Have Bombers become obsolete in Modern warfare?

[Yusuf]

2000 lb internal storage + 5000lb external storage (Total of 7000 lbs) per F-22. 7000 X 6 =42,000 lbs.

Gives away the stealth if external storage is used.

Besides the whole discussion about bombers in modern time is subject to affordability. No other nation operates a dedicated bomber force in large numbers apart from the US.

Besides with the advent of JDAMs, the argument of collateral goes out of the window. A JDAM costs 35,000 whereas a Tomahawk costs 600,000 each to deliver the same 1000lb of Payload. A B 2 can carry 80 500lb bombs which give it the option of bombing multiple targets. Use of ballistic missile like trident would not make sense in a conventional bombing scenario.

So if you can afford one, you can maintain a fleet of dedicated bombers. If not look for multi-role fighters.

 

[Sailor]

So if you can afford one, you can maintain a fleet of dedicated bombers. If not look for multi-role fighters. Yusuf quote.

Right on mate. Check this out.

Here it comes bad guys. Courtesy of Uncle Sam.

Refuel and then go back for another load.

 

[Su-47]

Gives away the stealth if external storage is used.

Sometimes stealth isn't necessary, like when bombing terrorist positions or when enemy air defence systems have been neutralised. In those cases it is much more cost-efficient to use strike fighters than bombers.

Besides with the advent of JDAMs, the argument of collateral goes out of the window. A JDAM costs 35,000 whereas a Tomahawk costs 600,000 each to deliver the same 1000lb of Payload. A B 2 can carry 80 500lb bombs which give it the option of bombing multiple targets. Use of ballistic missile like trident would not make sense in a conventional bombing scenario.

Sometimes even B-2 can't penetrate certain heavily defended airspaces. Some of the latest Russian radars boast stealth detection ability. They haven't been proven yet, but if it true, then B-2 is as useful as a B-52 only. Also, heavy fighter patrol over an area compromises B-2, since visual detection is possible. So in order to take out high priority targets behind heavy air defence, a cruise missile is needed. I know that even cruise missiles can be shot down, but they will have a higher success rate than a bomber whose staelth has been compromised.

So if you can afford one, you can maintain a fleet of dedicated bombers. If not look for multi-role fighters.

Completely agree with you there. As i said before, bombers are still effective, but their scope has reduced. However, it is still a desirable weapon to have, if you can afford it.

 

[Yusuf]

Sometimes stealth isn't necessary, like when bombing terrorist positions or when enemy air defence systems have been neutralised. In those cases it is much more cost-efficient to use strike fighters than bombers.

Are you suggesting the terrorists dont have access to SAMs?
Also during the Balkan War, the enemy was not a terrorist organization, but a well armed and trained army with SAMs. They managed to down one Night hawk. But then the conflict also saw a lot of B-2 sorties with no loss.

Sometimes even B-2 can't penetrate certain heavily defended airspaces. Some of the latest Russian radars boast stealth detection ability. They haven't been proven yet, but if it true, then B-2 is as useful as a B-52 only. Also, heavy fighter patrol over an area compromises B-2, since visual detection is possible. So in order to take out high priority targets behind heavy air defence, a cruise missile is needed. I know that even cruise missiles can be shot down, but they will have a higher success rate than a bomber whose staelth has been compromised.

On what basis are you able to say that the B-2 can't penetrate heavily defended airspace? Again, during the Balkan war, it did with impunity. The area was very heavily defended.
You cannot assume that some unproven Russian capability will detect stealth aircraft and say the B-2s are vulnerable.

 

[Su-47]

Are you suggesting the terrorists dont have access to SAMs?
Also during the Balkan War, the enemy was not a terrorist organization, but a well armed and trained army with SAMs. They managed to down one Night hawk. But then the conflict also saw a lot of B-2 sorties with no loss.

Sorry bout that. When i meant terrorists, i meant organisations like Taliban and Iraqi terrorists, who don't have any credible air defence systems. I wasn't talking of terrorist nations.

On what basis are you able to say that the B-2 can't penetrate heavily defended airspace? Again, during the Balkan war, it did with impunity. The area was very heavily defended.
You cannot assume that some unproven Russian capability will detect stealth aircraft and say the B-2s are vulnerable.

System maybe unproven, but doesn't mean it WON'T work. U can't underestimate the Russians. Also, even if B-2 ain't detected by radar, it can always be shot down if the enemy fires enough Anti-aircraft artillery (AAA) into the skies once B-2 releases its bombload (when for a instant, it becomes visible due to ordnance falling, especially if there are multiple bombs).

Yusuf, i'm not trying to underrate the B-2. It will work against MOST countries. But countries with a lot of aircraft and air defence, like Russia and China, maybe able to limit their usefulness. Against these countries, a fleet of F-22s will be more effective than the B-2.

 

[Yusuf]

Sorry bout that. When i meant terrorists, i meant organisations like Taliban and Iraqi terrorists, who don't have any credible air defence systems. I wasn't talking of terrorist nations.

No i did talk about terrorists as well. The Taliban have got their hands on the Gremlin. Never know when they have radars as well.

System maybe unproven, but doesn't mean it WON'T work. U can't underestimate the Russians. Also, even if B-2 ain't detected by radar, it can always be shot down if the enemy fires enough Anti-aircraft artillery (AAA) into the skies once B-2 releases its bombload (when for a instant, it becomes visible due to ordnance falling, especially if there are multiple bombs).

The Iraqis tried that. They use to fire blindly in the air when a bomb use to explode. They had no success. The B-2s dont hand around the area to see what the bombs did. They moved to the next target.

Yusuf, i'm not trying to underrate the B-2. It will work against MOST countries. But countries with a lot of aircraft and air defence, like Russia and China, maybe able to limit their usefulness. Against these countries, a fleet of F-22s will be more effective than the B-2.

I dont believe BIG nations will go to war, but they will fight through proxies like they did during the Cold War. The proxies are not mighty enough and capable enough. So systems like B-2s will continue to be effective.

 

[Rage]

2000 lb internal storage + 5000lb external storage (Total of 7000 lbs) per F-22. 7000 X 6 =42,000 lbs.

Again, I fail to understand how you come up with that figure. The F-22 has four under-wing pylon hardpoints, each theoretically capable of carrying either 600 gallon drop tanks or 5000lbs of ordnance. In the likely scenario that two of these pylon stations (the two inner hardpoints that are 'plumbed') contain drop tanks, the other two will contain external ordnance- which coupled with internal stores will total to an ordnance of 12,000 lbs per Raptor (5000lbs x 2 + 2000lbs). However, both the Raptor's Sargent Fletcher drop tanks and its external stores significantly increase RCS, and although stealth pods and drop tanks and related jetissonable hard points are being currently worked on, the Raptor's stealth ability is greatly compromised by external ordnance. Ergo the dual conundrum: to achieve a range of 1,600 nmi / 1,840 mi / 2,960 km (still significantly less than the B-2's 6,000 nmi), the F-22 must convey two external drop tanks, but doing so severely attenuates it's stealth ability. Conversely, to achieve the stealth requisite for a bombing mission, the F-22 must be divested of it's external stores and drop tanks, so that the only ordnance is the one present in its internal bay (a paltry 2000 lbs).

A future stealth bomber is not in the charts right now. Most nations today are trying to build stealthy 5th gen fighters and stealth UCAVs.

Incorrect. Please see:

TheStar.com | Business | Boeing, Lockheed team up on bomber project
Boeing: Boeing and Lockheed Martin Team for Next Generation Bomber Program


There was also the interim (to the 2037 bomber) proposed modified bomber version of the F-22 Raptor called the FB-22, featuring a lengthened fuselage, delta wings, improved stealth, a larger internal weapons bay and a greater range and payload- in the balance presently because of a paucity of funding due to the wars in Afghanistan and Iraq*.

Northrop Grumman also received in funding in 2008 to the tun of $2 billion for "restricted programs" or 'black programs' – for a technology demonstrator which could fly as early as 2010. []Ultra Stealth | AVIATION WEEK


* Amid conflicting rumours that the 2037 bomber was brought forward 2 generations and the FB-22 program was scrapped, Wikipedia mentions the FB-22 as "appear[ing] to be cancelled in lieu of a long range bomber with a much greater range than the FB-22" in the 2006 Quadrennial Review. However, there has been neither confirmation nor explicit mention of the cancellation of the program itself in the said QDR. If these rumours are true however, we could expect to see a next generation stealth bomber in as little as 10 years (in which case the FB-22 would almost certainly be scrapped, but with the research and advances concomitant of its development serving as a base for the former). Other reports have it that the 2018 bomber and the 2037 bomber are actually two distinct programs, with the former serving as an interim stop-gap measure. Further reports indicate that the USAF is expected to announce later this year its specific requirements for the 2018 bomber.


The PLAAF [XAC] is also rumoured to be working on an indigenous bomber project, said to resemble the Su-34, as a replacement for its ageing H-6 (Tu-16) medium bomber aircraft over the next tow decades:

Future Bomber Programme - SinoDefence.com


There are also reports of the Russians working on a prototype replacement for the Tu-160 called the PAK-DA (modified bomber version of the PAK-FA) through a consortium led by Sukhoi and Tupolev, and an estimated first flight date of 2015:

PAK-DA: Future Russian Bomber Project, page 1

Even supersonic stealth bombers are still not capable of multirole, and thats their biggest weakness. They have low sortie rates and are plagued by the same weaknesses of most bombers, the inability to clear the skies of enemy aircraft.

AFAIK, there is only one supersonic stealth bomber- a prototype: Project SD-36- that made its maiden flight at the Sergey Martin laboratory in Alpharetta, GA in October last year: Project SD-36 (Supersonic Scramjet Stealth Bomber) Maiden Flight - RC Groups

While the 'inability to clear the skies of enemy aircraft' is certainly a weakness, it is not what bombers are meant for. That role is limited to multi-role and combat aircraft- with their own mitigating features that limit their bombing ability.

Intercontinental strikes are losing their importance with the advent of ballistic missiles, and more importantly, long-range cruise missiles. An Ohio-class SSBN armed with Tomohawk missiles can deliver precision strikes with much less risk and higher chance of success.

Debatable. But my point was not to purport that as a primary function, merely to point out that range-extension through mid-air refueling is not something only combat/multi-role aircraft are privy to.

Please also refer to Yusuf's post regarding JDAM's. With the advent of JDAM's and integrated inertial guidance systems, previously "dumb" or 'gravity' bombs have now become "smart munitions" with significantly higher success rates.

 

[Su-47]

Again, I fail to understand how you come up with that figure. The F-22 has four under-wing pylon hardpoints, each theoretically capable of carrying either 600 gallon drop tanks or 5000lbs of ordnance. In the likely scenario that two of these pylon stations (the two inner hardpoints that are 'plumbed') contain drop tanks, the other two will contain external ordnance- which coupled with internal stores will total to an ordnance of 12,000 lbs per Raptor (5000lbs x 2 + 2000lbs). However, both the Raptor's Sargent Fletcher drop tanks and its external stores significantly increase RCS, and although stealth pods and drop tanks and related jetissonable hard points are being currently worked on, the Raptor's stealth ability is greatly compromised by external ordnance. Ergo the dual conundrum: to achieve a range of 1,600 nmi / 1,840 mi / 2,960 km (still significantly less than the B-2's 6,000 nmi), the F-22 must convey two external drop tanks, but doing so severely attenuates it's stealth ability. Conversely, to achieve the stealth requisite for a bombing mission, the F-22 must be divested of it's external stores and drop tanks, so that the only ordnance is the one present in its internal bay (a paltry 2000 lbs).

You are right. I made a critical error when calculating. EACH hardpoint can carry 5000 lbs of ordnance according to wikipedia. I thought 5000 lbs was overall capacity. So your figures are correct. Sorry bout that.

I was quoting unstealthed load capacity. Remember, stealth isn't needed in every situation, especially once air supremacy is achieved, which the USA usually achieves. In a situation needing stealth, its obvious that the 2000lbs internal storgae is woefully inadequate.

Incorrect. Please see:

TheStar.com | Business | Boeing, Lockheed team up on bomber project
Boeing: Boeing and Lockheed Martin Team for Next Generation Bomber Program


There was also the interim (to the 2037 bomber) proposed modified bomber version of the F-22 Raptor called the FB-22, featuring a lengthened fuselage, delta wings, improved stealth, a larger internal weapons bay and a greater range and payload- in the balance presently because of a paucity of funding due to the wars in Afghanistan and Iraq*.

Northrop Grumman also received in funding in 2008 to the tun of $2 billion for "restricted programs" or 'black programs' – for a technology demonstrator which could fly as early as 2010. []Ultra Stealth | AVIATION WEEK


* Amid conflicting rumours that the 2037 bomber was brought forward 2 generations and the FB-22 program was scrapped, Wikipedia mentions the FB-22 as "appear[ing] to be cancelled in lieu of a long range bomber with a much greater range than the FB-22" in the 2006 Quadrennial Review. However, there has been neither confirmation nor explicit mention of the cancellation of the program itself in the said QDR. If these rumours are true however, we could expect to see a next generation stealth bomber in as little as 10 years (in which case the FB-22 would almost certainly be scrapped, but the research and advances concomitant of its development serve as a base for the former). Other reports have it that the 2018 bomber and the 2037 bomber are actually two distinct programs, with the former serving as an interim stop-gap measure. Further reports indicate that the USAF is expected to announce later this year its specific requirements for the 2018 bomber.


The PLAAF [XAC] is also rumoured to be working on an indigenous bomber project, said to resemble the Su-34, as a replacement for its ageing H-6 (Tu-16) medium bomber aircraft over the next tow decades:

Future Bomber Programme - SinoDefence.com


There are also reports of the Russians working on a prototype replacement for the Tu-160 called the PAK-DA (modified bomber version of the PAK-FA) through a consortium led by Sukhoi and Tupolev, and an estimated first flight date of 2015:

PAK-DA: Future Russian Bomber Project, page 1

Hmm. I knew about the Russian project, not the others. but either way, these projects are sort of on the back burner. The article itself mentions how the FB-22 is paused. The Russian bomber depends on the success of the PAKFA, and the Chinese bomber seems more like a fighter bomber.

While it is clear these countries do want a bomber, nothing is finalised yet. Maybe a stealth bomber is on the charts, but not anytime in the near future. I know the article says Russian bomber will fly in 2015, but russian projects tend to be delayed. PAKFA itself hasn't even flown yet. God knows when that bomber will enter service. Not in the next decade for sure.

AFAIK, there is only one supersonic stealth bomber- a prototype: Project SD-36- that made its maiden flight at the Sergey Martin laboratory in Alpharetta, GA in October last year: Project SD-36 (Supersonic Scramjet Stealth Bomber) Maiden Flight - RC Groups

While the 'inability to clear the skies of enemy aircraft' is certainly a weakness, it is not what bombers are meant for. That role is limited to multi-role and combat aircraft- with their own mitigating features that limit their bombing ability.

Great find bro. Again, i was completely unaware of this (i haven't been paying attention to defence news) The SD-36 seems more of a tech demonstrator though.

The inability to clear the skies is exactly why the bomber is losing ground to the fighter. Non-stealth bombers are almost impossible to operate without aerial supremacy. Even stealth bombers will be overshadowed by their strike fighter cousins. The bombers low sortie rate and high maintenance cost is another factor. Its just much more cost effective to use a fighter to deliver that 500 lb JDAM. Bomber is only cost efficient when A LOT of bombs have to be delivered to a target area. So bomber is losing out to fighter not just in air-to-air role, but also cost effectiveness.

Debatable. But my point was not to purport that as a primary function, merely to point out that range-extension through mid-air refueling is not something only combat/multi-role aircraft are privy to.

Please also refer to Yusuf's post regarding JDAM's. With the advent of JDAM's and integrated inertial guidance systems, previously "dumb" or 'gravity' bombs have now become "smart munitions" with significantly higher success rates.

JDAMs can strike with a lot of accuracy, but it has to be delivered there. Imagine a scenario where a B-2 has to fly to a heavily defended target deep inside enemy territory. Enemy AAA is filling the skies with shrapnel. Enemy fighters are patrolling the skies (just outside the AAA firing range). There is a chance that the B-2 will be spotted by the fighters or be hit by the AAA on the way to the target.

Assuming it doesn't get hit, the moment it releases its payload, when the bomb bay opens and the unstealthed ordnance comes out, its position can be detected on radar, albeit for a very short time. But that's enough for the fighters to get a rough idea of the bomber's location. If they visually spot the B-2, its game over. More than a billion dollars down the drain. Now Yusuf mentioned the case in Iraq, but Iraq didn't have good Air defense systems, or much fighter patrol. That won;t be the case with a lot of other countries.

Isn't it much less risky to use a cruise missile? A sub can launch the cruise missile while submerged, and from a very long distance, away from enemy detection systems, and then just vanish into the depths.

However, a bomber (preferrably stealth) will be an excellent platform to carry a cruise missile to just within reach of a far-away target, and then launch the missile and scarper before the enemy fighters arrive.

 

[Yusuf]

JDAMs can strike with a lot of accuracy, but it has to be delivered there. Imagine a scenario where a B-2 has to fly to a heavily defended target deep inside enemy territory. Enemy AAA is filling the skies with shrapnel. Enemy fighters are patrolling the skies (just outside the AAA firing range). There is a chance that the B-2 will be spotted by the fighters or be hit by the AAA on the way to the target.

Assuming it doesn't get hit, the moment it releases its payload, when the bomb bay opens and the unstealthed ordnance comes out, its position can be detected on radar, albeit for a very short time. But that's enough for the fighters to get a rough idea of the bomber's location. If they visually spot the B-2, its game over. More than a billion dollars down the drain. Now Yusuf mentioned the case in Iraq, but Iraq didn't have good Air defense systems, or much fighter patrol. That won;t be the case with a lot of other countries.

Isn't it much less risky to use a cruise missile? A sub can launch the cruise missile while submerged, and from a very long distance, away from enemy detection systems, and then just vanish into the depths.

However, a bomber (preferrably stealth) will be an excellent platform to carry a cruise missile to just within reach of a far-away target, and then launch the missile and scarper before the enemy fighters arrive.

Iraq did have good air defense, but it was all taken out in the initial SEAD/DEAD missions. And you cannot randomly keep firing in the air with AAA whole day thinking that one will hit a B-2. Also the US had good intel on where the ground radars of the Iraqis were located and the range of it. So it used it to bye pass such installations. All bombing missions were in the night and that helped as well as ground based visibility is zero. Besides with a ceiling of 50,000 ft, the B-2 is out of reach of the Flaks.

Cruise missiles are used in the extremely high risk and on off operation. They are very expensive. like i mentioned before, the B-2 can deliver 80 JDAMS with one JDAM having the same explosive power as the Tomahawk. One JDAM costs $35,000 and one Tomahawk costs $600,000. Make the calculation.

Besides the inventory of the JDAMS is far greater than the Tomahawks. They cant be used randomly for all missions. They are used only if there is particular intelligence on a high value target and then used as its deployed faster.

 

[Zmey Smirnoff]

^^^ Iraq had more or less decent SAM coverade in 1991. It was completely decimated during the Gulf-War-1 and by the time of OIF, virtually none remained. In 2003 USAF as a whole and B-2 in particualr operated with virtual impunity from SAMs.

 

[Su-47]

Iraq did have good air defense, but it was all taken out in the initial SEAD/DEAD missions. And you cannot randomly keep firing in the air with AAA whole day thinking that one will hit a B-2. Also the US had good intel on where the ground radars of the Iraqis were located and the range of it. So it used it to bye pass such installations. All bombing missions were in the night and that helped as well as ground based visibility is zero. Besides with a ceiling of 50,000 ft, the B-2 is out of reach of the Flaks.

Cruise missiles are used in the extremely high risk and on off operation. They are very expensive. like i mentioned before, the B-2 can deliver 80 JDAMS with one JDAM having the same explosive power as the Tomahawk. One JDAM costs $35,000 and one Tomahawk costs $600,000. Make the calculation.

Besides the inventory of the JDAMS is far greater than the Tomahawks. They cant be used randomly for all missions. They are used only if there is particular intelligence on a high value target and then used as its deployed faster.

The Iraq situation is different from what i had in mind. Iraq had a lot of AA, but most were antiquated Russian cold war equipment, especially in the 2nd war. Also, as i mentioned, Iraq didn't have a proper air force to boast of. So even when the bombs started falling, they could only fire blindly. It will be a different case if the opposing nation is a strong military power, like Russia (i know its unlikely, but hypothetically). The moment the JDAMs drop, the MiGs and Sukhois will fill the skies around the area, making it hard for the B-2 to escape.

But as you said earlier, if a proxy is used, the B-2 is a better option than a Tomohawk. But however, if proxy is used, it will be easy for USA to establish an airbase near the proxy, and then it'll be more worthwhile to use stealth strike fighters than B-2s.

 

[Yusuf]

Though the US had bases in Saudi, Qatar, Bahrain, all strikes strikes of B-2 took place from the Whiteman air base in the US. The US does not want to base any of its premium aircraft anywhere else other than the US.

 

[Su-47]

Though the US had bases in Saudi, Qatar, Bahrain, all strikes strikes of B-2 took place from the Whiteman air base in the US. The US does not want to base any of its premium aircraft anywhere else other than the US.

Thats mainly coz the B-2 needs heavy maintenance that other air bases cannot provide. The US bases around the world have neither the infrastructure nor the technicians to provide the maintenance required.

This illustrates another weakness of heavy bombers. They need large airbases with long runways and huge hangars and repair infrastructure, which limit their flexibility. It takes several hours for a bomber to make an airstrike. They have to fly from their far flung bases to targets that are thousands, or tens of thousands of kms away.

Compare this to strike fighters like the Gripen, which can operate from a stretch of highway.

 

[Yusuf]

Thats mainly coz the B-2 needs heavy maintenance that other air bases cannot provide. The US bases around the world have neither the infrastructure nor the technicians to provide the maintenance required.

This illustrates another weakness of heavy bombers. They need large airbases with long runways and huge hangars and repair infrastructure, which limit their flexibility. It takes several hours for a bomber to make an airstrike. They have to fly from their far flung bases to targets that are thousands, or tens of thousands of kms away.

Compare this to strike fighters like the Gripen, which can operate from a stretch of highway.

My response was to you post in which you said that it would be better to establish air bases in the proxies.

You cannot compare Gripen to the B-2 can you?

 

[Paritosh]

yes bombers are totally obsolete now....not only are they vulnerable...to being shot and compromising their mission...but they also are manned and put a trained pilot which is a huge investment to a country at risk...
modern ballistic missiles do whatever a bomber can...and even extra....they are faster...better maneuverable....and accurate...and plus are unmanned...so IMO...missiles are the new and better unmanned bombers...

 

[Yusuf]

yes bombers are totally obsolete now....not only are they vulnerable...to being shot and compromising their mission...but they also are manned and put a trained pilot which is a huge investment to a country at risk...
modern ballistic missiles do whatever a bomber can...and even extra....they are faster...better maneuverable....and accurate...and plus are unmanned...so IMO...missiles are the new and better unmanned bombers...

Ballistic missiles are not maneuverable. Cruise missiles are.
We have been discussing quite a bit of the pros and cons of this. Maybe you can go through all of those posts and give us your thoughts.

 

[Zmey Smirnoff]

yes bombers are totally obsolete now....not only are they vulnerable...to being shot and compromising their mission...but they also are manned and put a trained pilot which is a huge investment to a country at risk...
modern ballistic missiles do whatever a bomber can...and even extra....they are faster...better maneuverable....and accurate...and plus are unmanned...so IMO...missiles are the new and better unmanned bombers...

First of all, BMs are not nearly as flexible as bombers. You cannot return or redirect a BM once its launched. Second, if you calculate the per kg cost of delivering explosives to predetermined range you'll find that BM are exuberantly expensive. Thats the main reason three major military powers in the world maintain bomber fleets and have no intention to retire them.

 

[Zmey Smirnoff]

Ballistic missiles are not maneuverable. Cruise missiles are..

Cruise missiles are able to maneuver - but they are not maneuverable in the same sense a manned aircraft is. CM does not maneuver to avoid a threat, but merely to avoid an immovable obstacle. CMs will fall prey to even the most basic interceptors for as long as the have look-down/shoot-down radar.

 

[Yusuf]

Right. I was just telling Paritosh that BMs are not maneuverable but only cruise missiles are. That apart Bombers have their own role and ive said before that if you can afford to, you should have a fleet of it.

 

[pyromaniac]

Compared to the early years of the cold war, the Bomber is all but obsolete but a dedicated bomber force can still be useful. Granted against a modern air force, the bomber will be a sitting duck and will need to be protected by fighters but nothing can match the pure and directed firepower of a bomber. With that said though, it is interesting to note that the missiles might outstrip everything in usefulness and lethality including fighters.
I am sure we will not see countries pouring in billions of dollars into dedicated bomber programs(Like the B-2) rather we will see multi role aircraft (F/A-18, Su-30's) take a more important rule with bombers forming a "second line" of defense used to put down massive grouped units/targets once Air superiority has been achieved over a area.