The Ukraine war has been fought largely on the ground in the past two years, with troops often locked in back-and-forth battles with heavy artillery and drone support. The countries’ air forces have played second fiddle because of Ukraine’s limited fleet of planes and Russia’s inability to gain the air supremacy it once expected.

But as the Russian military presses on with attacks in the east, its air force has taken on a greater role. Military analysts say Russia has increasingly used warplanes near the front lines to drop powerful guided bombs on Ukrainian positions and clear a path forward for the infantry. That tactic, used most notably in Avdiivka, the strategic eastern city captured by Russian forces last month, has yielded good results, experts say.

It has also come with risks.

“It’s a costly but quite effective tool that Russia is now using in the war,” said Serhiy Hrabskyi, a retired Ukrainian army colonel. “It’s dangerous for them to send their fighter jets” close to the front line, he added, but it can “impact Ukrainian positions effectively.”

The Ukrainian Army last week said it had shot down seven Su-34 fighter jets, nearly all operating in the east, just a few days after downing an A-50 long-range radar reconnaissance aircraft. It was, according to Ukrainian officials, part of a series of successful strikes against the Russian Air Force, in which Ukraine claimed to have shot down 15 planes in as many days.

The majority of the shootdowns could not be independently verified.

Oryx, a military analysis site that counts losses based on visual evidence, and Russian military bloggers confirmed the loss of two Su-35 fighter jets. Britain’s military intelligence services confirmed the destruction of the A-50 plane.

Justin Bronk, a senior research fellow for air power and technology at the Royal United Services Institute in London, or RUSI, cautioned that “overclaiming on kills is a systemic feature of air warfare.”

But he added that Ukraine “has certainly been conducting an increasing number of ambush type engagements” with the help of air defense systems in recent months and has racked up “notable successes.”

After the invasion in February 2022, Ukraine managed to keep Russia from controlling the skies through air combat and the skillful use of antiaircraft missiles. After only a month and heavy losses among its warplanes, Russia stopped flying its aircraft beyond the front lines, RUSI said in a report, turning instead to launching barrages of cruise and ballistic missiles from afar.

But that left Russia “unable to effectively employ the potentially heavy and efficient aerial firepower” of its fighter-bombers to strike Ukrainian frontline positions, the report said.

This began to change early last year when Russia started using glide bombs, guided munitions that are dropped from a plane and can fly long distances to the front lines, limiting the risk to planes from antiaircraft missiles. Carrying hundreds of kilograms of explosives, the glide bombs can smash through the underground bunkers that protect soldiers at the front.

“These bombs completely destroy any position,” Egor Sugar, a Ukrainian soldier who fought in Avdiivka, wrote on social media. “All buildings and structures simply turn into a pit after the arrival of just one.”

Ukrainian officials and military analysts said Russian aviation had played an important role in the capture of Avdiivka, one that required Russian jets “to fly closer” to the front line to maximize the effect of the glide bombs. And that exposed them to the risk of being shot down by Ukraine’s air defenses.

In late December, the Ukrainian Army said it destroyed three Su-34 jets near the Russian-controlled eastern bank of the Dnipro River in the south, where Ukrainian troops have secured small positions. Then came the shootdowns in the east.

It remains unclear which air-defense systems Ukraine has deployed. But some army officials and analysts have hinted at the use of U.S.-made Patriot systems, America’s most advanced ground-based air defense system.

Tom Karako, the director of the Missile Defense Project at the Washington-based Center for Strategic and International Studies, said the Russian losses probably were the result of “some relationship between the Russian aircraft being put in harm’s way,” Ukraine’s intelligence gathering on the movements of Russian planes and the deployment of air-defense systems “to take them out.”

The Institute for the Study of War, a Washington-based think tank, said “Russian forces appeared to tolerate an increased rate of aviation losses in recent weeks in order to conduct glide bomb strikes in support of ongoing Russian offensive operations in eastern Ukraine.”

One of Ukraine’s biggest successes in the air battle was the destruction last week of one of Russia’s A-50 radar planes — the second this year — which are critical in coordinating aerial bombardments of Ukrainian positions on the front. “Taking out their eyes, and taking out their targeting ability, that’s a pretty good win,” Mr. Karako said.

Britain’s military intelligence said Russia had seven other A-50s but that it had “highly likely grounded the fleet from flying” in support of its military operations to prevent further losses, thus reducing the “situational awareness provided to aircrews.”

The Ukrainian Air Force said Russian aviation activity in eastern Ukraine had significantly subsided by Saturday evening.

It is unclear to what extent Russia can sustain these losses in the long term. RUSI analysts said this month that Russian aircrew losses amounted to nearly 160 personnel, which they described as “a serious loss of capability.”

The Russian state news agency Tass said on Thursday that the state-owned defense conglomerate Rostec would resume production of the A-50 “since it is needed by the Russian armed forces.”

Mr. Hrabskyi, the retired colonel, likened Russia’s costly strategy in the air to its tactics on the ground, where it has sent wave after wave of troops in bloody assaults to capture cities, regardless of the human cost. “The Russians don’t care,” he said. “If they have an order, they will use all available capabilities, all available weapons systems to attack.”