Why do we need the B2 Spirit?

Your claim is pointless and has no base under it.
There is no video of B-2 in IR avaliable simply because there are none. I also may claim that it would be a great factual proof for it's significantly reduced signature, so if there is no video avaliable Nortrop have something to hide.

 

Errr, you are aware that we have not built any of these since 2000, are you not?

 

This is actually half-right.

Yes, RADAR does not have much of a problem "tracking" stealth aircraft. After all, as I frequently remind people "Stealth does not mean Invisible".

However, watching one of these is not like watching any other aircraft. WIth most aircraft the RADAR gives you a return that gives you a good idea of what the aircraft is (by size and speed), where it is going, altitude etc. Within moments of seeing an F-18, we can tell you what the aircraft most likely is, and we can clearly see it's flight path.

With stealth aircraft, it is not so easy. The easiest way to explain it is that we see a "ghost" on the RADAR screen, a track that appears and disappears, and is not clearly identifiable because so little is actually reflecting. The only way we know it is a real target and not say a flock of birds (which can show up the same way) is that a flock of birds does not go at over 300 mph at 30,000 feet.

Stealth does not actually do much for tracking, remember that Iraqi forces were able to detect our Stealth aircraft flying towards Baghdad with little problem. The big difference however is that they were never able to get enough of a return signal to actually engage them. That is where stealth really matters.

Air Defense (and air to air) systems need a large enough RADAR signature to track before they can engage anything. You can't simply volley fire them blind and hope to hit something. Without a clear RADAR (or heat) track, there is no engagement. And that is what stealth is really designed to do.

Not make an "invisible" plane, just make one that has a RADAR signature so small that weapons can't easily engage it.

Stealth Plane:



Invisible Plane:

 

I am far from being an enlitened person in radiolocation, but that stuff you are saying might work in a small range of wave length. Long wave BWR radars are claimed to be almost immune to any kind of existing stealth technology.

If i remember correctly total amount of hours spend by F-117 over Iraq scored less than 1% of total flight time by all aircrafts combined. In other words with so poor perfomance of Iraqi army and air defences with so poor number of aircraft shot down (~30) it is completely wrong to make any assumptions about stealth aircraft effectiveness. Just like making assumptions about about stealth aircraft effectiveness based on bombing of Yugoslavia with stealth aircraft being 50% of total loses...which is one aircraft out of two. Statistical samples are too small.

Question is if it worth to build entire airframe on this concept or not.

 

I am not going to get into the differences between pulse and doplar RADAR, but this is indeed how it works.

And while I will not comment on the differences in detection between long and short wave RADAR, I will say that while long wave is good for detection, it is pretty much worthless for acquisition and guiding of weapons. It is simply to farsighted to make an effective tracking system.

This is basically the same problem that Over The Horizon RADAR suffers from. It can sense that there is something outside of it's direct line of sight, but nowhere near enough of a return to guide any kind of weapon towards it.

That is because of a great many thing, but mostly because the F-117 had very specific missions, and were not used for everything simply because there were not enough of them, and not every mission needed that kind of platform.

And while they did fly a small percentage of missions, they made up almost 40% of the strategic targets engaged. Primarily Command & Control facilities, power facilities, communications facilities, and air defense sites. And it was their targeting of those ADA locations that enabled the more conventional aircraft to go after their targets.

The idea of the F-117 is to enter airspace which has a high number of defensive systems, like Baghdad (which was among the most heavily defended places on the planet). And while they did see the aircraft were on the way, they were unable to attack them with missiles, instead spraying the air with manually guided artillery and direct fire weapons.

And for the effectiveness in Yugoslavia, it did force Serbia to withdraw from Kosovo, so I would say it was effective. But once again, it was not just the F-117 operating there, but over 1,000 NATO aircraft, as well as Naval forces. And the F-117 was primarily used against the most heavily defended locations (once again primarily ADA sites).

And the one F-117 lost in combat was lost due to a very smart individual. The Commander of a Serbian SAM Battalion frequently moved his launchers and RADAR, and had another unit act as a decoy. He ordered his RADAR to operate in a stand-by mode, and waited for the Nighthawk to appear (he had it tracked visually). When it was overhead he fired up his RADAR< and fired at least 6-8 SA-3 missiles at it, catching it while it's bomb bay doors were open.

That is the time when it is at it's least "stealthy" mode, and had the highest chance of hitting. This was not a failure of the aircraft, as much as superior tactics by the SAM commander. The same tactic was later used to shoot down an F-16 in the same area.

You have to realize, Stealth Aircraft are not used on every mission. Only if the target is considered to be defended enough that sending in conventional aircraft would likely not accomplish the mission. And then they go after high-value targets, not just routine targets like bridges and supply dumps.

 

Well, forewarned is forearmed, right? When all means of detection are united in a common network you can not only prepare for the impact, but also focus all proper means of counterattack on the threatened direction. Anti-radiation and heat-seaking missiles included. Stealth is useful feature but it is untimately stupid to make it the only defencive line aircraft have.

Who said conventional aircraft couldn't have the job done? Since a lot of those missions were jamming/disrupting communications. Iraq didn't have much of a chance with F-117 or without.
Another recent example:Lybia. No significant use of stealth aircraft, yet all objectives achieved with only one F-15 lost. All long range SAMs were killed with cruise missiles and the rest couldn't reach altitudes from wich multirole fighters performed their strikes.

If you count AAA as a serious threat.

That was more of a political decision, than military defeat. Just like Vietnam or first chechen campain.

You have to realise that F-117 was opposing systems much older than itself, supported by a huge number of it's non-stealthy compatriots. Hardly a fair fight. Heavyweight fighter put fighter in the ultra lightweight to the canvas in the first round. Congrats, but hardly a surprise.