My husband, may G*d give him rest, worked on the flight line when he was in the service, so I know something about airplanes. Here is what I know, form reading his books and hanging out with the guys who worked with my husband and what I learned from reading the after action reports on the Twins (WTC)

First let us consider what Professor Alastair Soane said about the WTC and if they were as you think built to withstand an airplane strike: "They were extremely robust buildings and built to withstand a tremendous amount.
A large cannon shooting blanks.

"But this was of course a completely abnormal situation and one which would not have been envisaged by the people who built it. (the plans for the WTC was drawn up in the 50s). The strength of the towers was enormous but they would not have been designed for aircraft strikes.

"There are buildings which are designed to withstand plane impacts but these are mainly for very sensitive buildings. The main impact on a building would be from the engines because they hold the mass of the plane, but there is also the fuel which would ignite.

Now for the building, the spandrels that made up the outer frame of the WTC at the 70-90 floor range were made up of 3/8" steel with a 14" box beam behind the fascia steel (clad in aluminum) also made up of 3/8" steel. In between the spandrels was approximately 26 inches of tempered glass. These spandrels were connected by four (4) bolts and light welding. See, FEMA’s WTC Steel Data Collection, page D-5.

The aircraft wings and center fuel tank of a 767 holds approximately 23,980 gallons of jet fuel. It is estimated that only 10,000 gallons was on board, with the aircraft taking off with only a partial load of fuel (only what it needed for its transcontinental flight plus the required FAA/Delta-mandated reserve)and burning a fixed amount on its flight. 10,000 gallons weighs about 60,000 lbs (Jet fuel weighs about 6.84 lbs per gallon). Now then, 30 tons of fuel spread between two wings, or about 1,500 gallons per wing would equal to about 9,000 pounds per wing.... about 4.5 tons in each wing. And then the center fuel tank with about 20 tons of fuel. http://simviation.com//rinfo75767.htm
http://www.streamline-ops.com/en/info/fuel_weight_conversion_tables/

Moving on to the aircraft itself, there is another estimated 25-30 tons of dense, heavy metal included in the construction of these jets, from titanium to steel to solid aluminum making up elements such as the wing spar support infrastructure. http://www.boeing.com/history/products/767.page
http://www.boeing.com/commercial/airports/plan_manuals.page

Now then for the CT, the airplane should have "bounced" off the WTC or exploded on the outside of the building.

The aircraft, see above references is 155 feel long, and at the time of impact weighed close to 100 tons..... with four tons of fuel in the wings and another 20 tons at center. It was traveling at cruising speed, 493 knots = 567.334 267 876 mile/hour (mph) official max cruising speed... which is the speed necessary to maneuver without stalling.... how is it that the CT thinks it should have crumpled up when hitting 3/8 inch steel and tempered glass?

And what was the catalyst to cause it to explode outside of the building. http://www.aircrash.org/burnelli/ht960724.htm
"Modern jet fuel has a much higher flame point and vapour pressure than does regular gasoline as a result. Fuel tanks are fitted with baffles and sometimes coolers to keep the fuel liquid so it doesn't explode easily. This is in part a result of what happened to TWA800, one of the very few accidents to be caused by a fuel tank explosion (and there the explosion was itself only possible due to a combination of rare circumstances and chance events, made worse by maintenance problems with the aircraft).
The image of aircraft (and cars, trains, ships, buildings, anything really) blowing up in a wall of flame at the least trouble is one created and perpetuated by Hollywood and has no reflection in reality whatsoever." "The NIST investigation revealed that plane debris sliced through the utility shafts at the North Tower's core, creating a conduit for burning jet fuel—and fiery destruction throughout the building. "It's very hard to document where the fuel went," says Forman Williams, a NIST adviser and a combustion expert, "but if it's atomized and combustible and gets to an ignition source, it'll go off."

Burning fuel traveling down the elevator shafts would have disrupted the elevator systems and caused extensive damage to the lobbies. NIST heard first-person testimony that "some elevators slammed right down" to the ground floor. "The doors cracked open on the lobby floor and flames came out and people died," says James Quintiere, an engineering professor at the University of Maryland and a NIST adviser. A similar observation was made in the French documentary "9/11," by Jules and Gedeon Naudet. As Jules Naudet entered the North Tower lobby, minutes after the first aircraft struck, he saw victims on fire, a scene he found too horrific to film." "Jet fuel burns at 800° to 1500°F, not hot enough to melt steel (2750°F). However, experts agree that for the towers to collapse, their steel frames didn't need to melt, they just had to lose some of their structural strength—and that required exposure to much less heat. "I have never seen melted steel in a building fire," says retired New York deputy fire chief Vincent Dunn, author of The Collapse Of Burning Buildings: A Guide To Fireground Safety. "But I've seen a lot of twisted, warped, bent and sagging steel. What happens is that the steel tries to expand at both ends, but when it can no longer expand, it sags and the surrounding concrete cracks."

http://aviation.stackexchange.com/questions/1809/is-it-possible-to-prevent-plane-accidents-due-to-fuel-explosion
http://www.popularmechanics.com/military/a6384/debunking-911-myths-world-trade-center/

Okay...so an airplane is thicker than what you report.
The WTC was designed in the 1950s and was not designed to withstand the crash of a plane built in the 1990s.
It was not the crash that took down the building, it was the burning fuel traveling down the elevators shafts that weakened the building core....

My husband, may G*d give him rest, worked on the flight line when he was in the service, so I know something about airplanes. Here is what I know, form reading his books and hanging out with the guys who worked with my husband and what I learned from reading the after action reports on the Twins (WTC)

First let us consider what Professor Alastair Soane said about the WTC and if they were as you think built to withstand an airplane strike: "They were extremely robust buildings and built to withstand a tremendous amount.
A large cannon shooting blanks.

"But this was of course a completely abnormal situation and one which would not have been envisaged by the people who built it. (the plans for the WTC was drawn up in the 50s). The strength of the towers was enormous but they would not have been designed for aircraft strikes.

"There are buildings which are designed to withstand plane impacts but these are mainly for very sensitive buildings. The main impact on a building would be from the engines because they hold the mass of the plane, but there is also the fuel which would ignite.

Now for the building, the spandrels that made up the outer frame of the WTC at the 70-90 floor range were made up of 3/8" steel with a 14" box beam behind the fascia steel (clad in aluminum) also made up of 3/8" steel. In between the spandrels was approximately 26 inches of tempered glass. These spandrels were connected by four (4) bolts and light welding. See, FEMA’s WTC Steel Data Collection, page D-5.

The aircraft wings and center fuel tank of a 767 holds approximately 23,980 gallons of jet fuel. It is estimated that only 10,000 gallons was on board, with the aircraft taking off with only a partial load of fuel (only what it needed for its transcontinental flight plus the required FAA/Delta-mandated reserve)and burning a fixed amount on its flight. 10,000 gallons weighs about 60,000 lbs (Jet fuel weighs about 6.84 lbs per gallon). Now then, 30 tons of fuel spread between two wings, or about 1,500 gallons per wing would equal to about 9,000 pounds per wing.... about 4.5 tons in each wing. And then the center fuel tank with about 20 tons of fuel. http://simviation.com//rinfo75767.htm
http://www.streamline-ops.com/en/info/fuel_weight_conversion_tables/

Moving on to the aircraft itself, there is another estimated 25-30 tons of dense, heavy metal included in the construction of these jets, from titanium to steel to solid aluminum making up elements such as the wing spar support infrastructure. http://www.boeing.com/history/products/767.page
http://www.boeing.com/commercial/airports/plan_manuals.page

Now then for the CT, the airplane should have "bounced" off the WTC or exploded on the outside of the building.

The aircraft, see above references is 155 feel long, and at the time of impact weighed close to 100 tons..... with four tons of fuel in the wings and another 20 tons at center. It was traveling at cruising speed, 493 knots = 567.334 267 876 mile/hour (mph) official max cruising speed... which is the speed necessary to maneuver without stalling.... how is it that the CT thinks it should have crumpled up when hitting 3/8 inch steel and tempered glass?

And what was the catalyst to cause it to explode outside of the building. http://www.aircrash.org/burnelli/ht960724.htm
"Modern jet fuel has a much higher flame point and vapour pressure than does regular gasoline as a result. Fuel tanks are fitted with baffles and sometimes coolers to keep the fuel liquid so it doesn't explode easily. This is in part a result of what happened to TWA800, one of the very few accidents to be caused by a fuel tank explosion (and there the explosion was itself only possible due to a combination of rare circumstances and chance events, made worse by maintenance problems with the aircraft).
The image of aircraft (and cars, trains, ships, buildings, anything really) blowing up in a wall of flame at the least trouble is one created and perpetuated by Hollywood and has no reflection in reality whatsoever." "The NIST investigation revealed that plane debris sliced through the utility shafts at the North Tower's core, creating a conduit for burning jet fuel—and fiery destruction throughout the building. "It's very hard to document where the fuel went," says Forman Williams, a NIST adviser and a combustion expert, "but if it's atomized and combustible and gets to an ignition source, it'll go off."

Burning fuel traveling down the elevator shafts would have disrupted the elevator systems and caused extensive damage to the lobbies. NIST heard first-person testimony that "some elevators slammed right down" to the ground floor. "The doors cracked open on the lobby floor and flames came out and people died," says James Quintiere, an engineering professor at the University of Maryland and a NIST adviser. A similar observation was made in the French documentary "9/11," by Jules and Gedeon Naudet. As Jules Naudet entered the North Tower lobby, minutes after the first aircraft struck, he saw victims on fire, a scene he found too horrific to film." "Jet fuel burns at 800° to 1500°F, not hot enough to melt steel (2750°F). However, experts agree that for the towers to collapse, their steel frames didn't need to melt, they just had to lose some of their structural strength—and that required exposure to much less heat. "I have never seen melted steel in a building fire," says retired New York deputy fire chief Vincent Dunn, author of The Collapse Of Burning Buildings: A Guide To Fireground Safety. "But I've seen a lot of twisted, warped, bent and sagging steel. What happens is that the steel tries to expand at both ends, but when it can no longer expand, it sags and the surrounding concrete cracks."

http://aviation.stackexchange.com/questions/1809/is-it-possible-to-prevent-plane-accidents-due-to-fuel-explosion
http://www.popularmechanics.com/military/a6384/debunking-911-myths-world-trade-center/

Okay...so an airplane is thicker than what you report.
The WTC was designed in the 1950s and was not designed to withstand the crash of a plane built in the 1990s.
It was not the crash that took down the building, it was the burning fuel traveling down the elevators shafts that weakened the building core....

PL "I am willing to entertain that idea... so, how does it work? How did they get it into the buildings....as I would imagine that they would have to plant it in all the buildings. How much would they need....and how did they set it off?"
That is why 2'200 A & E's signed a petition for a legitimate investigation. Building 7, the third WTC building to collapse, wasn't even mentioned in the official report.

Everything all Americans should know about 911 in under 5 minutes
http://www.youtube.com/watch?feature=player_embedded&v=A_IZaUuK_d0
Exposing the fraud of 9/11 in 22 minutes
http://youtu.be/afUS_58XC5I

Firefighter Exposes Conspiracy
http://youtu.be/RR2VefBj-_U


Compiled footage of Building 7 collapse:
http://www.youtube.com/watch?feature=player_embedded&v=p34XrI2Fm6I
http://www.youtube.com/watch?v=bWorDrTC0Qg
http://www.youtube.com/watch?feature=player_embedded&v=nQrpLp-X0ws
The 911 False Flag will not be swept under the rug.
Rebecca Roth, a former stewardess, has researched 9/11 more exhaustively than most of us. She has more insight into airline procedures and equipment than most. In this video she explains many of the connections of people and corporations which were involved in the attacks This is a bombshell of information: http://www.youtube.com/watch?v=qdP95oSoOFk