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9/11 on Google Earth

Thanks for all the feedback.

Gumboot, what do you mean by wrong direction? Is the plane pointing backwards, or is it just slightly turned off of the direction of flight? If it's just slightly turned, that might be the drift (and/or yaw). There are some points in flight, particularly just after take off, when the plane drifts by almost 10°. It appears there was quite a wind upthere. If you popup a balloon for the particular position, there are three headings.

Track angle is actual flight direction. At least I think it should be. And it should comply with the flight path below. True heading is the direction, the plane's nose is, or should be, pointing at. Those are not neccessary the same, because of wind and/or rudder action by the pilot. The third heading is magnetic, but that's not used anywhere and it doesn't affect the position of plane models.

Pitch/Roll seem OK to me, but I do have to say I haven't been able to check each and every model up close. Is the roll wrong during the whole turn? Post some screenshots. Here's a few of my own.



Can you be more specific which models appear weird?

Apathoid, yes there is also radar alt, but I wanted to present the complete flight paths first. Rad alt works only to about 2500 ft, but I'm sure I don't have to tell you this. I've been following your and Anti-Sophist's posts and learned a lot. You guys put it more eloquently and precisely than I ever could and the terminology used is still a bit above my attention span :) That's why I can't explain why I think the Lat/Long data is only accurate to 1NM in precise language. Beachnut, has also posted some useful info. Well, at least when I was able to vaguely understand what he was talking about ;)

Sorry, Beachnut, I'm unable to parse your post above. Is it supposed to be a rant/critique of PfT in general or is it a critique of my presentation?

Gravy, you don't have Google Earth or does it fail to load? Or did the HQ get you stuck with a decade old, hand me down computer from our globalist depository? Well, that's for being a field operative. Should've had joined the Office Corps when you had a chance. Sure, counting socks is a bit tedious at times, but we get computers which are hardly 3 years old!

About "playing" the file. Animation, by flying behind the plane, is on my mind, I just have to come up with right trigonometry to adjust the view of each particular point. I'm not there yet. If you just want to play a particular section of the flight path, you'll have to copy or move those points, one by one, into some other folder and play them there.
 
celestrin said:
Thanks for all the feedback.

Gumboot, what do you mean by wrong direction? Is the plane pointing backwards, or is it just slightly turned off of the direction of flight? If it's just slightly turned, that might be the drift (and/or yaw). There are some points in flight, particularly just after take off, when the plane drifts by almost 10°. It appears there was quite a wind upthere. If you popup a balloon for the particular position, there are three headings.
Click to expand...



It's obviously something wrong with my display, because the aircraft has an incorrect roll position for the entire turn...

Here's a screen cap:



This second picture shows what I mean about the pitch angle...

This is the final descent towards The Pentagon...

According to the FDR the aircraft was pushed into full throttle, so there's now way it would have continued to descend in a nose-up attitude like this.



But it appears the bug is that for some reason my Google Earth is displaying it backwards.

-Gumboot

ETA...

Heh, okay well I think this settles it... for some reason it's displaying it backwards for me...

That is, unless the below picture is a standard American Airlines departure profile...



Heh.
 
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celestrin said:
Apathoid, yes there is also radar alt, but I wanted to present the complete flight paths first. Rad alt works only to about 2500 ft, but I'm sure I don't have to tell you this.
Click to expand...


Yup, I was just suggesting that perhaps it could be used for the final portion of the flight, for the sake of accuracy - especially with PfT espousing their theory that the plane was "too high!!" and I just thought that radalt data might've been easier to deal with.

That's why I can't explain why I think the Lat/Long data is only accurate to 1NM in precise language.
Click to expand...


Technically, it should be accurate to 0.1 NM, which is the resolution of the DME data that the FMS uses to update the lat/long. But as I mentioned above, there is an inherent error introduced when the position is input and the FMS will indeed accept positions that are a mile off both in lat and long. Only until a valid VOR/DME is tuned, will the FMS start updating and correcting the lat/long. It may sound kind of silly that the FMS needs to correct the errors that it previously allows, but the reason the lat/long updates isn't because it has to correct the entry error; it's to correct inertial drift, which can be as much as 3 NM/hour
 
Well ,those do look weird, Gumboot. Can you put time tags to them? Especially the departing one. And what GEarth version are you using?

Yeah, thanks, Apathoid. About short range DME accuracy. I know, well, I've read it somewhere, that DME accuracy is generally up to 0.1NM, but I can imagine that the accuracy would drop as you get closer to the repeater. Is there any idea how accurate DME is 1.5NM from the repeater?
 
celestrin said:
Well ,those do look weird, Gumboot. Can you put time tags to them? Especially the departing one. And what GEarth version are you using?
Click to expand...


I'm a bit of a Google Earth virgin so you will have to talk me through this "time tag" thing...

I only downloaded Google Earth an hour or two ago, so I'm assuming it's the newest version.

-Gumboot

ETA. the time for that departure one is 08:20:30. It's the first aircraft model once the flight is airbourne (the previous one the aircraft is still on the runway)
 
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Thanks. I get this.


Could you just copy the following code to clipboard and paste it in GE's list view? You get a placemark. Doubleclick it to adjust the view and save a screencap, please.
Code: 
<?xml version="1.0" encoding="UTF-8"?>
<kml xmlns="http://earth.google.com/kml/2.1">
<Document>
	<name>KmlFile</name>
	<StyleMap id="m_ylw-pushpin_copy0">
		<Pair>
			<key>normal</key>
			<styleUrl>#s_ylw-pushpin_copy0</styleUrl>
		</Pair>
		<Pair>
			<key>highlight</key>
			<styleUrl>#s_ylw-pushpin_hl_copy0</styleUrl>
		</Pair>
	</StyleMap>
	<Style id="s_ylw-pushpin_copy0">
		<IconStyle>
			<scale>1.1</scale>
			<Icon>
				<href>http://maps.google.com/mapfiles/kml/pushpin/ylw-pushpin.png</href>
			</Icon>
			<hotSpot x="20" y="2" xunits="pixels" yunits="pixels"/>
		</IconStyle>
	</Style>
	<Style id="s_ylw-pushpin_hl_copy0">
		<IconStyle>
			<scale>1.3</scale>
			<Icon>
				<href>http://maps.google.com/mapfiles/kml/pushpin/ylw-pushpin.png</href>
			</Icon>
			<hotSpot x="20" y="2" xunits="pixels" yunits="pixels"/>
		</IconStyle>
	</Style>
	<Placemark>
		<name>screenshot</name>
		<LookAt>
			<longitude>-77.13406285962059</longitude>
			<latitude>38.76918047776447</latitude>
			<altitude>0</altitude>
			<range>4398.415556215872</range>
			<tilt>67.00602126382916</tilt>
			<heading>-95.77250840991209</heading>
		</LookAt>
		<styleUrl>#m_ylw-pushpin_copy0</styleUrl>
		<Point>
			<coordinates>-77.14527332482233,38.76748511673036,0</coordinates>
		</Point>
	</Placemark>
</Document>
</kml>
Here's what I get.

ETA: You can save jpegs in GE by going to File->Save->Save Image
 
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celestrin said:
Yeah, thanks, Apathoid. About short range DME accuracy. I know, well, I've read it somewhere, that DME accuracy is generally up to 0.1NM, but I can imagine that the accuracy would drop as you get closer to the repeater. Is there any idea how accurate DME is 1.5NM from the repeater?
Click to expand...

I think you may be referring to slant range. Since DME measures line-of-sight range to the DME station, if you overfly the station at altitude - the distance will indeed be off from the very same position on the ground(ie if you directly overfly the station at 35,000 ft, the DME range won't drop below about 6 NM).

In the case of flight 77, the aircraft was so low at that point that the slant range and actual range were only like 10 feet different!

"Inside the box", there is nothing that would make the system less accurate closer to the station. The DME interrogates the ground station something 100x a second and the reply is only delayed by a few microseconds, which is actually compensated for in the DME.
 
Interestingly enough, if you look at the FDR flight track (assuming it is accurate) the final position is 1,411 metres from the Citgo station, and the projected heading will carry the aircraft to the south.

Travelling at 460kt (ignoring the fact it's accelerating for now) the aircraft will reach the Citgo in 5.1 seconds. At the final position it also has a 3.5o roll to starboard which has increased from a port roll in the previous 3 seconds, which means it's only the beginning of the input.

So in 5.1 seconds the aircraft has to reverse it's current roll, and roll back the other way enough to shift it's lateral position by about 200-250 metres.

Is that enough data to calculate the G-force such a maneouver would produce?

The aircraft then has 520m (2.1 seconds) to correct back the other way even FURTHER to ensure the aircraft passes The Pentagon at the point where the explosion occurs.

-Gumboot

-Gumboot
 
Sorry to spam the thread with my repeated posts...

I wonder if a similar model could be presented for UA93? It would be interesting to see.

-Gumboot
 
apathoid said:
I think you may be referring to slant range. Since DME measures line-of-sight range to the DME station, if you overfly the station at altitude - the distance will indeed be off from the very same position on the ground(ie if you directly overfly the station at 35,000 ft, the DME range won't drop below about 6 NM).

In the case of flight 77, the aircraft was so low at that point that the slant range and actual range were only like 10 feet different!

"Inside the box", there is nothing that would make the system less accurate closer to the station. The DME interrogates the ground station something 100x a second and the reply is only delayed by a few microseconds, which is actually compensated for in the DME.
Click to expand...
Ok. Makes sense, thanks. I'll stick to .1 then.
 
I am kind of new to Google earth but managed to get it to run.

Wow, just wow, well done to all concerned.


 
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