Genuinely, where have you heard said reports as to the best of my knowledge I've not seen or heard anything as of late, unless I've missed it.
Any links would be appreciated. But without seeing anything, it's a perculiar one as the performance of the Russian Air Force has been worthy of discussion.
Not since the early days of the war have they came close aerial superiority - let alone domination - with growing losses of fixed wing and rotary aircraft.
@Mutzo Nutzo has far more more experience than myself regarding air assets, but for me their restricted use has brought about many questions.
On the face of it, they have more aircraft, more advanced aircraft and experience than their counterparts, yet this imbalance hasn't had the desired impact.
To obtain victory, why haven't they committed more assets before now? Why haven't they utilisied their
apparent advantage to obtain victory?
If you start to infer, you get a few scenarios, which may overlap. There's a lot of talk about poor maintenance regimes, lack of spare parts and whatnot.
Maybe, their operational fleet is way below their inventory. We've got the issue of poor training, including rigid tactics, which has meant they're at risk of loss.
Same with questions regarding the actual prowess of their aircraft, which NATO has typically overstated (see The Mig-25/Foxbat as an example of this).
With the Ukraine's increasing AD, all the above has meant that they're far more susceptible to being downed than they'd hope, so maybe they're risk adverse.
So after perhaps labouring the point, I to some extent doubt that Russia would now amass and use a larger force of aicraft because why haven't they already.
If they were to, I have doubts about their impact compared to potentinal losses that Russia will likely struggle to ever replace in suitable numbers or at all.
Long after this war is concluded, Russia will need to defend its airspace or deal with other conflicts and will need numbers to do it. Will they take the risk?
It's similar to why they haven't commited many of their newer tanks (T-90) because they can't afford to lose them, let the west have them and see they're crap.