Since Russia's invasion of Ukraine, neither side has achieved complete air superiority, surprising analysts and officials who believed that Russia's superior air force would overwhelm the Ukrainians.
The Ukrainian air force and air defenses are still fighting Russian airpower five months later.
Observers have recorded the loss of 36 Russian and 35 Ukrainian combat aircraft as of late July, but Russia appears to have narrowed the scope of its operations.
The reported numbers show the intensity of the aerial struggle.
Both of the countries that were part of the Soviet Union have the same military aircraft inventories.
The most popular fighter in Ukraine prior to February 24 was the MiG-29, which was adopted by the Soviets.
Air-to-air combat is what the MiG-29 is designed for. The ceiling is just under 60,000 feet and it has a maximum speed of 1,500 mph. It has a 30mm autocannon with 150 rounds and can carry up to 8000 pounds of ordnance.
The Soviets adopted the Su 27 in 1985. The Soviet fighter had fly-by-wire controls.
The Su-27 is an air-superiority fighter that can conduct strikes and has a top speed of 1,500 mph. It has 10 hardpoints that allow it to carry over 9,700 pounds of ordnance.
Russia andUkraine are attacking each other with the same aircraft.
The Su 24 is a variable-sweep wing attack aircraft. It has a top speed of about 1,000 mph with a ceiling of about 36,000 feet and can carry over 17,000 pounds of weaponry. The cannon has a 23mm barrel and 500 rounds.
In 1993 the Su 25 was adopted. It has a top speed of 600 mph and a ceiling of 22,000 feet and is intended for close air support.
In addition to a 30mm dual-barrel cannon with 250 rounds, the Su-25 has 10 hardpoints and can carry over 9000 pounds of weaponry, including missiles, rockets, guided and unguided bombs. There are steel and titanium plates ranging from 6mm to 25mm thick around the cockpit, parts of the fuselage, and wings.
The Su-25 is fast, low-flying and has been compared to the US Air Force's vaunted A-10).
The inventory of flyable combat aircraft in Ukraine was about 37 MiG-29s, 34 Su 27s, 31 Su 25s, and 14 Su 24Ms.
Early in the war, some of the Ukrainian aircraft were active. When the Russians tried to seize Hostomel Airport, it was supported by its Su 24s and MiG 29s. Several Russian aircraft and missiles were likely trying to intercept Ukrainian Su 27s around Kiev.
Russian air defense systems have taken a toll. A total of 35 Ukrainian combat aircraft have been destroyed.
It is difficult for ground-based anti-aircraft systems to distinguish friendly jets from Russian ones.
Despite the losses, Ukraine may have more operational aircraft now than it did at the beginning of the war, as spare parts donated by NATO have allowed it to airframe refits that were in storage
There are still Ukrainian fighters on the frontline. Ukrainian Su-23s and Su-26s have been spotted near combat zones, while one of its MiGs shot down a Russian Su-35 on May 27. Ukrainian Su 27s have been seen bombing Snake Island, and may have been involved in strikes on Russian oil facilities.
Since the beginning of the war, Russia's air operations have increased. The jets are usually in pairs or in teams of four.
Russia's Su-25s are the most likely to be seen. They are often engaged by Ukrainian air defense because they have to fly so low. More than a dozen Russian Su-25s have been shot down and more have been damaged.
Russia's air force is different from that of Ukraine's air force due to the fact that it is modernized. The Su-30, Su-35, and Su-34 were all developed from the Su-27 frame.
The Su 30 and Su 35 were adopted in 1996. Air-superiority fighters can perform other roles. A major advantage of aerial combat is their ability to perform acrobatics.
The Su-30 has a service ceiling of over 50,000 feet. It has a 30mm autocannon with 150 rounds and 12 hard points that can carry 18,000 pounds of ordnance. The Su-35 can travel at speeds of 1,500 mph and a ceiling of 59,000 feet.
The Su-34 was supposed to be the replacement for the aging Su 24. It has a top speed of 1,100 mph and has a single 30mm autocannon with 180 rounds.
Four Su 30s have been shot down, with one destroyed on the ground. A Su-35 with anti-radiation missiles has been shot down. The Su-34s were shot down. There are at least three aircraft that are not known.
Russian officials and state media have said that Russia's fifth-generation stealth fighter, the Su-57, has been used in the war in Ukraine, but observers don't think it's being used much.
In other conflicts, aerial drones have been used. Russian and Ukrainian drones have been downed in the fighting.
The Orlan 10 is a small propellor-driven plane that is used to spot targets and even drop small bombs. Russian drones are used to strike Ukrainian targets as well.
The Bayraktar TB2 was used by the Ukrainians to hit Russian targets. As Russian forces improve their defense, Ukrainians and their international supporters have crowdfunded the purchase of more drones.