Thought experiment: Pearl Harbour as a 9/11 target

[dtugg]

They (both the ships and the base) have these things called radars and missiles and big guns & big bullets. The former thing can determine any flying object's speed and trajectory within range in a fraction of a second after spotting it and track them constantly for instantaneous recognition of unexpected changes, with automatic alerts going off if the change is a dangerous one. The latter two things can arrive at a target a mile away in a few seconds or less. The people operating these systems would have time to wait and watch the clock to give the target until the last moment (before it would cross the "too late" line and have to be clobbered) to resume a normal course.

Sounds like a good way to accidentally shoot down a regular commercial airliner to me seeing as how they approach from over Pearl Harbor to land.

 

[Corsair 115]

And those cannons would be of little help against a 777 heading straight for it at 500mph.

The Phalanx CIWS was designed to shoot down incoming fast-moving anti-ship missiles as well as aircraft. It fires up to 75 rounds per second of 20mm cannon shells. I would think 75 rounds of 20mm cannon fire impacting a civilian jetliner would quickly spell the end of that jetliner. (Plus that jetliner is a much bigger target that an anti-ship missile.)

 

[Delvo]

The Phalanx CIWS was designed to shoot down incoming fast-moving anti-ship missiles as well as aircraft. It fires up to 75 rounds per second of 20mm cannon shells. I would think 75 rounds of 20mm cannon fire impacting a civilian jetliner would quickly spell the end of that jetliner. (Plus that jetliner is a much bigger target that an anti-ship missile.)

One second's worth might not do it, particularly if it hit the center of the target, which is the nose instead of the cockpit or engines, but each unit has enough ammo for a total of about a minute and a half of sustained fire, which is well over what would be needed to chew it to pieces, and they could aim for engines, and the ship has more than one such unit, and the claim that this is the only self-defense system on the ship was false; it also carries at least a couple of types of defensive surface-to-air missiles... and that's still to say nothing of the fact that there'd be other ships in port too and the naval base itself has its own sensors & weapons.

 

[Dave Rogers]

Just so I am clear (again, I know nothing about the military, just using common sense here), an Aircraft carrier can defend itself against a hostile enemy fighter jet, yet it is helpless against a commercial aircraft piloted by a nut.

I get that they don't have a whole lot of time to make the call, but when an enemy fighter is attacking I am guessing they don't wait for you to get ready.

On the contrary, enemy fighters tend to give a lot of warning. They do this by only attacking when there's either a state of war in effect - in which case the aircraft carrier will be protected by a combat air patrol and a task force of escorts - or a hostile aircraft carrier or air base within range and a strong likelihood of war being declared. An aircraft carrier can defend itself very easily in time of war from a commercial aircraft piloted by a nut; in fact, it's a lot easier to defend anything when the population is aware that there's a genuine threat to defend against. The problem is that, when there isn't a war going on, it's difficult to defend anything against a surprise attack by a small group.

Dave

 

[Ferguson]

But how much damage could it do, assuming they have no chance to shoot it down?
I would think an aircraft carrier would be armored and designed to take impacts from actual warheads. A civilian skyscraper full of computers, desks, carpets, etc. makes great kindling for a fire caused by an airplane. I would think the airliner would just burn up on the carrier's runway. Maybe they could do some damage to the flight control tower, but I find it hard to believe it would have any chance of actually sinking the thing.

Am I way off base?

 

[Halfcentaur]

I think it would have really boosted the dramatic nature of the attacks if they had people simultaneously attacking Pearl Harbor at the same time as they hit the WTC and the Pentagon. But that would have really spread out their forces in way that makes the logistics a bit too excessive in my mind. But, IF this did happen, I think America would have reacted much more harshly than it did in it's response.

 

[Corsair 115]

But how much damage could it do, assuming they have no chance to shoot it down?

The kinetic energy of the aircraft impacts into the WTC towers was about equal to the explosive power of a 2,000-lb. bomb.

 

[Travis]

The Phalanx CIWS was designed to shoot down incoming fast-moving anti-ship missiles as well as aircraft. It fires up to 75 rounds per second of 20mm cannon shells. I would think 75 rounds of 20mm cannon fire impacting a civilian jetliner would quickly spell the end of that jetliner. (Plus that jetliner is a much bigger target that an anti-ship missile.)

Yes, but in this instance you wouldn't know the aircraft would need to be intercepted until it was so close that you could spray the aircraft with cannon shells, knock out every engine and still get hit by the aircraft debris. Once the airliner is within a mile not much is going to stop all that mass barreling down at you at 500mph.

 

[catsmate]

I guess that would have been possible. After all, Hawaii does have international airports and aircraft carriers do occasionally berth at Pearl Harbor.

However, my guess is that the 9/11 hijackers would have found it easier to crash their planes into a very large stationary building as opposed to something smaller and moveable like an aircraft carrier.

And while an aircraft carrier is large for a ship, it is still much smaller than the World Trade Center Towers or the Pentagon Building.

The Nimitz class, as an example, are approximately 11m high over the water whereas the Pentagon is 23m making a side on approach (especially in an obstructed bay) far more difficult. The carries also have a degree of armour protection. And locally controlled self defense weapons.

 

[Gawdzilla Sama]

If terrorists are looking for a target in Pearl Harbor, the battleship Missouri is now preserved there as a museum ship. That would be a symbolic target.

Much like a windshield is to a bug.

 

[Delvo]

I would think an aircraft carrier would be armored and designed to take impacts from actual warheads... I would think the airliner would just burn up on the carrier's runway. Maybe they could do some damage to the flight control tower, but I find it hard to believe it would have any chance of actually sinking the thing.

Am I way off base?

Some of Bin Laden's Saudi friends said in interviews soon after the attack that they were surprised that the towers collapsed, because all that had been planned on and hoped for was a fire to burn up the floors at and above the impact points. So with a ship, sinking might not have been the goal either. It might have been, though, since people don't often think of merely damaging boats without thinking of sinking them.

Yes, but in this instance you wouldn't know the aircraft would need to be intercepted until it was so close that you could spray the aircraft with cannon shells, knock out every engine and still get hit by the aircraft debris. Once the airliner is within a mile not much is going to stop all that mass barreling down at you at 500mph.

Only if you figure either that lift, thrust, and drag make no difference in trajectory, or that the original trajectory was going to pass over the target instead of hitting it... and ignore passenger planes' low-density, high-surface-area construction. And debris isn't nearly as bad as getting hit by the whole plane anyway.

 

[Foolmewunz]

They (both the ships and the base) have these things called radars and missiles and big guns & big bullets. The former thing can determine any flying object's speed and trajectory within range in a fraction of a second after spotting it and track them constantly for instantaneous recognition of unexpected changes, with automatic alerts going off if the change is a dangerous one. The latter two things can arrive at a target a mile away in a few seconds or less. The people operating these systems would have time to wait and watch the clock to give the target until the last moment (before it would cross the "too late" line and have to be clobbered) to resume a normal course.

As DTugg pointed out, the AFB and the International (commercial) airport share at least one runway. There are blips on the radar there all the time. If one of those blips is an approaching 747 that radios that it's having trouble with its landing gear and is going to pull up and make another pass, and vectors over the left a few degrees(using some fancy-dancy Darth Rotor/Hutch pilot lingo, I'm sure), and continues at 400 mph(665 kph), then the guys on the ship have less than one minute to decide if that was a credible/legitimate distress situation and that the pilots path is therefore explainable, or if it's a 747 commandeered by persons with bad intentions and they should shoot it down. At 400 mph, the plane could make it from the airport to Pearl in about 50 seconds. In short, in about the time it's taken to read this paragraph, decide ((NOW!!)) if you shoot it down.

The way to stop planes from being hijacked and flown into targets is not to outgun the planes. It's to secure them so they can't get hijacked in the first place.

 

[Varanid]

It seems as though there are differences of opinion on if this is a valid method of attack.

My point is that if it is this easy to sink an aircraft carrier, then someone has really missed a huge contingency. This (to my knowledge) is not one of the hallmarks of the US Navy.

If you can't protect them at Pearl Harbor (or any other place) then they shouldn't be there.

 

[dtugg]

It seems as though there are differences of opinion on if this is a valid method of attack.

My point is that if it is this easy to sink an aircraft carrier, then someone has really missed a huge contingency. This (to my knowledge) is not one of the hallmarks of the US Navy.

If you can't protect them at Pearl Harbor (or any other place) then they shouldn't be there.

Somebody would have to hijack a plane first. Nowadays, it seems almost impossible that they would be able to do so. I don't think there is much point in worrying about it, certainly not enough to never go to Pearl Harbor. Besides, carriers don't very often port at Pearl; none of them are based there. They might stop for a few days on the way to or from San Diego or Washington but I don't think this is announced beforehand. I had no idea that the USS Carl Vinson (the ship from which the piece of garbage known as Osama bin Laden was disposed) was coming here to Hawaii until it already happened.

 

[Travis]

It seems as though there are differences of opinion on if this is a valid method of attack.

My point is that if it is this easy to sink an aircraft carrier, then someone has really missed a huge contingency. This (to my knowledge) is not one of the hallmarks of the US Navy.

If you can't protect them at Pearl Harbor (or any other place) then they shouldn't be there.

They can't really protect them at Norfolk either. And, as the real 9/11 showed, the Pentagon is rather vulnerable as well.

Of course what really protects these assets is the threat of retaliation. Sure you could temporarily damage one of these ships (it's exceedingly hard to actually sink an American aircraft carrier) but that means there are ten others that will now be mobilized to get you. There's two more in reserve as well that could be ready around the same time the one damaged is repaired. That would mean 13 of the bad boys are now available provided there are enough naval air crews to outfit them.

So, in reality, a surprise attack that sidelines one of the carriers for six months to a year is actually probably not worth it.

 

[Varanid]

How is the White House protected from this happening?
Big "no-fly" zone, right?

Shouldn't there always be one in place around such a piece of hardware? Doesn't that just make sense?

I see tinges of cold war error logic in your response Travis (not attributing it to you necessarily), which does make sense. Surely the Russians wouldn't try such a tactic. However, in our post 911 world, shouldn't this be at least on the radar?

Whom would we retaliate against in a stateless attack? Isn't that part of the rub in the first place?

I have to say, the evolution of my thought in this thread is funny (to me). I initially thought that the most advanced piece of military hardware out there could protect itself from a nut hijacking a 747. Hence, I wasn't concerned. Now, seeing multiple arguments explaining that they can't do so, I wouldn't say I am concerned, just that I find it upsetting that they aren't taken care of better than this.

 

[dtugg]

How is the White House protected from this happening?
Big "no-fly" zone, right ?

Commercial airliners fly near the White House all the time. It is a few miles away from Reagan National Airport. If some nut was at the controls while the plane was heading in, it seems likely that they could crash it into the White House.

Shouldn't there always be one in place around such a piece of hardware? Doesn't that just make sense?

Not if it a few miles away from a major airport.


The best defense against terrorists hijacking planes and flying them into buildings or ships is to prevent them from hijacking the planes in the first plane. Post 9/11, it is extremely unlikely that someone would be able to hijack a commercial airliner in the US.

 

[Delvo]

There are blips on the radar there all the time. If one of those blips is an approaching 747 that radios that it's having trouble with its landing gear and is going to pull up and make another pass, and vectors over the left a few degrees... At 400 mph, the plane could make it from the airport to Pearl in about 50 seconds.

And during the whole time not only would its map position be tracked, but so would its elevation...

 

[Foolmewunz]

And during the whole time not only would its map position be tracked, but so would its elevation...

And the guy tracking it would say,
"Oh, that's the plane with the landing gear problem... no worry."
And the guy next to him might say, "Hmm, maybe you ought to call in the Commander, just in case."
"What, and wake him - he had a long watch - you wake him if you're worried!"
"Nuh uh, not me."
And by that time the 747 is in the conning tower.

I'm really kind of amazed that there are people who want to believe in some sort of invincibility quotient, here. A carrier's invincibility is as good as the protection around it. In the middle of the Indian Ocean, there's a whole 2000 km of distance separating the carrier from the bad guy flying out to crash into him. And when he gets there, not only are their fighters aloft, but there's an entire escort group, replete with Aegis technology, ready to take him down before he gets within 20 miles of the target.

Any terrorist worth his salt would know that that sort of attack won't work. And hostile powers? Add to that protection the threat of retaliation for even trying. There are, I believe four other carrier groups in the Indian and Pacific at any given time. So the reprisals would likely be swift and fearsome.
Ashore? The carrier is not docking and giving R&R to crew where the USN does not feel it is safe, believe me. A carrier in Pearl or in San Diego is not going to be on full alert. They're relying on the lack of will of someone do come and do nasty things, intelligence, law, etc.....

I've seen carriers here in Hong Kong. U.S. carriers. The Nimitz, the Reagan, etc... And they berth right on the flight path to the international airport. While the crew is at liberty, they are not sharing naval intelligence with the Chinese, so they are on alert, at least somewhat. But the time required for a whacked out China Eastern pilot already coming down to 7000 feet for landing to simply point it down and throttle it up, would be far less than the minute I allowed in my other scenario. And don't try to tell me the magic ack-ack guns would be primed and ready and cut him to shreds. It'd take them several minutes to simply identify the target and determine what it was up to.

There are numerous factors involved in protecting military assets. Self-defense is merely one of them and you guys are making it out to be the be all and end all of the discussion. It's merely a part of it.

 

[Delvo]

And the guy tracking it would say,
"Oh, that's the plane with the landing gear problem... no worry."
And the guy next to him might say, "Hmm, maybe you ought to call in the Commander, just in case."
"What, and wake him - he had a long watch - you wake him if you're worried!"
"Nuh uh, not me."
And by that time the 747 is in the conning tower.

Either the plane is on a course to actually hit the ship, or it isn't.

I'm really kind of amazed that there are people who want to believe in some sort of invincibility quotient... don't try to tell me the magic ack-ack guns...

This kind of stuff is the behavior of somebody who has no actual case to make for his/her position and has decided to plug his/her ears and refuse to apply any reasoning.

It'd take them several minutes to simply identify the target and determine what it was up to.

That is a very ignorant comment. If over a dozen new targets showed up at once, that would bog down a modern military radar system so much that the task of identifying and determining the position and trajectory of all of them (so nobody's sitting around guessing whether they're headed toward the ship because they know) might be slowed down all the way to a couple of seconds.