Isegoria

Security was tight when the US Air Force unveiled its new B-21 Raider stealth bomber on December 2, after what happened when the B-2 stealth bomber was revealed:

On November 22, 1988, as armed guards patrolled the tarmac and a Huey helicopter circled overhead, the world got a chance to see the B-2 Spirit — the predecessor of the B-21 in look and function — at the same Palmdale facility.

As with the B-21, spectators were kept at a distance, and only the front of the B-2 could be seen. That was frustrating for those who wanted to see the rear of the B-2, especially the distinctive trailing edges and engine exhausts of the tailless flying-wing bomber, which would give clues to the aircraft’s capabilities and its stealthiness.

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The [Aviation Week] team considered several ideas, including flying a hot-air balloon over the B-2, which was dropped for safety reasons. Eventually they noticed that FAA’s notice to airmen — an alert known as a NOTAM — didn’t restrict flights in the area that were above 1,000 feet.

Aviation Week editor Michael Dornheim and photographer Bill Hartenstein flew a rented Cessna 172 to Palmdale Airport the weekend before the B-2 was unveiled.

“Dornheim performed several circuits and touch-and-gos to allay any potential suspicions from air traffic control, while Hartenstein tried out various telephoto lenses to guarantee he would have the best images of the day,” Aviation Week senior editor Guy Norris wrote this month.

When the big day came, security kept the crowd at least 200 feet from the front of the aircraft, while the low-flying Huey helicopter kept a watchful eye for intruders. But the Cessna circled overhead, unnoticed, as Hartenstein took photo after photo.

When the plane landed, Dornheim and Hartenstein “were just giddy,” Scott said. “They hadn’t got hollered at in any way by ATC [air traffic control] and I told them I hadn’t noticed anyone even looking up!”

The team then raced to meet Thanksgiving week deadlines. Hartenstein’s film was dispatched on an overnight FedEx flight to New York and emerged in the pages of Aviation Week as a beautiful, full-color photo of the B-2 — its trailing edges and exhausts fully visible.

The US is rapidly compensating for the short range of its fighter aircraft, Austin Vernon explains:

China’s response [to the US] is to invest in weapons that keep American planes and ships from getting close to the Chinese mainland. Their strategy is known as anti-access area denial (A2AD). The technological change driving this strategy is cheaper sensors that enable missiles to hit planes and ships hundreds of miles away. Munition effectiveness and logistics intensity dramatically improve. The strategy has an asymmetric advantage since missiles are cheaper than platforms like aircraft carriers.

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Distance is the primary challenge the US military faces in East Asia. The military designed our weapons and supply lines for Europe, where distances are tiny and basing options are numerous. The root cause of the current distress is that carrier strike groups are vulnerable to mass missile attacks and must operate further away from the battle space, causing fighters to lose effectiveness. The two most critical impacted missions are destroying enemy warships and contesting airspace. China can’t invade most of our allies without ships, and ceding the air makes it difficult to kill their ships.

America needs weapons to cover for the deficiency of existing platforms. Opportunities include longer-range missiles, adapting platforms that can operate without carriers, and thwarting missile attacks.

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Long-range stealth bombers are essential for projecting power in East Asia since basing options might be limited, and stealth will be critical to maintaining survivability without persistent fighter cover. The Air Force has gone to great lengths to keep its newest stealth bomber, the B-21, on time and budget. The Air Force Rapid Capability Office manages the program instead of using the traditional procurement process. The project has kept requirements constant, and the design has advanced technology but nothing bleeding edge. For example, the B-21 uses the same engine as the F-35 to save development time and reduce costs. Northrop Grumman also designed the plane to minimize maintenance and sustainment costs. Typically the Air Force and Congress are cutting plane orders due to budget overruns at this point in the process. They are looking at increasing planned B-21 numbers instead. The public rollout happened in December 2022.

It is hard to overstate how important having hundreds of these bombers will be to US power projection in East Asia because they make any Chinese target vulnerable to attack even if carrier aircraft are ineffective.

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Unpowered munitions like gravity bombs and artillery shells are taking a back seat to missiles and rockets as range becomes critical for platform survival. But classical cruise missiles are too expensive for everyday usage. The US and other nations are striving for cheap missiles.

The Guided Multiple Launch Rocket System (GMRLS) rocket that fires from HIMARS and the M270 is a perfect example of the shift. It can hit critical targets far behind enemy lines that are too dangerous for aircraft or too far for tube artillery. Each round costs ~$100,000 – a bargain compared to most cruise missiles that cost millions. The warhead (90 kg) and range (80 km) are smaller than cruise missiles, but the rocket can destroy an ammo depot, troop concentrations, or a headquarters.

Suicide drones or “loitering munitions” are another variation of cheap missiles. The Iranian Shahed-136 costs $20,000-$50,000 and has a 1000+ km range. It sacrifices speed (120 km/h), payload (40 kg), and survivability to achieve cost and range goals. Other drones, like the American Switchblade, serve as squad weapons that improve on mortars.

The Air Force “Gray Wolf” program’s goal was a $100,000 subsonic cruise missile with a 400 km range and a 230 kg warhead. It successfully tested a low-cost engine, and other programs absorbed the follow-on phases. The engine is the Kratos TDI-J85 which can meet the program goals while costing less than $40,000. Kratos already has multiple customers using it for drones and missiles.

Notably, Boeing wants to use the TDI-J85 engine to power its 230 kg JDAM bomb, giving it a 370 km to 750 km range (depending on configuration). The US could lob more QUICKSINK-equipped JDAM cruise missiles in an engagement than the Chinese Navy has vertical launch tubes — all for less than the cost of a frigate. The munition would be 1/10 the price of a Harpoon Block II anti-ship missile with double the range.

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A quirk of the US military is that the Army is responsible for most ground-based missile defense, even on Air Force bases, leading to incentive mismatches. The Navy, which faces an existential threat in anti-ship missiles, has had an automated battle management system in AEGIS for forty years. The Army is trying to field a similar protocol with its Integrated Air and Missile Defense Battle Command System (IBCS) to manage air defense radars and weapons.

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It isn’t hard to shoot down low-end suicide drones, but it can be expensive. Saudi Arabia regularly shoots down Iranian Shaheds with million-dollar air defense missiles. Classic anti-aircraft guns with modern fire control have proven effective in Ukraine, and bullets are much cheaper than drones. Vehicles like the German Gephard are great when defending a wide area because the drones are so slow that vehicles can redeploy to shoot them down.

In East Asia, the US will be defending relatively small positions. One or two Centurion Counter Rocket Artillery Rocket (C-RAM) Gatling guns could probably defend Andersen Air Force Base on Guam.

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Ballistic missiles are a top threat to carriers and US bases in the region. Base hardening, more ammo for existing anti-ballistic missile systems, denying the Chinese intel on ship and aircraft positions, and gaining early warning of Chinese strikes are critical to defending against these weapons.

Bases in Okinawa would be under constant threat from cruise missiles, but only China’s priciest ballistic missiles can reach Guam’s Andersen Air Force Base. Airfields are notoriously hard to take offline. Munitions designed to crater runways only keep a base offline for a few hours. The US has made recent improvements at Andersen AFB, like armoring fuel lines, adding a hardened maintenance hanger, and making fuel bladders available to replace damaged storage tanks.

The worst-case scenario is a surprise attack that kills personnel and destroys aircraft on the ground. The Air Force plans to use smaller dispersal bases to keep the Chinese guessing where the planes are. Investments in better dispersal options and more base hardening (like aircraft shelters for bases on Okinawa) would be beneficial. It would be a win if the Chinese waste their limited amounts of $10-$20 million ballistic missiles to crater a few runways.

The Chinese will find it harder to target Navy ships since they move. Even the fanciest missile is useless if you can’t find the carriers. If a conflict does escalate to space, China will quickly lose its ability to spot the US fleet with satellites. The Navy would expend incredible effort to splash any drones or submarines trying to break into the Pacific to find strike groups. Our carriers could have more freedom of movement than assumed.

The US has invested heavily in ballistic missile defense over the last few decades. There is typically a battery of THAAD missile interceptors deployed in Guam. And the Navy can fire SM-3 and SM-6 missiles at incoming threats. The record for these systems in testing and limited combat use is exemplary, with 90%+ success rates. They are also cheaper than the high-end Chinese missiles they counter. The only issue is that there might not be enough missiles in the theater to counter saturation attacks. Manufacturing more missiles and keeping an adequate number of AEGIS-guided missile ships in East Asia is critical. A credible active defense would force the Chinese to shoot their most valuable missiles in wasteful barrages that drain their missile inventory.

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The AIM-260 air-to-air missile is a fast-track program nearing completion. It nearly doubles the range of the mainstay AIM-120 and is ~20% faster. That allows it to exceed the performance of the Chinese J-15 air-to-air missiles and gives our fighters extra legs. Low-rate production could already be underway.

Having more missiles in the air to handle Chinese mass attacks is also critical. An idea floated by the Pentagon and analysts is to equip bombers with long-range air-to-air missiles, allowing them to act like a missile magazine to support frontline fighters.

The AGM-88 HARM missile is the primary weapon for US aircraft to counter surface-to-air missile batteries. It homes in on their radar signals and forces the enemy to turn off their radar and move or eat a missile. A new extended-range version is faster and can go up to 300 km, allowing US fighters and bombers to counter longer-range surface-to-air missiles.

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Cargo planes loaded with thousands of missiles or QUICKSINK JDAMs free up bombers to hit challenging targets like command and control bunkers or hardened bases and let tankers focus on getting the maximum amount of fighters into the battle to clear the skies.

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Drones can absorb some fighter roles and make them more productive. But the current crop of inexpensive drones that highlight conflicts in Ukraine or Armenia are poorly suited for the Indo-Pacific theater. Most US bases are thousands of kilometers from Taiwan, eliminating smaller drones and quadcopters. Slow drones like TB-2 or Predator are not survivable in contested airspace. Drones must be expendable or much more capable to add value to US power projection.

One example is the RQ-180. The Air Force has never acknowledged its existence, but the rumors and evidence are strong that it exists. It replaces the Global Hawk in the high altitude, theater-wide surveillance mission. The Global Hawk has close to zero survivability and can’t function against near-peer threats. The RQ-180 is a flying wing like the B-2 and is stealthy, allowing it to operate in contested airspace. It likely costs hundreds of millions per copy, but small drones can’t replace it.

The Scan Eagle and its successor, the RQ-21 Blackjack, are current “attritable” surveillance drones. They are capable aircraft with high-end sensors, the ability to laser designate targets, and 16 hours of loiter time. The Navy and Marines have hundreds but want to replace them. Newer drones in this class have vertical take-off and landing (VTOL) capability, allowing them to ditch expensive launching/landing systems. Software flies the drones and soldiers only input waypoints. The competition is fierce, with AeroEnvironment’s Jump 20 and Shield AI’s V-Bat as examples. These drones are more capable than the RQ-21 at a fraction of the acquisition and operating cost, costing less than $1 million per unit even at low rate production. A limitation is they can’t stray more than ~150 km from the base station. Some obvious solutions are to use StarLink, drone relays, or autonomous software that can broadcast findings over the tactical data net. Much of the cost is in sensors, less expensive ones would make the drones more expendable. Production could ramp up fast because scrappy companies are the prime contractors.

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Tankers and aerial refueling are the backbones of the US Air Force’s power projection, especially in East Asia. They are nearly as critical for the Navy. Tanker vulnerability is one reason why 24/7 combat air patrols over Taiwan from bases or carriers further than Guam are challenging. Fueling the patrols would stretch the tanker force thin while exposing them to Chinese attack. The Chinese Air Force could “lose the battle, but win the war” by bull rushing the few fighters on station, running them out of missiles, then splashing the string of valuable tankers leading back to US bases.

When the F-22 design team struggled to meet its weight and unit-cost goals, it decided to step back and open up the design to more fundamental changes:

“After a bloody debate, we agreed to trash the current design and start over,” says Mullin. “Over that weekend, we brought in a new director of design engineering, Dick Cantrell, flew in people, and started a ninety-day fire drill. Work started on Monday 13 July. That date marks one of the most creative periods of conceptual design for any fighter aircraft. We looked at different inlets, different wings, and different tail combinations. One configuration had two big butterfly tails and looked somewhat like the F-117, though people did not know that since the F-117 was still highly classified. The configuration search was wide open, but the biggest single change that resulted from it was to go with diamond-shaped wings.”

The concentrated configuration search began with a slew of possible designs. The search complicates the numbering scheme considerably, as diamond wings, twin tails (two tails instead of four), various inlet shapes, and various forebody shapes were all considered and reconsidered simultaneously in the summer of 1987.

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“The fundamental reason for going to a diamond wing was that it provided the lightest configuration and gave us the best structural efficiency and all the control power we needed for maneuvering,” Mullin explains. “The biggest consideration was its light weight. Weight drove the decision.”

“A diamond wing has more square feet of surface area, but is more structurally efficient,” adds Renshaw. “The longer root chord provides a more distributed load path through the fuselage. Multiple bulkheads carry the bending loads. The design provides more opportunity to space the bulkheads around the internal equipment. It also provides more fuel volume.”

“The structural engineers wanted a diamond wing because it provides a larger root chord, which carries bending moments better,” Hardy notes. “The aerodynamicists wanted a trapezoidal wing because it provides more aspect ratio, which is good for aerodynamics. Dick Heppe, the president of Lockheed California Company, made the final decision, and he was right. The aerodynamics were not all that different, but the structure and weights were significantly better. So we went to a diamond shape. The big root chord, though, moved the tails back. Eventually we even had to notch the wing for the front of the tails. If the tails moved farther back, they would fall off the airplane.”

Once the wings were set with Configuration 614, subsequent configurations dealt with the tail arrangement. “We spent a lot of wind tunnel time looking at the tails,” recalls Lou Bangert, the chief engineer for engine integration from Lockheed. “From late 1987 to early 1988, we were engaged in what we called ‘the great tail chase.’ We knew we would have four tails, but where they would go was a big deal. A small change in location often made a huge difference. We had to look at performance effects, stealth effects, stability and control, and drag at the same time. The tail arrangement and aft end design were important design considerations for all of these effects.”

Wind tunnel results showed an ultra-sensitive relationship between the placement of the vertical tails and the design of the forward fuselage. The interactions could not be predicted accurately by analysis or by computational fluid dynamics. The airflow over the forebody at certain angles of attack affects the control power exerted by the twin rudders on the vertical tails. Getting the airflow right was critical.

The cant and sweep angles of the vertical tails could not be altered too much because such changes increased radar signature. In finding a suitable arrangement, the control system designers were constrained by the radar signature requirements to moving the tail locations laterally or longitudinally and to shrinking or enlarging them while holding the shape essentially constant. By the end of the dem/val phase, the team had accumulated around 20,000 hours in the wind tunnel. A lot of this time was devoted to tail placement studies.

The basic challenge of designing the F-22 was to pack stealth, supercruise, highly integrated avionics, and agility into an airplane with an operating range that bettered the F-15, the aircraft it was to replace:

“One problem we typically face when trying to stuff everything inside an airplane is that everything wants to be at the center of gravity,” Hardy explains. “The weapons want to be at the center of gravity so that when they drop, the airplane doesn’t change its stability modes. The main landing gear wants to be right behind the center of gravity so the airplane doesn’t fall on its tail and so it can rotate fairly easily for takeoffs. The fuel volume wants to be at the center of gravity, so the center of gravity doesn’t shift as the fuel tanks empty. Having the center of gravity move as fuel burns reduces stability and control. We also had to hide the engine face for stealth reasons. So, these huge ducts had to run right through the middle of real estate that we wanted to use for everything else. The design complexities result in specialized groups of engineers arguing for space in the airplane. That was the basic situation from 1986 through 1988.”