Question for those familiar with flying.

[Hoping4Change]

Are there mechanical reasons why the person piloting Flight 77 didn't just do a gradual dive into the Pentagon? Why the complicated manouvring?

[JeffR]

1. Graduate of the Magic Bullet Aviation School

It's just the way they teach it there.

[Ian David]

2. How do you think the airlines loses your luggage? n/t

[TomInTib]

3. If I was flying the plane, I would go for max penetration.

They came in high on the first pass and had to pull a descending spiral to come in low and flat.

That feat is right up there with Oswald getting off all those shots in mere seconds with a piece of crap rifle and making them all count.

[petgoat]

4. I'd guess it was evasive action. I believe it flew over the White

House at 7000 feet, then pulled a diving 270 degree turn. John Judge said he was told by a
Pentagon security guy that they had SAM missiles there. The White House had SAM missiles, the
G-8 conference at Genoa in 7/01 had SAM missiles, and W had SAM missiles at his hotel at Longboat
Key in FL the night before 9/11. So prudent hijackers would have avoided telegraphing their
course.

[truebrit71]

7. But..why would they have SAMS if no-one thought they would use...

...planes as weapons?

Hmmmmmmm?

[petgoat]

10. The "Atlanta Rules" at the '96 Olympics closed the airspace.

Al Qaeda's Project Bojinka plan to fly hijacked airliners into Sears Tower, WTC, and the Pentagon
were known in 1995.

[benEzra]

14. I think SAMs were installed after that nutjob tried to fly a Cessna

into the White House during President Clinton's first term. They're just shoulder-fired missiles, not something that could stop an airliner from straight ahead.

[petgoat]

17. Right you are; they were Stingers at the White House.

Even so, given that the WH was defended from aerial assault, is it reasonable to
think the Pentagon was not?

[benEzra]

18. Be surprising if it weren't...

though if the Pentagon were as complacent about the AQ threat as the FBI seems to have been, I wouldn't be particularly surprised.

Shoulder fired missles won't do anything about an airliner coming straight at you at 500 knots, though. Could be they were there (for defense against small-and-slow threats) and couldn't be put into action in time. The final approach would have been low, incredibly fast, and straight in, with the plane almost keeping up with the sound of its engines.

[Hoping4Change]

11. Do you know if the missiles manned 24-7?

If so wouldn't those manning the missiles at the Pentagon on 9-11 be alarmed at the sharp turn a commerial jet was making overhead. Wouldn't all overhead air traffic be monitored?

[Old and In the Way]

26. If it flew over the WH and continued on over RR Airport, the

turn is closer to 200 degrees to orient properly to the Pentagon Wall. In which case, this was one heckuva of a flying feat.

[Sammy Pepys]

5. Not that it would too hard to do it, but....

...if you're talking about someone who is probably not intimately familiar with the feel of a large commerical jet like that, it's very likely they'll not be able to steer it very precisely...not to mention dealing with weather, nerves, etc.

[Hoping4Change]

13. Actually the air traffic controllers thought it was a military craft

because it was an extremely difficult manouvre.

[bmcatt]

23. ATC could only do this if the transponder was on

This finally turned into a concrete thought for me... On the one hand, we have the presumption (I think) that the hijackers turned off the transponders which is why ATC wasn't exactly sure where they were.

If the transponders were off, how exactly could ATC tell that the aircraft (note I don't say "airplane", but I don't imply anything else...) did a *descending* turn? Without mode C reports (altimeter readings for anyone who's not a pilot), ATC would have absolutely no altitude indication.

Alternatively, if the transponder was off at some point, but on for the attack on the pentagon, did the hijackers turn it back on so that ATC could see what a cool maneuver they were doing? The terrorist equivalent of a frisbee "Watch this!"?

[MindPilot]

6. I suspect that was bad piloting, not complicated maneuvering

Whoever was driving that airplane got lucky to hit that low that fast.

[Xenotime]

9. Provided it was a "plane"

[Hoping4Change]

12. It seems indisputable that a plane was involved as it was being

tracked by air traffic control. Whether it was Flight 77 is another story. My OP was not to question whether it was or wasn't a plane but simply to know why it took the route it did.

[bmcatt]

16. No, something with a transponder was being tracked

Most, if not all, of the "primary" air traffic control radar sites have been shut down in favor of "secondary" ATC radar.

Primary radar gives the classic "ping" and shows a blob on a screen which indicates "there's something here, but speed, direction of travel, and altitude are unknown"

Secondary radar is the result of a transponder query whereby the plane has (usually) a unique transponder code (certainly the case for airlines since they almost always fly IFR and aren't squawking 1200 - the VFR transponder code) which gives altitude. Because the transponder code is known, direction of travel can be determined and speed (at least approximately) is determinable from the ground station. The transponder itself (if it's "Mode C") is providing altitude information.

ATC will know, at best, that there's something there and that it's flying. They won't know anything about size or cargo / passengers.

[benEzra]

19. I seem to recall that all the hijacked planes had their transponders

turned off, and the reason ATC had such fits trying to track them was that few modern civilian radars track "skin reflections" anymore, due to the ubiquity of transponders. I may be wrong, though.

[bmcatt]

20. Which leads to an interesting question

Namely, if the transponders were turned off, how is it that we, theoretically, have such good information on where and how the planes were flying. For example, the only way that ATC could tell that the "plane" that hit the Pentagon did a 180 (or 270) degree *descending* turn would be if the transponder was on. There's *no way* that primary radar can provide altitude information. It's just an impossibility.

[Bouvet_Island]

21. I'm not sure if you are completely realising what you are saying

hitting the pentagon with the kind of maneuver they took requires flying blind through a 3D curve. You could liken it to something like hitting several tincans blindfolded at 100 feet from a rather fast merry-go-round. If someone did, there are several things I would like to completely rule out before even considering luck did it. With no black boxes from any planes and the peculiar approach to releasing evidence, it is an extremely suspicous claim that regular people muslims did it. I imagine it so difficult to find a person that both would have a reasonable chance at hitting, be bold enough and be stupid enough to try it agianst the type of odds you inevitably arrive at if you do the full math. Eg planning against what you would know about the us air defence, the hours of flights, managing passengers with cell phones, the threat of stingers or surprises at arrival (how did they know the Pentagon was unprotected? Wouldn't one expect that to be classified? How high a clearance would your source need to have to be certain about a question like that?), airport security, leaks, force major affecting anything. Would you accept an odds of 1:10 at hitting something at all if your name would be made history from it? What about 1:100 000 ? Or could you show how you would calculate the total risks any lower?

[rman]

25. Such extensive plotting, then amateur piloting,

and achieving the objective by sheer luck?

Not very plausible.

[Asgaya Dihi]

8. Hard to say

I've heard theories some have already mentioned, also that the Pentagon wasn't the intended target but a secondary that was hit when they couldn't pick out the first one. What's true if any, I don't have a clue. I do think a plane hit it, but there's also some questions left that neither side answers well enough to accept as fact rather than theory. More about the WTC than this one though.

[benEzra]

15. That's possible...

from the air, the White House and the Capitol are both a lot less recognizable than the Pentagon. There are a ton of gray rectangular buildings around the Mall, but the Pentagon is impossible to miss from the air.

[FogerRox]

22. just thought of this....

I dig WW2 stuff, F4-U Corsair pilots made a similar approach to the carrier when landing. The long nose of the F4-U made visibility a problem.

If I am to believe the (270 degree)story, its like landing on a carrier.

[Hoping4Change]

24. But the person who commandeered the plane was

according to his flight instructors an incompetent pilot. His skills didn't come close to the skills of military pilots.

[Old and In the Way]

27. Beats me.

He took a relatively easy attack approach and made it immeasurably more difficult. I would suggest anyone who has MS Flight Simulator to set up the approach using the 767 model in the most realistic settings and see if you can do it on the 1st attempt...or the 10th, for that matter.

[Hoping4Change]

28. So you are saying that there wasn't anything preventing the pilot

from diving into the building.

[bmcatt]

29. Aim for the bull's-eye

It's a heck of a lot easier target, requires almost no complicated maneuvers and doesn't have any interaction with the highway, ground, etc. Plus, you'd wind up splashing burning Jet A pretty much over the entire building.

Not that I'm minded to do so, but *if I were*, it's what I'd do. Also, if, by some really funky circumstance, I wound up, under power, aiming for the side of the pentagon and was worried at all about hitting it, I'd just pull up and do a go-around for a second shot at it. I sure as heck wouldn't commit to settling for a wall with a really odd approach.

[Old and In the Way]

30. If he came in over the WH (big if, IMHO), the Pentagon

is directly in front of him. I have to assume that the hijackers did their homework and would want to hit the area where all the top administrators would work....wouldn't that make sense? If so, they'd have had a much better chance of doing that on the inital approach. If they did overshoot the target, they could have made an easier, less severe turn that would have brought them back to that side of the Pentagon.

If you were going to attack the Pentagon, wouldn't you aim for the area where the SecDef would be?