The Second Hit Plane Did Not Slow At All Upon Impact

If you look at the footage Webfairy has broken down here, you can see how the plane moves frame by frame.

The plane takes ten frames to enter the building.

Webfairy explains here how she formatted the videos, and says the videos were taken at 30 frames per second. This is consistent with other sources on the frame rate of video.

Okay, so we know the length of a 767 is 160 feet.

This means it takes 1 second to show 480 feet traveled by the plane (160 times 3 = 30 frames per second). So the plane is traveling 480 feet per second, which works out to 28,800 feet per minute and 5.45 miles per minute, which works out to 327 mile per hour-- AS IT ENTERS THE BUILDING.

So how fast was the plane moving before it entered the building?

The top left clip here shows the plane moving before it hits the building. Since the plane is moving against a column of smoke, we can use this as reference and see that the camera is not moving significantly.

Before it hits the building, the plane takes 12 frames to cross its own length, or 160 feet.

This means it takes 1 second to show 400 feet traveled by the plane (30 frames per second divided by 12 frames = 2.5/sec; 160 times 2.5/sec = 400 feet/sec). So the plane is traveling 400 feet per second, which works out to 24,000 feet per minute and 4.5 miles per minute, which works out to 272 miles per hour-- BEFORE IT ENTERS THE BUILDING.


Right before the impact, the plane takes about 12 frames to cross its length, though this is trickier to measure as the camera is moving. Nonehteless, it seems extremely unlikely in the few seconds before the plane hits that it accelerated significantly -- so we can assume the plane did not slow upon impact. If anything the plane accelerated upon impact, but this may be due to the limitation in these types of measurements. What is clear, however, is that the plane does NOT SLOW UPON IMPACT.

HOW CAN THIS BE?

CONCLUSION: Either--

1) the plane met no resistance upon impacting the steel building (which is impossible)

2) the plane disintegrated sequentially as it entered the wall, and this disintegration had no effect on the non-disintegrated part of the plane (which seems impossible)

3) the plane was not real, it was a digital image inserted in the footage of the building exploding.

Anyone want to pick a choice?


p.s. Oddly, the speed of the second hit varies widely from video clip to video clip. The official speed was almost 600 mph, but I don't believe this. I think it was probably going a more reasonable 300 mph-- although if the plane only existed on a computer, it is not clear how meaningful this is!

Update: One other point One other point, which I forgot to put in the post is that if you measure the lengths of plane per frame as it goes in, it is fairly even. Thus the speed does not even appear to change as the plane enters the building. So,
even if you make the unlikely assumption the pilot accelerated maximally exactly as he hit (which given the turn he was supposedly making is really difficult I think), it is not like the plane goes in faster and then slows down as it goes in, giving an overall average speed that is the same as the pre-impact speed.

FINAL CONCLUSION: the plane does not slow upon or during the impact.