Washington(CNN) The US military gave North Korean leader Kim Jong Un a rare sneak peek at its fighter jet of the future this week when four F-35 Joint Strike Fighters equipped with a full payload of live bombs and missiles conducted a training flight over the Korean peninsula.
Along with its fifth-generation counterpart -- the F-22 Raptor -- the F-35 is widely considered the most advanced fighter jet in the skies but the US military is planning to upgrade both aircraft with even more firepower and combat capability amid a growing demand for US air power around the world.
The F-22 and F-35 have long been touted as the future of US aerial dominance -- the expectation being that the Raptors's air-to-air combat capabilities will work in concert with the multi-role F-35's advanced long-range sensors to maintain an advantage over emerging competition from foreign rivals like China and Russia.
Both aircraft have flown training missions over the Korean peninsula in recent months despite ongoing efforts to expand their combat capabilities.
Cloaked with the world's most advanced stealth coating, the F-22 and F-35 would likely be called upon to lead a potential air campaign against North Korea should the situation escalate to the point of using military force.
While the North Korean military maintains capable anti-air weaponry, their radar systems would be unable to detect the stealth fighters before a strike on those defensive systems.
While the F-22 Raptor has been involved in combat missions since 2014, the Air Force is planning to equip the fifth-generation aircraft with new missiles, upgraded sensors and perform key maintenance on its special stealth coating.
Scout Warrior was first to report the planned F-22 upgrades.
The Air Force is also in the early stages of improving the F-22's software and on-board sensors so that it will be able to seamlessly connect and share information with F-35 aircraft.
But while the F-22 is set for a face-lift to maintain its competitive edge, the Pentagon could decide against upgrading the F-35s that have already been delivered once the program's latest weapons and software capabilities are fully developed in early 2018.
In the U.S. Air Force fleet
The first versions of this long-range heavy bomber flew in 1954. A total of 744 were built, the last of those in 1962. The Air Force maintains 58 B-52s in the active force and 18 in the Reserve. A single B-52 can carry 70,000 pounds of mixed munitions, including bombs, missiles and mines. The eight-engine jets have a range of 8,800 miles.
A C-130J Super Hercules from the 37th Airlift Squadron flies over Normandy, France, June 3, 2015. First delivered to the Air Force in 1956, the C-130 remains one of the service's most important airlift platforms. More than 140 are still in active units, with more than 180 in the National Guard and a hundred more in the Reserve. The C-130 is powered by four turboprop engines.
The AC-130H Spectre and the AC-130U Spooky gunships are designed for close air support, air interdiction and force protection. Armaments on the Spectre include 40mm and 105mm cannons. The Spooky adds a 25mm Gatling gun.
The twin-engine F-22 stealth fighter, flown by a single pilot and armed with a 20mm cannon, heat-seeking missiles, radar-guided missiles and radar-guided bombs, can perform both air-to-air and air-to-ground missions. The service has 183 of the Raptors, which went operational in 2005.
The single-engine F-35A is the Air Force's eventual replacement for the F-16 and the A-10. The supersonic jets, which will be able to conduct air-to-air and air-to-ground attacks, are just beginning to enter the Air Force fleet. Here, an F-35 Lightning II from the 34th Fighter Squadron at Hill Air Force Base, Utah, flys at Royal Air Force Lakenheath, England, April 15, 2017.
The four-engine B-2 heavy bomber has stealth properties that make it hard to detect on radar. Flown by a crew of two, it has an unrefueled range of 6,000 miles and can deliver both conventional and nuclear bombs. Twenty B-2s are in the active inventory. They joined the fleet in 1997.
The four-engine jet can fly at 900 mph and carry the largest payload of bombs and missiles in the Air Force inventory. The Air Force has 62 B-1Bs in the fleet.
The F-15 Eagle, the Air Force's main air superiority fighter, became operational in 1975. With a crew of one or two, depending on the model, the twin-engine jets are armed with a 20mm cannon along with Sidewinder or AMRAAM missiles. The Air Force lists 249 F-15 Eagles in its inventory.
The Strike Eagle is a version of the air superiority fighter adapted to perform ground-strike missions. With a crew of two, the twin-jet can carry and deploy most weapons in the Air Force inventory and operate in any weather. The F-15E was first delivered in 1988. The Air Force lists 219 in its fleet.
The A-10 Thunderbolt jets, nicknamed "Warthogs," are specially designed for close air support of ground forces. Key to their armaments is a 30mm Gatling gun. The pilot is protected from ground fire by titanium armor, and the plane's fuel cells are self-sealing in case of puncture.
The RC-135U Combat Sent, based at Offutt Air Force Base, Nebraska, provides strategic electronic reconnaissance information to the president, secretary of defense, Department of Defense leaders and theater commanders.
An F-15 Eagle takes off from the Andersen Air Force Base, Guam, flight line as two E-3 Sentries are seen in the background.
A 21st Tactical Air Support Squadron OV-10 Bronco aircraft fires white phosphorus rockets to mark a target for an air strike during tactical air control training.
An A-29 Super Tucano taxis on the flightline during its first arrival, Sept. 26, 2014, at Moody Air Force Base, Georgia. Afghan Air Force pilots trained on the planes that will be used in air-to-ground attack missions in Afghanistan.
The four-engine KC-135 joined the Air Force fleet in 1956 as both a tanker and cargo jet. It can carry up to 200,000 pounds of fuel and 83,000 pounds of cargo and passengers in a deck above the refueling system. More than 400 of the KC-135s are flown by active, Air Guard and Reserve units.
The single-engine jet is a mainstay of the Air Force combat fleet. It can perform both air-to-air and air-to-ground missions with its 20mm cannon and ability to carry missiles and bombs on external pods. More than 1,000 F-16s are in the Air Force inventory.
The four-engine jet joined the Air Force fleet in 1993 with a primary mission of troop and cargo transport. Each plane can carry up to 102 troops or 170,900 pounds of cargo. The Air Force has 187 C-17s on active duty, 12 in the Air National Guard and 14 in the Reserve.
The C-5, with a wingspan of 222 feet, a length of 247 feet and a height of 65 feet, is the largest plane in the Air Force inventory and one of the largest aircraft in the world. The first versions of the four-engine jet joined the force in 1970. The Air Force expects to have 52 versions of the latest model, the C-5M, in the fleet by 2017.
The Osprey is a tiltrotor aircraft that combines vertical takeoff, hover and landing qualities of a helicopter with the normal flight characteristics of a turboprop aircraft, according to the Air Force. It is used to move troops in and out of operations as well as resupply units in the field. The Air Force has 33 Ospreys in inventory.
AWACS stands for airborne warning and control system. This four-engine jet, based on a Boeing 707 platform, monitors and manages battle space with its huge rotating radar dome. The planes have a flight crew of four supporting 13 to 19 specialists and controllers giving direction to units around the battle space. The Air Force has 32 E-3s in inventory.
Based on the DC-10 passenger jet, the triple-engine KC-10 is a gas station in the sky with the ability to carry 75 people and 170,000 pounds of cargo. In its six tanks, the KC-10 can carry up to 356,000 pounds of fuel and dispense it while airborne. The Air Force has 59 KC-10s on active duty.
The twin-engine jet trainer, used by the Air Force to prepare pilots for the F-15E Strike Eagle, F-15C Eagle, F-16 Fighting Falcon, B-1B Lancer, A-10 Thunderbolt and F-22 Raptor, first flew in 1959. Almost 550 are in the active force.
The single-engine, single-pilot U-2 is used for high-altitude reconnaissance and surveillance. Flying at altitudes around 70,000 feet, pilots must wear pressure suits like those worn by astronauts. The first U-2 was flown in 1955. The planes were used on missions over the Soviet Union during the Cold War, flying too high to be reached by any adversary. The Air Force has 33 U-2s in its active inventory.
The four-engine WC-135 is used to fly through airspace to detect the residue of nuclear blasts. "The aircraft is equipped with external flow-through devices to collect particulates on filter paper and a compressor system for whole air samples collected in holding spheres," the Air Force says. It has two of these jets in the active force.
Delays during the F-35's development stage caused the aircraft's manufacturer Lockheed Martin to initially deliver 108 aircraft equipped with less advanced software and weapons compatibility. The plan had been to retrofit those jets with updated systems to maximize the F-35's combat capability.
But as the F-35 program prepares to ramp-up production with more than 900 aircraft expected for delivery over the next five years, the Pentagon could choose not to update its current inventory of 108 planes as a cost saving measure, according to recent comments by Vice Adm. Matt Winter, the F-35's program executive.
If current F-35s are not retrofitted with the next round of upgrades -- which includes more weapons, stealth modifications and added sensor fusion capability -- it would mean that they will never achieve their maximum combat potential.
"The US is planning to buy more than 2,300 F-35s and does not need all of them to be combat capable," according to Joe Dellavedova, a spokesperson for the F-35 Joint Program Office.
"Each service will be able to decide whether they want all their planes to have full capability or if some can be used for training or other purposes," he said, adding that the money saved could be used toward other initiatives.
But critics of the F-35 program's "buy before you fly" mentality told CNN that the need to upgrade aircraft that have already been delivered points to a larger issue with the way new weapons systems are developed and purchased.
"This is an object lesson in why we shouldn't buy any weapons system in quantity before it is tested," said Dan Grazier of the Project on Government Oversight. "If we are talking about the 108 planes bought in the earliest lot that means the most expensive aircraft that were purchased will never be fully ready for combat."
The F-35 is already the most expensive weapons system in history with costs exceeding $400 billion over nearly 20 years of testing and development.
The plane with a "brain"
Often called a "flying computer," the F-35 requires significantly more coding than the F-22 to operate its high-tech sensors and radar meaning upgrades could cost millions of dollars per plane.
President Donald Trump has taken a personal interest in the F-35 program, slamming the costs as "out of control" and then getting involved in the Pentagon's contract negotiations with Lockheed Martin. He took credit for generating $700 million in savings in the $8.5 billion contract for the latest batch of F-35 fighters.
The Air Force's version of the F-35 fighter jet was declared combat ready last year, and F-35s have now deployed to Japan and Europe.
The F-35B Marine Corps variant was declared combat-ready in 2015, and the F-35C Nary variant is supposed to be combat operational next year.
But the jets that have already been delivered would require several modifications to achieve the next planned stage of combat standards as they currently employ a less sophisticated software and hardware systems than those currently being developed.
If the Pentagon opts not to upgrade the software on the F-35s that have already been delivered, those aircraft would likely be designated for training purposes rather than made available in the military's already shrinking inventory combat-ready planes.
The Pentagon is hoping to expedite the software modernization process for both the F-22 and the F-35 by tapping into the expertise of commercial Silicon Valley companies to cooperate with traditional defense contractors like Lockheed and Boeing.
"We want to deliver a product to market faster than the competitor," said Louis Duncan, head of modernization for the Air Force's F-22 office. "Here our competitor is the threat."
F-22 upgrades
The F-22 is already known for speed and stealth -- able to travel at twice the speed of sound and hard to spot on radar.
In the U.S. Air Force fleet
The first versions of this long-range heavy bomber flew in 1954. A total of 744 were built, the last of those in 1962. The Air Force maintains 58 B-52s in the active force and 18 in the Reserve. A single B-52 can carry 70,000 pounds of mixed munitions, including bombs, missiles and mines. The eight-engine jets have a range of 8,800 miles.
A C-130J Super Hercules from the 37th Airlift Squadron flies over Normandy, France, June 3, 2015. First delivered to the Air Force in 1956, the C-130 remains one of the service's most important airlift platforms. More than 140 are still in active units, with more than 180 in the National Guard and a hundred more in the Reserve. The C-130 is powered by four turboprop engines.
The AC-130H Spectre and the AC-130U Spooky gunships are designed for close air support, air interdiction and force protection. Armaments on the Spectre include 40mm and 105mm cannons. The Spooky adds a 25mm Gatling gun.
The twin-engine F-22 stealth fighter, flown by a single pilot and armed with a 20mm cannon, heat-seeking missiles, radar-guided missiles and radar-guided bombs, can perform both air-to-air and air-to-ground missions. The service has 183 of the Raptors, which went operational in 2005.
The single-engine F-35A is the Air Force's eventual replacement for the F-16 and the A-10. The supersonic jets, which will be able to conduct air-to-air and air-to-ground attacks, are just beginning to enter the Air Force fleet. Here, an F-35 Lightning II from the 34th Fighter Squadron at Hill Air Force Base, Utah, flys at Royal Air Force Lakenheath, England, April 15, 2017.
The four-engine B-2 heavy bomber has stealth properties that make it hard to detect on radar. Flown by a crew of two, it has an unrefueled range of 6,000 miles and can deliver both conventional and nuclear bombs. Twenty B-2s are in the active inventory. They joined the fleet in 1997.
The four-engine jet can fly at 900 mph and carry the largest payload of bombs and missiles in the Air Force inventory. The Air Force has 62 B-1Bs in the fleet.
The F-15 Eagle, the Air Force's main air superiority fighter, became operational in 1975. With a crew of one or two, depending on the model, the twin-engine jets are armed with a 20mm cannon along with Sidewinder or AMRAAM missiles. The Air Force lists 249 F-15 Eagles in its inventory.
The Strike Eagle is a version of the air superiority fighter adapted to perform ground-strike missions. With a crew of two, the twin-jet can carry and deploy most weapons in the Air Force inventory and operate in any weather. The F-15E was first delivered in 1988. The Air Force lists 219 in its fleet.
The A-10 Thunderbolt jets, nicknamed "Warthogs," are specially designed for close air support of ground forces. Key to their armaments is a 30mm Gatling gun. The pilot is protected from ground fire by titanium armor, and the plane's fuel cells are self-sealing in case of puncture.
The RC-135U Combat Sent, based at Offutt Air Force Base, Nebraska, provides strategic electronic reconnaissance information to the president, secretary of defense, Department of Defense leaders and theater commanders.
An F-15 Eagle takes off from the Andersen Air Force Base, Guam, flight line as two E-3 Sentries are seen in the background.
A 21st Tactical Air Support Squadron OV-10 Bronco aircraft fires white phosphorus rockets to mark a target for an air strike during tactical air control training.
An A-29 Super Tucano taxis on the flightline during its first arrival, Sept. 26, 2014, at Moody Air Force Base, Georgia. Afghan Air Force pilots trained on the planes that will be used in air-to-ground attack missions in Afghanistan.
The four-engine KC-135 joined the Air Force fleet in 1956 as both a tanker and cargo jet. It can carry up to 200,000 pounds of fuel and 83,000 pounds of cargo and passengers in a deck above the refueling system. More than 400 of the KC-135s are flown by active, Air Guard and Reserve units.
The single-engine jet is a mainstay of the Air Force combat fleet. It can perform both air-to-air and air-to-ground missions with its 20mm cannon and ability to carry missiles and bombs on external pods. More than 1,000 F-16s are in the Air Force inventory.
The four-engine jet joined the Air Force fleet in 1993 with a primary mission of troop and cargo transport. Each plane can carry up to 102 troops or 170,900 pounds of cargo. The Air Force has 187 C-17s on active duty, 12 in the Air National Guard and 14 in the Reserve.
The C-5, with a wingspan of 222 feet, a length of 247 feet and a height of 65 feet, is the largest plane in the Air Force inventory and one of the largest aircraft in the world. The first versions of the four-engine jet joined the force in 1970. The Air Force expects to have 52 versions of the latest model, the C-5M, in the fleet by 2017.
The Osprey is a tiltrotor aircraft that combines vertical takeoff, hover and landing qualities of a helicopter with the normal flight characteristics of a turboprop aircraft, according to the Air Force. It is used to move troops in and out of operations as well as resupply units in the field. The Air Force has 33 Ospreys in inventory.
AWACS stands for airborne warning and control system. This four-engine jet, based on a Boeing 707 platform, monitors and manages battle space with its huge rotating radar dome. The planes have a flight crew of four supporting 13 to 19 specialists and controllers giving direction to units around the battle space. The Air Force has 32 E-3s in inventory.
Based on the DC-10 passenger jet, the triple-engine KC-10 is a gas station in the sky with the ability to carry 75 people and 170,000 pounds of cargo. In its six tanks, the KC-10 can carry up to 356,000 pounds of fuel and dispense it while airborne. The Air Force has 59 KC-10s on active duty.
The twin-engine jet trainer, used by the Air Force to prepare pilots for the F-15E Strike Eagle, F-15C Eagle, F-16 Fighting Falcon, B-1B Lancer, A-10 Thunderbolt and F-22 Raptor, first flew in 1959. Almost 550 are in the active force.
The single-engine, single-pilot U-2 is used for high-altitude reconnaissance and surveillance. Flying at altitudes around 70,000 feet, pilots must wear pressure suits like those worn by astronauts. The first U-2 was flown in 1955. The planes were used on missions over the Soviet Union during the Cold War, flying too high to be reached by any adversary. The Air Force has 33 U-2s in its active inventory.
The four-engine WC-135 is used to fly through airspace to detect the residue of nuclear blasts. "The aircraft is equipped with external flow-through devices to collect particulates on filter paper and a compressor system for whole air samples collected in holding spheres," the Air Force says. It has two of these jets in the active force.
But the goal of these improvements is maximize the F-22's air combat power by maintaining the "first look, first shot, first kill" capability that makes it one of the most lethal air-to-air fighter jets in the US fleet, according to Lockheed Martin, the aircraft's manufacturer that is tasked with implementing the modifications.
"These upgrades will help pilots see further, take the shot more quickly and get the kill," according to Ken Merchant, vice president of Lockheed Martin's F-22 Program.
Col. Darien Hammett of the Air Force's F-22 office put it simply when asked why these upgrades are necessary: "The F-22 has no equal and that's why we are modernizing, to keep it that way."
The Air Force said it is still negotiating exact costs for this wave of additions to the F-22 but noted that the program's total direct and indirect costs have been stable even with added capabilities and higher usage as it continues to fly more missions.
While F-22's airframe is designed to last until 2060, periodical maintenance to its stealth coating is needed to ensure the jet performs with maximum effectiveness without being spotted on radar, according to Lockheed Martin.
Lockheed Martin is currently working to repair the special coating on several F-22s due to heightened demand for stealth capability amid increasing deployments and on-going combat operations.
By 2019, the Air Force and Lockheed Martin also hope to upgrade the F-22 to carry advanced AIM-120D and AIM-9X Air-to-Air missiles as well as enhanced air-to-surface target location capabilities.
What will the upgrades do?
The F-22 Raptor began taking part in combat missions against ISIS in September 2014 after years of cost overruns and mechanical issues.
It was originally designed to complement the fifth-generation F-35 Joint Strike Fighter and replace other attack aircraft in the US military's arsenal.
But the F-35 is only now beginning to be deployed and is not battle tested like the F-22.
The Raptor is better at air-to-air missions than the F-35 which has superior air-to-ground capability, according to the F-35 website.
Both planes have had their own widely reported sets of development challenges.
But due to the F-22 program's early issues, the Air Force acquired only 188 of them from aerospace maker Lockheed Martin and doesn't plan to have any more produced.
Today, the Air Force has 187 of the fighters after one crashed in 2010, killing the pilot. A subsequent report by the Pentagon watchdog found the Air Force initially blamed the crash on pilot error when in fact a mechanical error was at fault.
Despite past challenges, "the F-22 cannot be matched by any known or projected fighter aircraft," said the Air Force's fact sheet for the Raptor, each of which costs about $143 million.
The F-22 has earned its stripes fighting ISIS during the air campaign in Syria where its primary role has been to protect other military resources by taking down enemy aircraft if they threaten the US assets.
"It has also acted as a bit of a quarterback ... helping lead older fourth-generation aircraft into the fight and showing them where the threat is," according to Merchant, who said the F-22's combination of stealth, radar and sensor technology allows it to see further into the fight than less advanced planes.
The Air Force hopes to further enhance the F-22's ability to integrate with older aircraft in the fleet by 2021 -- upgrading its current verbal-based communication platform with a datalink system that would allow the aircraft to transmit information to other pilots automatically.
"We've learned that the F-22 is a big vacuum cleaner for data and it would be valuable to share that data with other aircraft," said Merchant, whose team is working to develop that capability.
Moving forward, the Air Force will be faced with the challenge of upgrading the F-22's software and on-board sensors to address future threats, according to Lockheed Martin, who are in the early stages of designing these new platforms with the goal of enabling the F-22 and F-35 to better connect with one another.
That immediate exchange of information -- such as targeting data -- is also expected to give the US an advantage against a variety of emerging future threats around the world.
In the short term, upgrades to the F-22's weapons package and stealth capabilities will enhance its effectiveness within on-going combat operations, according to Lockheed Martin.
Already in the fight
While the F-22 is currently engaged in the air campaign against ISIS, it has also been deployed in support of NATO partners to counter potential Russian aggression and has been used to intercept foreign aircraft flying too close to US borders.
It can also be used as an "instrument of national power," according to Merchant, who said the strategic placement of F-22s can send a similar message as a traditional show of force executed by an aircraft carrier.
"It is changing the way you show your sword," Merchant said, noting that he could see the US military using joint deployments of F-35s and F-22s to make a statement in other parts of the world.
And as tensions rise between the US and North Korea, the F-22 would serve an important role in a potential military strike option.
The F-22 stealth fighters would be a key part of any US pre-emptive strike on North Korea designed to neutralize the country's defensive and counterstrike capabilities, Jerry Hendrix, a retired Navy captain and senior fellow at the Center for a New American Security, told CNN earlier this month.
Countering North Korea's relatively formidable surface-to-air missile defense capabilities, stealth American F-22s, F-35 Joint Strike fighters and B-2 bombers would likely lead a joint air campaign with the help of Japanese and South Korean F-15 or F-16 fighters, he said.