Are strategic bombers still useful, or are fighters taking over this role?

Question

During the mid 20th century and cold war, armies were having clear distinction between those aircraft designed as strategic bombers and those designed to be fighters for aerial combat. My understanding was that there were few exceptions to this rule.

However, the fifth generation of jet fighters include models designed normally for aerial combat but also used for strategic bombing. Old designs of strategic bombers are still being used, but it is clear that jet aircraft are being significantly improved by new developments compared to obsolete bombers.

Why is this happening? Is current warfare no longer requiring strategic bombers? Are designs of jet fighters so flexible that they can perform different missions? (usually it is the other way around, as time passes more specialization is seen).

Answer 1

The reason that small aircraft are used in the bombing role is flexibility and cost. If you load up a B-52, it can only be in one place at one time, travel at subsonic speeds, and be expensive to operate, risking more crew and equipment. Using smaller attack jets allows reaching targets across a wider geographical area faster. And while past conflicts saw massive bombing campaigns that favored the use of large bombers, more recent conflicts have seen much less of this tactic. Smaller, more targeted strikes are more typical, where a large bomber would be overkill.

Take a look at the cost per flight hour for various aircraft. A B-52 will cost \$70,000 per hour to operate, and a B-1B \$60,000. Compare this to an F-16C for \$23,000 or an F-15C for \$42,000. The A-10 costs \$18,000. For stealth, the costs go up to \$170,000 for a B-2 and \$70,000 for an F-22. So why send a B-52, when a few F-16's would cost the same amount? The fighters will also be able to defend themselves, and still be able to carry out a mission if an aircraft drops out. The same argument can be made for the stealthy class.

Strategic bombers still have their uses, but the bomber role is much less demanding than the fighter role. With proper maintenance and multiple equipment upgrades, old bombers can still fly bombs to their targets just fine. Fighter jets have much more complicated requirements, such as stealth, speed, and maneuverability, where advances in technology will justify the costs of continued development of new designs.

Aircraft are becoming more generalized because it is more efficient. In some areas such as naval aviation, this is even more critical. Why have separate planes for electronic warfare, attack, and air defense? You would be limited to a certain number of each type, with little or no cross capability. But with more generalized aircraft, you can have more aircraft with a certain capability across the fleet. If a certain capability becomes less important, you don't end up with a whole group of aircraft becoming useless. Aircraft can fulfill multiple roles in a single mission or deployment.

Answer 2

There are very few mission profiles in modern (post-WWII) combat that call for "carpet-bombing" of the type that the WWII-era medium and heavy bombers were used for. The primary target of a strategic bombing campaign is typically a city or other highly-populated area. During WWII it was considered a necessary evil, as high-value military-industrial targets were typically located in these cities and the accuracy (and power) of bombs was sharply limited, usually requiring an entire wing of bombers to ensure complete destruction of the target. This approach has since has been eschewed as barbaric by nations with significant air forces.

Technologically, advances have continued to chip away at the heavy bomber's mission profile. Small, precision bombing campaigns have always been given to light bombers like the Stuka, Mosquito and Mitchell, and in later eras the F-100 Super Sabre, F-105 Thunderchief (aka the Thud), A-6 Intruder and A-7 Corsair. These later aircraft used the development of the electronic fire control computer to dramatically increase the precision of unguided weapons, which along with their greater speed against enemy interceptor aircraft rendered the familiar sight of a sky darkened with large bombers unnecessary. In modern warfare, there are few dedicated small ground attack aircraft (the A-10 being a notable exception designed for close air support), most of that going to "multirole" aircraft such as the F-16 and F/A-18, with a few "deep strike" fighters like the F-15E (and when a similar mission profile but more firepower is called for, the B-1B finds its niche). These fighters handle the majority of offensive operations against high-value targets and enemy air defenses ("Wild Weasel" missions), with the A-10, AC-130 and Army helicopters handling the direct threats to infantry and armor.

In the early Cold War era, the best and biggest reason to keep heavy bombers like the B-29, B-48 and B-52 was that they were the only suitable vehicle for the delivery of strategic nuclear weapons (>1Mt). These weapons were phased out of the U.S. arsenal with the introduction of the MIRV-capable ICBM, able to carry the same total payload much farther, faster and with less impact of attrition by defenses, and shortly afte the dissolution of the Soviet Union, the Strategic Air Command itself, the single largest operating authority of the B-52 in history, was dissolved.

The last big reason to have something like a B-52 in theater is the ability to loiter indefinitely (at least 24 hours at a stretch). B-52s have the size and crew space to allow for crew rotations (you're not going to find Stearns and Foster mattresses aboard, but there are a few places to stretch out and kip, and there is a crude lavatory known sarcastically as a "honey bucket"), and with in-flight refueling, the only serious limitations to flight time are the capacity for on-board food stores and the eventual depletion of munitions. The B-52 can be equipped with 336 GPS-guided JDAM weapons, and a B-52 loitering at 50,000 feet over a theater like Afghanistan can be directed via AWACS/JSTARS to drop a guided bomb at a target with no visual line-of-sight needed. If air defenses are a potential problem, it has far-BVR capabilities when using cruise missiles like the JSOW, though it can carry fewer of them. This is the B-52's last stronghold, and it's a significant one; given various upgrades for efficiency and technological improvement during its life, the USAF plans to maintain a modest number of these aircraft until at least 2040.

Answer 3

Fighter aircraft have steadily grown in size and mass over the last century, as performance requirements and their armament load spiraled upwards. This has reached a point where a single seater today will carry more ordnance and fly farther than a strategic bomber from 70 years ago.

With their size and performance, the price of a single aircraft went through the roof, such that now one single aircraft design must fulfill many roles where 70 years ago several companies could offer competing designs for specialized roles. The development of strategic bombers has effectively stopped several decades ago with the XB-70, the B-1 and the Tu-160 because it became unaffordable. Note that I did not mention the B-2: It must be judged an economic failure, being so expensive that it rarely is used in earnest for fear of losing just a single plane. Instead, bombing missions today are performed by the smallest and lightest front line fighters, because here single-digit losses can still be tolerated.

Even attempts to break this spiral (the Folland Gnat or the Northrop F-5 come to mind) went nowhere. Note that both types were not accepted in their intended role by their respective nations, but could only serve in their training variants.

Today we keep old designs up to date by updating systems, but in many cases the airframe flew first before today's pilots were born. Engineers will rarely work on more than one new frontline combat aircraft design in their whole lifetime because development cycles now stretch over three decades. Compare that to the situation in WWI, when aircraft designs normally became obsolete within one year of their introduction.

Strategic bombing is also no longer part of military doctrine. Instead, the goal is to limit escalation and use highly precise strikes against selected targets. Compare that with the situation in WWII, when the declared goal of bombing was to wear enemy morale down and kill as many people as possible. Back then, collateral damage was a desired side effect, whereas it has become indefensible today. Let's not forget that one of the first (relatively) long-range bombing missions in history targeted a matinée circus performance in Karlsruhe, when heroic French pilots managed to take 120 lives, mostly children and their nannies, on an afternoon raid in June 1916.

To be blunt, classical strategic bombing is as dead as the parrot in that Monty Python sketch.

Answer 4

The platform dropping the bombs becomes less and less important every year. GPS guided bombs can strike a target with the same precision employed from any aircraft flying at 30,000 feet or above. So the type of aircraft doesn't matter much, and it matters less and less as time passes.

The aircraft has simply become a mule to get the bombs to the airspace above the target. Being a dumb mule is a perfect role for an unmanned aircraft, so expect more drones to take over the bombing roles in future decades. Unmanned aircraft will replace both fighters and strategic bombers in the bomber role.