(CNN) The unmistakable roar of the A-10's powerful engines echoed throughout Arlington National Cemetery this month as four aircraft saluted retired Col. Avery Kay for the last time with a rare flyover of the historic burial site.

Kay, 96, died on October 29 and was buried with full military honors.

A highly decorated navigator who led some of the most dangerous bombing raids against Germany during World War II, Kay was also credited with launching the concept of the A-10 Thunderbolt, better known as the Warthog.

Despite lacking the air-to-air combat ability of the F-15 Eagle and the high-tech stealth capabilities of the F-22 Raptor, the U.S. Air Force still uses the A-10 to support ground forces in close combat more than 40 years after its first flight in 1975.

But if it hadn't been for Kay, this iconic plane may have been grounded before ever seeing battle.

As an adviser to then-Air Force Chief of Staff John McConnell in the 1960s, Kay put his professional reputation on the line and led the fight to create a plane specifically designed to assist troops on the ground.

"Without Col. Kay, there would be no A-10 today," said Pierre Sprey, a former Pentagon official who helped Kay design the plane despite objections from many in the Air Force leadership.

At the time, the issue of close air support was at the center of a contentious budget debate between the Army and the Air Force over how to divide funding for fixed-wing planes and helicopters.

Army leaders often argued it took too long for the Air Force to respond to calls for assistance, specifically during the Vietnam War, and demanded control of budget funds to develop their own heavily armed helicopter that could better meet their needs.

The Air Force, however, wanted control over the development of all fixed-wing aircraft and insisted that any type of plane could perform close air support.

But in reality, the Air Force's top generals had little interest in dedicating budget dollars for improving support for ground troops, as they preferred planes that could carry out bombing missions deep in enemy territory.

Spearheading negotiations between the two service branches, Kay proposed an agreement under which the Army would relinquish control of the development of all fixed-wing aircraft as long as the Air Force fulfilled its promise to build a plane that was able to provide the air support that was lacking during Vietnam.

Using the very real threat of the Army's plan to build a helicopter to take over Air Force close support, Kay convinced McConnell that if the Army got its funding approved, he would go down in Air Force history as the chief that lost the close support mission and the money that goes along with it.

To counter the Army's proposal, Kay pitched a plan to build an airplane dedicated to the close support missions that would be cheaper and more effective than any helicopter.

McConnell approved the plan, but Kay quickly realized that he would have to circumvent the normal chain of command to fulfill his promise to the Army, as many of the Air Force's top generals still lacked interest in spending budget dollars on this cause.

Rather than approaching the Air Staff and Tactical command offices, which normally facilitate the building of new planes, Kay reached out to Sprey, who was working for the defense secretary, to help make his plan for the A-10 become a reality.

"What he did at this point is he put his career on the line," Sprey recalled.

Together, Kay and Sprey worked in secret to develop an aircraft that could cover ground troops from an enemy advance, buying time for grunts to regroup or get out with an aerial weapons strike.

"The entire A-10 community is basically due to his guts and his integrity," said Sprey, now an adviser for the Project on Government Oversight. "If anyone deserves the title of 'father of the A-10,' Col. Kay definitely does."

Photos: In the U.S. Air Force fleet B-52 Stratofortress – 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. Hide Caption 1 of 24 Photos: In the U.S. Air Force fleet C-130 Hercules transport – 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. Hide Caption 2 of 24 Photos: In the U.S. Air Force fleet AC-130 gunships – 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. Hide Caption 3 of 24 Photos: In the U.S. Air Force fleet F-22 Raptor – 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. Hide Caption 4 of 24 Photos: In the U.S. Air Force fleet 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. Hide Caption 5 of 24 Photos: In the U.S. Air Force fleet B-2 Spirit bomber – 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. Hide Caption 6 of 24 Photos: In the U.S. Air Force fleet B-1B Lancer bomber – 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. Hide Caption 7 of 24 Photos: In the U.S. Air Force fleet F-15 Eagle – 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. Hide Caption 8 of 24 Photos: In the U.S. Air Force fleet F-15E Strike Eagle – 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. Hide Caption 9 of 24 Photos: In the U.S. Air Force fleet A-10 Thunderbolt – 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. Hide Caption 10 of 24 Photos: In the U.S. Air Force fleet RC-135U – 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. Hide Caption 11 of 24 Photos: In the U.S. Air Force fleet 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. Hide Caption 12 of 24 Photos: In the U.S. Air Force fleet OV-10 Bronco – 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. Hide Caption 13 of 24 Photos: In the U.S. Air Force fleet A-29 Super Tucano – 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. Hide Caption 14 of 24 Photos: In the U.S. Air Force fleet KC-135 Stratotanker – 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. Hide Caption 15 of 24 Photos: In the U.S. Air Force fleet F-16 Fighting Falcon – 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. Hide Caption 16 of 24 Photos: In the U.S. Air Force fleet C-17 Globemaster transport – 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. Hide Caption 17 of 24 Photos: In the U.S. Air Force fleet C-5 Galaxy transport – 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. Hide Caption 18 of 24 Photos: In the U.S. Air Force fleet CV-22 Osprey – 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. Hide Caption 19 of 24 Photos: In the U.S. Air Force fleet E-3 Sentry AWACS – 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. Hide Caption 20 of 24 Photos: In the U.S. Air Force fleet KC-10 Extender – 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. Hide Caption 21 of 24 Photos: In the U.S. Air Force fleet T-38 Talon – 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. Hide Caption 22 of 24 Photos: In the U.S. Air Force fleet U-2 – 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. Hide Caption 23 of 24 Photos: In the U.S. Air Force fleet WC-135 Constant Phoenix – 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. Hide Caption 24 of 24

The A-10 has saved the lives of countless troops during each of the last four wars fought by the United States and is used today in the fight against ISIS in Iraq and Syria.

But today, the war bird is fighting a similar funding battle to the one Kay faced in the 1960s, surviving year to year because of the strain on Air Force funds resulting from budget sequestration.

Pentagon leadership thinks the A-10 is too expensive to maintain under the current spending limits when other aircraft can fill similar roles. And several lawmakers involved with military allocations believe other expensive undertakings -- such as finding ways to neutralize the deadly improvised explosive devices U.S. soldiers face in the Middle East -- are higher funding priorities.

Looming over the debate is the sleek, super-high-tech, massively expensive F-35 Lightning, which was expected to replace the A-10 as the Air Force's primary close air support aircraft. Despite its potential, the F-35 has been riddled with setbacks and is still a long way from deployment.

In January, Gen. David Goldfein, the Air Force's vice chief of staff, told Defense News the rise of ISIS and the U.S. air campaign to fight the terror group has prompted the service to reconsider plans to retire the A-10.

"When we made the decision on retiring the A-10, we made those decisions prior to ISIL, we were not in Iraq, we were coming out of Afghanistan to a large extent, we didn't have a resurgent Russia," Goldfein said in an interview on "Defense News With Vago Muradian."

Goldfein's office confirmed the general's remarks to CNN.

The retirement of the A-10 was not part of the Pentagon budget request submitted to Congress in February, but the plane's long-term future remains in question.