Russian Air-Space military forces are now very limited to cross Ukrainian territory and just launch long-range missiles from inside Russian airspace, report USA official.
Russian military jets make about 20 times more combat flies than Ukrainian forces. Russia's roughly 200 daily Ukraine-connected sorties compare to about five to 10 a day by Ukraine, which is down to about 56 operational warplanes, the official told reporters at the Pentagon - DefenseOne reports.
Read more: Day 17th of Ukraine's Defense Against Russian Aggression (Live Updates)
There are several reasons for the conservative use of airpower over Ukraine on both sides, the defense official said. They overlooked risks of using enemies’ Air Defense systems.

"They're being very nimble, and it's proven effective. And I'm not just talking about mobile launchers,” the defense official said. “I'm talking about the use of shoulder-fired surface-air missile capability, as well … they are making the caution of the Russian pilots warranted, by the way they're using the capabilities that they have."

On Friday, the Ministry of Defense of Ukraine claimed it were shot down a total of 57 Russian aircraft and seven Russian drones. That number could not be independently verified by Pentagon

Third, the Ukrainians have relied on drones, especially to attack Russian convoys.
“They have made effective use of drones, which are cheap,” the defense official said. “They can fly below radar coverage by the Russians …they're using them with terrific effect, particularly against Russian ground movements.”
Over the last two days, Pentagon and Biden administration officials rejected a proposal by Poland that Warsaw would send its MiG-29s to Ramstein Air Base in Germany, and leave it to the U.S. and NATO to decide whether to send those jets on to Ukraine. The U.S. said that transfer was a non-starter, because of the risk of further escalation with Russia.

Likewise, the United States will not send its advanced Patriot air defense system because it would require U.S. troops to operate it inside Ukraine, the Pentagon said on Thursday. Instead, the United States and NATO member countries are looking for additional alternative systems, such as the Russian-made S-300 air defense system, that Ukrainian troops already know how to operate.
Read more: Day 17th of Russia's Full-Scale War Against Ukraine: Russian Losses Increasing