Yup, had those ideas years ago when the Citizen In Treefort still seemed to be worth spending my time on.
http://www.randi.org/forumlive/showpost.php?p=2121297&postcount=1211
Darth and Reheat probably don't realize that the Skyline Mall is a part of a larger building complex in Bailey's Crossing, comprised of
One Skyline Tower, a 365ft tall building (4th tallest in DC/Arlington area), and a bunch of other tall buildings in excess of 20 stories high.
http://maps.google.com/maps?hl=en&tab=wl&q=One Skyline Tower
Look at how the Pentagon leaps out of this picture. The many "large buildings" are not so notable. Pentagon is bloody huge. It's a great visual landmark.
By the way, are you referring to Bailey's Crossroads? On Route 7?

About four miles south west of the Pentagon? Memories ...
I even suspected that the VFR might be responsible for that "S" manuever they did to the south of Dulles, just as they'd switched off the autopilot for the last time and started the initial descent from 8100 to 6900ft. You see, the plane turned towards the Tysons Corner for a minute or two. Tysons Corner also has some highrises and has a similar relative position to one of the bends in the Potomac as the Skyline does. But, as said, this is mere speculation on my part...
From 400', sure, a possibly easily identified and thus significant terrain feature. Tyson's Corner, also
huge mall complex (first time I went there was in 1972) is, while spread out, not as clear a landmark as the Pentagon. Also, the road junction it abuts, 123/Rte 7, is a better visual landmark from the air than a given tall building unless the building stands well away from other buildings. I invite you to go to the satellite version of the linked map and play with the resolution/scale a bit. Zoom in and out. Move from Pentagon to Tyson's Corner on the same mag and see how much clearer the Pentagon is than the various buildings in the shopping center. Then do the same for Bailey's Crossroads.
From 5-10,000 feet, your tall building might not be so easy to pick out the first time you are looking for it.
Pentagon? A snap. The key is in using lateral references to "point" to your chosen landmark, which makes the Potomac a dead cinch for a guiding landmark, considering altitudes we are discussing for Hanjour.
What looks like a tall building to you on the ground may not
look as tall from the air. The spread of it, width, on the ground also adds to or subtracts from ease of identification from the air. Unique color or reflective quality may make a building stand out.
As Reheat pointed out, the combination of building clusters and road networks tend to be used together to identify and confirm visual checkpoints when flying over densely developed terrain.
Hanjour had now many flights over the DC area? If none, he's got the problem of matching the road/building patterns he sees with what he expects to see.
Depending on his prep work, maybe easier or more difficult depending on the imagery he had to hand.
Now, with Google earth, much easier than then.
What the hell do I know? Only taught VNAV for two years.
Pentagon as alternative target: alternative to what?
senenmut said:
well, there was nothing stopping him going straight down into the pentagon either without the loop.
For the love of Pete, please stop. Really. A loop?
*slams head on desk*
The word does not mean what you think it means.
A loop is a vertical maneuver in an airplane. There is no data to support the aircraft doing a loop. Hanjour wasn't that stupid. Any guesses as who might be?
DR