case here what it meant crashed hundreds of feet and slid to just in front of the building if for this to actually have happened the confetti from the sand the crash test was an f four phantom into a four hundred sixty nine tons reinforced concrete block that was twenty three feet square by twelve feet thick with a total mass that was just huge so the impacting plane hit this the pentagon wall as we saw earlier was a very light wall relative had equivalent mass to the impacting plane seventy five tons versus on a ton plane so it would give and once the wall gave the plane only had to go off a few feet one hundred feet into the building for the entire plane to basically be swallowed up and disappeared as people had observed but when this is a sort of plane enter the weak wall and when they describe it they said the plane went through the wall no description of the plane shattering it was followed by the fireball and then the brief olling accounts in physics support the plane entering the pentagon some but not many identifiable plane parts have been recovered from the inside and a few from the outside the deceleration of the plane parts especially the left wing at column nine a and the adjacent steel window frame speaks volumes to what actually happened it tells of a violent event but one that speaks to the significant deceleration of the impacting mass disintegration of an entire wing of the confetti is not possible with these dynamics as evidence by the observed plastic deformation of these components and we can talk about the outside field in pristine one south of the impact point is one argument against the plane impact they there is the assessment that the engines would have doubts the lawn the a estimated that the top of the fuselage of the aircraft was no more than about twenty feet off the ground because a seven fifty seven body is twelve and a half feet in diameter the engine extend for a half feet below the aircraft body there'd be about three feet of clearance left for the plane if level in fact the left engine did hit the ground and did leave a mark this is the pristine lawn south of the impact point and from this you can see that there's not an engine scrape there's nothing that indicates that the plane actually hit the ground but in fact the plane hitting the ground was observed at the retaining wall and as i've mentioned previously that is as the engine came down because the center of the boat in area of column nine a it's a it's possible to determine that the plane wing hit at approximately mid height the several tree stump a column sixteen a severed at about five feet the left wing would be approximately proximately level to this point as the engine impacted the retaining wall the wing tips would have remained above the lawn no sign of the wing to touching would be expected this is a picture of the retaining wall gouges take in proximity perpendicular to column fourteen and you can see the severed tree stump in the background that's forty to about forty two feet from the diesel generator where the  right wing would have hit which is on the right type of spacing and as in the plane impact analysis that we've seen earlier these dimensions line up from the overhead perspective that i provided c is estimate the height is based on ninety percent of the first floor bearing the brunt of the damage and in this case here the plane size little bit misleading because of perspective and again we have an inset here showing col nine a where the left wing is going to hit we've got the retaining wall with the gouged kind of drawn in there we've got the stump of the tree and column sixteen shown and that's kind of the orientation if you take a look at the plain projection at all that is aligned with the column nine a on the left the bastion column not symmetric around the impact zone after the fireball witnesses said there were millions of pieces of wreckage and debris around the heliport the debris also rained down on highway twenty seven with some falling on the north side of the pentagon on the fort myer walking trail which was probably seen on the some of the photos almost all the debris fell to the north and west of the impact point of the large plane there are two broad classes of debris the first is dense debris it's amazing area limestone in small dense aircraft parts is also like to bring airplane fuselage fragments confetti like in what we've got dispersed pentagon research is really address the dispersed stone like pieces of debris many witnesses and photographers show the scene see the stone debris on washington boulevard and the security cameras capture the dense debris landing in the field of view of those security cameras talking about the light debris most of the discussion above the debris typically revolves around the small like confetti like air crash aircraft fragments is are characterized by a large surface area for their weight confetti like  is the typical description is also some larger fuselage pieces they also have large surface area for their weight there's also tree branches and twigs with leaves still attached these sort of encountered very large amounts of areas instance if traveling through stagnant velocity was if you want to take a real life example you can ask the question how far can you throw a stone if i can throw it so far but some people can throw a stone pretty far how far can you throw an empty beer can no matter how fast you throw it it's not going to go very far how far could you throw a small tree branch with the leaves on it not very far to much it there are two larger fuselage debris pieces that world we can talk about the travel north and west the heliport they have large surface area to weight ratio no want to show velocity will make these travel five hundred feet through stagnant air could not have been dispersed by reflection or rebound they would have had to been transported within a large moving air mass caused by the air mass following the aircraft which is simply air refilling the void where the plane had just traveled through and this is going to be a high speed trailing air mass because the plane was going five hundred forty or five hundred sixty miles an hour after impact in the fireball the debris traveled mostly north because the momentum and the trailing air mass most debris ended up traveling northward not southward and here i've shown kind of the reflection pattern that for a lot of the debris kind of going up been kind of over and then there's a trailing air mass that is following the plane and it is coming in at the same speed as the plane and then when the plane goes inside it still has that same momentum here i've done i've just got the trailing air mass following that had been following the plane and once it hits the wall it's going to do a couple of things has one of it one of th that's going to do is go off to up and to the left or towards the heel port tower and also beyond it's also going to go up and over pushing the fireball away and it's also as reported by witnesses inside it's going to go some of it's going to create wins inside the building that are not explosive but persistent one of the witnesses inside talks about having to hole up her hand as a white board apparently immobile white board starts to slide across the room at her so that was interesting just one of the many interesting discussions about  what it was like to be on the inside in the wasn't an explosive event and in this particular example this witness but it was the chalkboard just come in kind of coming in or as the air was blowing through the building still is a fact of aerodynamics that there is a trailing form dragons and there are the never resistance to motion resistance to motion through a fluid it depends on the shape of the aircraft airflow around the aircraft will change the local velocities of the air moving the local air velocities translates to local pressures during pressure distribution around the aircraft will produce a resulting force on the body and the magnitude of the force is calculated by integrating that local pressure times the surface area around the entire body and what this results in as a fluid flow that's in the direction of travel relative to the stagnant fluid fluid that it's in now what we have here is a wing and alice's we're going to look at the change in relative pressures by the different colors and if you look at the bottom left hand side we see the red arrow so that's indicating relative stagnant and being air in that red zone is getting pushed forward it's kind of like a snowplow effect you can see how the pressure emanates from the the kind of the wing behind it and that is what we're looking at here and again this is all relative to the stagnant ambient air that we're concerned about what we have here is a sandia test in which we're looking at the upward and outward arc seeing debris as a result of the trailing air mass impinging upon a very large concrete block the you don't see any debris being reflected backwards you see it only going upwards and outwards mostly the light material it's mostly smoke and very small confetti like debris that is the stuff that is going up outward in all direction of course heavier parts may reflect to me do other things again you can see everything just kind of blowing up we're not word and there's no directional flow of the material back towards where the plane came from suggesting that the trailing air mass is actually creating a significant piece of the dispersion that we're looking at now we're going to take a look at it from the sun this is a slow motion and what you can to see is that the right wing even though it is a very  is built and set in orientation it is still dragging along a significant airflow and that's what is creating that dust and material going off to the right hand side of the block as you just saw trailing air mass even behind the wing an air in them dynamically designed for in the slide we're going to do is we're going to look a plane at a plane passing through a smoke screen and you going to be able to see the down wash from the plane going overhead it's going to be very violent pushing down of the air and then you going to see the vortexes of the wing tips beginning to form so it's a pretty remarkable low pass but it's not as low as they're violent now there's a description of this trailing air mass by penny eggless she says at the point where the fuselage at the wall is seemed to simply melt in the building ok i saw a smoke ring surround the fuselage it made contact with the wall and it appears as as a smoke ring that encircled the fuselage at the point of contact and it seemed to be several feet thick i later realized that it was probably the rubble of turning bits of plane in concrete actually probably grass clippings and other things  from the the law on both on the other side of washington boulevard as well as the pentagon lawn the churning smoke ring started at the top of the fuselage and simultaneously wrapped around bertha right and left sides of the fuselage to the underside where the calling rings crossed over each other and then coiled back up to the top then it started all over again only this time i also saw fire glowing in the within the smoke ring and that was what he had observed that's very consistent with both what we've just seen and what we would have expected this is a picture of some of the debris that was blown onto the heliport area the  begins to the right of the firefighters and it's in this image here but you can see the tree debris he can see the plane parts you can see all sorts of things and of course this is after the fire fighting for there's a lot of stuff that see and it also has some of the tree branches again tree branches still have the leaves on them you can't throw the stuff through stagnant air it has to be traveling through a  mass kind of like you go out and in a hurricane force winds throw something up in the air it's going to go and that's the type of when there was behind this plane which disperse this material in this one general this light debris location it rules out pre placed explosives alone absent a trailing air mass emanating from the southwest and explosion only would have dispersed debris to the north south and west more or less equal an explosion only cannot explain the dispersion of most abri in one direction explosions only a missile bomb p explosions exploding plane can explain this person of this light debris over the five hundred feet away from the impact area where the event internal and external explosives would inject material similar to this plus it would be able to explain the tree of columns sixteen how the base of it got whacked and kicked one hundred feet to the north there were these large pieces of wreckage again these have large surface area to carry the weight ratio here's a nother example of some small piece wreckage and tree branches near the firehouse again look at the leaves on the branches you can throw the stuff trailing airmass a lone proves a large plane impact plane is the only source of a large trailing air mass no significant wind on nine eleven capable nothing was capable of creating a large air mass movement on or otherwise calm when was september day  this must be the effect of a local air mass trailing large plane that hit the pentagon no other explanation fits this observation proves a large plane all myself here's another piece of a large overhead luggage rack although i don't know exactly what  there are two large pieces of debris that we're going to be taking a look at to introduce you to the first piece that we're going to be looking at we're going to be talking about what you see in the picture here this is the boeing seven fifty seven leaving wing slap  a lathe and if you take a close look you can see that there it's got some unique shapes first there is a defining arc to the out of piece and then there's an extension bar we're going to be wanting to make sure that we know what those are the next i'm going to do is take a look at what the wing slat actually does where it's where it's located on the plane and what you can see here is the wing slide is going to get retracted these are the things that you've seen and you can see the the large engine on the seven fifty seven right below there there is closed this is a large piece of debris and we're going to take a look at this a little closer but it is in fact a leading wing slap that's the tach from the impacted wing and it is after it would have hit light poles number one and number three here i've taken the piece of wing slide that was in the jig and placed it next to the wing slap it on the ground in about the best orientation i can and what  we've got the same arc we of course is a home is badly damaged and mangled and probably fell off the plane as it's going five hundred miles an hour and kind of crash on the ground and then you can see the the extension bar that i've highlighted there so you can see that both in the piece on the ground the debris piece and in the piece that was on the jig the location of this can be determined by taking a look at what is in the background of the picture if you go take a look at behind the tents what you can see is that there are people there are poems but mostly this the poems and there's a catenary wire and when you actually go and figure out where this actually is it's that located right about where this particular certainly the circle is under the tent in the catenary wire you can actually see it's near the bottom of the yellow arrow that's on the left hand side that's where the that's the cable it was seen so this is been located at a place that is very curious and it's if you take a look at per flight path and mark the light poles and you put where this thing is it's going to be in this area here and it's really hard to locate exactly where it was and when it hit the ground who knows where it hit and how much it slid whatever but this is about the area that it was located in and this is very consistent with it having been a piece of the wing slats that have been impacted by the light poles who then were damaged in fell off so no one has ever seen this before no one's actually known what this thing was where it was located and now you know it's a life piece of debris another piece of information that hasn't been out there and it's you can go check out and see where these pieces are by looking at a photograph yourself here's a picture that may be showing a picture of this large piece of debris the images are very clear but it suggests of the innocent in the right location here's another photo of of that large piece of debris from the south and it's caught by daryl donnelley in this particular case here's another picture of the large debris to the south it's from one of the two handheld videos of the pentagon after the event here's another picture that is going out to the north side we're going to be taking a look at this particular piece is actually a very interesting piece of debris this was apparently taken some point after from late later in the day we see here that there are some military people pentagon people running past this large piece of debris and you can see that the debris is in the shadow if you take a look at the image to the left field see that i've kind of drawn where the shadow might have been at this time based on other things that were happening at the at the time and it's also in front of a couple of the trees that i'm going to call a and b which you can he can see a b is a little bit harder to see but you can this is the location of it were another couple of pictures this is a photo by luke from fortunate to run across a couple of pictures that he took that actually have this piece of debris as its heart that captured it's usually obscured by something else but the sun moves a large piece of debris is no longer in the shadow of the pentagon or the control tower and then this is another view of it that's looking across the firefighting field you can see the diesel generator trailer and in the back the wires some of the wire spools and then turning on city in the background but you can see that this piece is standing up i think somebody has referred to it something in this area has have as having looked like a piece of landing gear but in fact you now have a pretty good idea what this large pieces now this piece as it's traveling there may have actually been captured in transit by the security cameras we're going to take a look at a couple of images in sequence and we can see that if you look behind the fireball in the back you see the fireball in the foreground kind of you see the  outline of the control tower and you see this bright spot to the left and it's moving this in the second picture we see it over here and over this is a about the location where it would be found resting the that was one of the security cameras the other one has also captured but it's not as as good you look at some landing gear parts the location of some of the largest structural massive pieces are shown here we've got landing gears we've got main wheels going to the bottom left hand side of the main wheel we've got obscured by the water we have to the right hand side we've got the main wheels kind of pointing where those would have been there's a main strut that is seen and some of the photos of  it when the pieces were photographed at the pentagon here's a picture of the landing gear shaft on the left hand side and on the right hand side we have what it would have looked like  in the working plane on the right hand side we see the double wheel rims that are shown here again on the working plane on the left and then we clearly see the kind of the double rim pieces that is required for free aircraft here's the same type of images the double rim on the main to the to the to the south i've highlighted the double lines for the for where the double rim would be now look at some engine parts of the boeing seven the two thousand the rolls royce was used by american airlines pratt when it was used on t w a which later merged with american airlines in two thousand and one earlier that earlier nytol earlier in the a rolls royce engine cutaway looks like this on the on the right hand side is can see the different components and just to the right of the cone is what appears to be  the the area where a piece of a rotor will be would have said here is just another version of the cutaway kind of highlighting the area where that rotor is that we're going to be see out in front of the pentagon during the this is another cutaway of the high pressure area you can see some of the inlet valves  high pressure this section of the of the engine and then here's the rotors some claim it's from a president in two thousand but it looks much more like the rolls royce rotor and there's nothing in the cross sense in the straw section of the panel in the two thousand that looks like that particular piece the therefore the engine parts appear to be from a rolls royce eleven five thirty five if the engine parts are from a pattern of two thousand the plane can't have been the in six forty for a seems unlikely that it would be a pratt when the two thousand  but i don't have the expertise sort of the shop drawings or photos and of course none of the serial numbers of the engine parts have been released although i'm sure that they were documented they have never been released and we call for those to be made available to the general public so that we can better understand which plane was actually used if in fact it was the and six for for a so after after nine eleven there was a significant amount of evidence sifting and looking for remains during the cleanup process debris was taken to the north parking to separate human remains for identification to gather evidence from the accident scene wish we could see that no comprehensive catalog of debris has ever been published and no serial numbers for parts in an extraordinary level of secrecy no success with requests for information for this type of here's some photos of the remains and evidence sifting to the north in the north parking  don't know what happened in any of the material another picture of the remains and evidence sifting very little information has been forthcoming on this very little as in the blogs or whatever so in chapter fourteen we're going to take a look at the april gallop lawsuit this is one of the highlighted areas exemplifies the poor quality research about the pentagon lawsuit claim there was no plane at the pentagon sort of the damage was caused by a missile and or explosives asserted that a full gallop walked out of the impact hole in the pentagon and no supporting evidence was present the claim that a full gallop walked out of the impact hole because it was included in the legal complaint has been cited as proof of no plane where april gallop was located one e five seventeen is absent in the nine eleven literature we don't really know where it is we can there is a vague it was in this area description but that's about it gallops legal team from i don't know supporting deposition or even a suggested path regarding travel to the impact room five one e five seventeen is highlighted in the middle and i've just drawn in a path to the entrance hole where she would be going out of the damaged office area down the hall into the fire into the breach traveling through this area and coming out  the hole it seems really implausible and doesn't jibe with anything that's been described contemporaneously with the nine eleven here's the entrance hole about three minutes after impact and now it's a massive inferno here's another photo of it a little bit later you can see that the fires are raging that the tree branches are in the way to have walked out of the pentagon through this area would have been a far more interesting story than what april gallop says it would be fighting through the fire and flames and burning trees and having walked into this firing thing from from down the hallway and if you take a look through the window actually the second one from the right you can actually see the fires on the inside in this office seems highly unlikely that anyone would go and walk out this particular hole here's the entrance hole minutes after the impact taken with the risk this is all aflame so here's what the law claims to cause and arrange for high explosive charges to be detonated inside the pentagon and or a missile of some sort to be fired at the building at about the time the wayward airliner supposedly a lot right there to give the false impression that hijackers had crashed the plane into the building as had apparently happened in new york and paragraph four in the attack on the pentagon in particular plaintive ver's that the official story hijacked plane crashed into the pentagon and exploded causing the plaintiff's injuries is false in fact the bombing was accomplished another way so as to limit the damage protect the defendants and only make it appear that a plane had crashed into the building paragraph six her desk was roughly forty feet from the point where the plane allegedly hit the outside wall and she sat down to work there was an explosion then another walls collapsed and the ceiling fell in hitting the head she was able to grab the baby and make her way towards the daylight showing through the blasted opening in the outside wall there was no airplane wreckage and no burning airplane fuel anywhere only rubble and dust so the disposition of the lawsuit  attorneys alternately were sanctioned for filing a factually unsupported case gallops attorneys were safe from ridicule because one of the judges in the appeals panel judge john walker was a cousin and george herbert walker bush still year of their appeal was blamed on nepotism and not the lack of solid preparation for the case so in the decision gallup vs cheney ten one twenty five twelve forty one c v the decision indeed in attempting to marshal a series of unsubstantiated and inconsistent allegations inconsistent allegations note that in order to explain why american airlines flight seventy seven did not crash into the pentagon the complaint utterly fails to set forth a consistent much less plausible theory for what actually happened that morning in arlington virginia we just saw there was no way the plane the april gallop could have gone through and come out the conspiracy among the defendant although like the district court we do not reach the question of whether judicial stoppel bars gallops complaint we note that in the complaint it's factually a direct reconcilable with factual allegations made by gallup other actions so in other actions she said that she's the plane had impacted it and now she's saying there isn't but there's been no evidence presented in this case as to why she changed her opinion i was actually in the courtroom when bill veal was defending himself in the founding a full gallop and in front of the three judges in new haven connecticut based court house and when he was asked the question didn't she make these other  substantiated assertions that a plane did hit the pentagon in the past he looked like he had been kicked in the stomach he just that was just the end of the game i was just floored i expected a much better  response but in fact the case was ultimately dismissed and later i find out that it was based on basically nothing october thirty first april gallop is interviewed by the center for military history the interviewer asked and we're going to go through this because it's it's kind of an important piece of the april gallop story and this is what she said weeks afterwards you know you were what happened that day april i talked to my first sergeant before she went to our meeting to let her know that i received my letter from my director i sat down at the computer at one echo five seventeen and as soon as i was about to turn the computer on boom ok there was such a great impact at the moment i didn't even get to turn the computer on you know the computer blew and everything changed it went from light pleasant environment to just total dismal darkness flame and fire happened that fast there was no you know slow motion about it it just happened so fast you know when it hit it was like everything crumbled walls that computer blew fire it all happened in your sleep and i wasn't covered all the way i was just covered from my waist down so i was able to like move around to see what was and what the world happened black but you could see things in the fire that was in the back you were able to see certain things you know by the light of the fire because of the flame but it was dark in there smoke you know a lot of smoke in the flames weren't so big in you when i'm unable to really see very much except like right in front of you i took a deep breath first because i was like whoa what happened so fast to go from a room that was like to something like that you have to pinch yourself and say oh my god is bill and then i had my son was mean so my newborn maybe was with me and so i was trying to maintain myself so i would not freak out he was right next to me in a stroller at first i didn't think he was ok because his stroller got caught on fire so i thought when he was crying it was crying because he was burning that's what i thought you know it's it's first had to get myself together emotionally before i thought about ok what's my next because i can't believe this happened my son my son you know but i calmed down and i was just thinking ok i need to do something you know i see over there on that  side that there's a stroller and i'm like my god that's why he's crying he was next to me he was blown he was blown it was like when the impact hit the stroller was blown in one area and when i did finally find him he was farther from the stroller bre but i thought he was in the stroller first and then when i turned to look back i could see people from the ceiling and i could see people i could hear people a lady and fire i could see different things when i looked to the back i crawled out got the stuff off from under me and i crawled out and i went to that stroller that was the first thing because i thought he was crying because in the stroller he was in there and i was like oh my god where is my son eventually find him find my son in the debris he's in a ball like that but when i picked him up he was laid out like that so i was thinking oh my god his bones are broken i was just thinking so many things crying like oh my god a camp and that's when we heard so and so i was blacked out well i didn't know exactly who it was at that particular time but it was a male and female saying where are you all at we found a way out you could hear them talking but i could hear bits and pieces because i thought for sure we were going to get burned up next because even though we were free from the debris we didn't it they made a little groove for a little way and we got over it and from someone so explain to me they found a way further out so they helped us get out of our trapped area and then they helped us get the way out after that they said i passed out because i was just so glad to be out of there you know i passed out with my baby is that somebody help somebody had my baby i don't remember from the time we actually got right outside the building i just remember coming to the hospital wondering where is my son is the first thing i could think of so that's april gallops story as told a center for military intelligence cruise cortez  tells the story of april gal's baby on the first floor of the earring in the darkness after the crash crew's courtis awoke to the sound of a baby crying a wall had collapsed pinning her elder desk she her coworkers had been knocked unconscious her colleagues her colleague specialist april gallop thirty had brought her two month old son eliza's to the office so that she could roll in at the pentagon daycare center gallop also trap regain consciousness our baby stroller on fire but election had been thrown clear in the room smoke filled back mistress cortez sensed fire raging beyond the wall that it collapsed onto or another coworker army corporal eduardo bruna pardo twenty helped free or they helped gallup find her baby who was not badly injured these enlisted clerks and ministry of assistants and that were not the kind of people who get window offices at the pentagon so they were in interior office on the earring searching for a way out through the smoke and dust everyone come toward me cruise cortez heard from the partner yell he had found a blown out window in a demolished office across from what was left of the hall about a hundred people gathered at the window about ten people gathered at the window and the end jumping down it was a seven foot drop sergeant christopher he recounts in this december first two thousand and one as he ran towards the sun the source the first victim me encountered was a lady staggering away with a baby in her arms i grabbed the baby and i realized the back of the baby's head was charred so i ran to look for medical help he recalled he headed off the child to someone outside and returned to the building area burning area with who turned out lieutenant colonel paul anderson who was who a sergeant  before the two entered said dear lord give me the strength and we went in so this diagram here shows probably the way that they got out was to go through a  window probably about three and maybe five and north this is about behind where the fire truck would have been located and the use of the the window  areas it's not clear which one of these that she would have gone out but they would have had about a seven foot drop blast resistant windows on the right hand side of the doorway that's when one in the once two was on the the left side and you can see  the difference in the way that the windows responded to the destruction up talk a little bit about ground effect in this section we're going to be observing some extend behind in airborne aircraft as shown in the image high pressure air under the wings creates a downwash and then this higher pressure moves both downward and outward and then upward and as it does that it creates a rotation  shown in by the columns it takes energy to create these border cities and so energy is absorbed from the from the system from the plane moving by from the engines to create peace of war to seize and it has to be absorbed out of the engines through thrust you can see these as the planes fly through clouds sometimes and there's some pretty remarkable pictures of them here's one here's a test that was done with a crop duster going through a very colorful set of smoke and you can see that when to board sees as a as it passes close to the ground here's an example of the wing tip morrissey's at some significant distance and you'll see that it's going to create this this circular energy we actually saw one of these in a previous slide something similar to this had there been a fly over a bed of the pentagon and there there would have been some evidence of it that you would have seen some air motion as the air would have gone up and around as  ground effect some assert that a plane could not get low enough to hit the first floor due to ground effect the ground effect doesn't prevent planes from approaching the ground typically ground effect increases the air speed to create the wing tip or to seize energy is expended from the jets and from the engines more power from the engine thrust is then available once you get closer to the ground in wing tip foresees are reduced the energy to create them is reduced increasing lift in this picture here what we see is a wing to what it sees being created on the left hand side more than half of wingspan above the ground on the right hand side closer to the ground you can see the are being compressed and so it takes a little bit less energy to increase them and also to create them and it also increases the effective wing surface area when you getting close to the ground this additional turbulence might take up things like grass clippings and other dust things that would have been what penny had was saw in her prior quote the ground effect begins about a half wingspan above the ground the plane approaching the pentagon however was more than a half wing span above the ground for much of its approach until about the final two thousand seater about two and a half seconds adjusting control surface can compensate for the slight nose down attitude counter act the effect of the ground ground effect and the plane approaching the pentagon did have this downward trajectory so it's quite likely that ground effect was overcome by the plane's orientation however this does speak to a question about what a novice pilot be able to be able to do this and other little evidence from other pilots that have attempted to do this in flight simulators it is taking them many times to actually get it right to be able  hit the pentagon at an appropriate location here's a topography map showing the route that we were looking at and showing that the plane is above half a wing it was a controlled impact demonstration designed to underscore the results of exhaustive research into specific areas of aircraft safety improved cross protection and reduced post crash fire hazard the crash of that objectives were to obtain data on the impact forces transmission of forces through the structure to the seats in the occupants evaluate energy observing seats compare predictive structural behavior with an actual crash and a test ground effect did not prevent the plane from approaching the ground wing flaps were down which increases ground effect still then save every save the plane from hitting the ground slower speed increase of the ground effect the plane descended smoothly below half wingspan slid on the underside of the plane upon hitting the ground significant you are rotation begins immediately when the left wing touches the ground so when we talk about  of the plane was hit the diesel generator here are going to see the impact of a less pronounced wing touching the ground in forcing the plane to rotate or or to ya so here is a picture of the shelling all approach above a flat flat surface plane altitudes about a half a wingspan above the flat surface now plane is less than a half wingspan above the flat surface and it's not getting popped up it doesn't push the port wing up to level the pla ground effect were a strong force that becomes exponentially greater as the wing approaches the ground and as some suggest the port wing should not be able to drop lower than the starboard wing absence a large force from the control surfaces if the ground effect were such a strong sector closer to the earth the forces of the left wing would be so large in the upward direction under the left wing that you know the earth would be impossible and would self correct the plane to be flat level but the ground effect doesn't do that it doesn't keep the plane level and now what you see is one of the engines is starting to drag on the ground doesn't hit anything solid like a diesel generator trailer and what the planes actually rotate so i'll take a look at that gar a little bit more will mark the points in the in the study frame here where the tail as you can see is moving and moving moving moving moving moving and so the low tail location of the tail markers showing rotation to the wing impact and as you move from points one two and three the plane is not significantly rotating between four and six takes point three eight seconds the left wing slides on the ground again and then encounter a large a movable object and the engine on the opposite side was not at full power