From that I understood:
1) Stealth on some Tu-160 components (like fans) was already present from the first built Tu-160?
From the first model Tu-160 aerodynamics was top priority because it needed to be a mach 2 bomber... RCS reduction was also important and a lot of work was done to reduce it but it wasn't the primary focus.
The result is reduced detection ranges, not actual stealth as such.
2) The stealth on a Russian strategic bomber is considered important, but not essential. Correct?
As an example the sharp Mig-25 air intakes on the Tu-22M3 increased RCS from the front by something like 25%, but they accepted that because of the increase in flight performance they got with that change and the new engines.
Also keep in mind... these are all mainly cruise missile carriers that will deliver weapons from significant standoff distances.
A minor reduction in RCS that reduces detection range from 5,000km to 4,200km can be rather more significant due to flight speed and therefore the amount of time it will be visible to enemy radar... if the aircraft can get in... launch its missiles and leave before enemy fighters are scrambled in time to intercept it will remain safe even if it is seen.
3) When on display at the air shows, the ground crews put on the covers on the engine intakes on the Tu-160s also because of the stealth measures in the turbofans?
Yes, though it also prevents FOD issues as well.
4) Some Tu-160s (10, maybe more) were sent to an upgrade program that also includes stealth.
You cant add stealth to an existing design... actual stealth has to be a design priority from the start and can be ruined if the focus wanders.
They have said that by 2020 they should have about 10 more
operational Tu-160Ms unless one or more are lost in accidents.
You can take that to mean a few different things... either the fleet will be reduced to 10 aircraft, all of which will be Tu-160Ms, or of the 16 operational Tu-160s 6 have already been given upgrades so from now till 2020 just 10 remaining aircraft need the upgrade to have 16 Tu-160Ms in operational service (assuming no losses... touch wood).
With the upgrade they will improve (reduce) the RCS further, but it will never be stealthy as such.
Again, is the Tu-95MS a Tu-142?
In the 1970s they upgraded the design of the Tu-95 to improve its wing design and aerodynamic efficiency and improve performance. The new design was called Tu-142 and the new planes built in the 1980s and 1990s were of the new improved design.
The Tu-95MS bombers in service now are of this new design.
Could the Bear-H receive RAM materials?
Could the Tu-22M receive RAM?
Yes, and they probably will take the time to replace some parts and update some materials and add RAM here and there where the RCS levels are particularly high because it wouldn't cost much but the result would be rather worth it.
Think about it in terms of the laws of diminished returns... in a modern airliner it is the engines and avionics that have made the greatest progress in terms of flight efficiency since the late 1930s, so if you wanted to upgrade a plane from that period replacing the engines would be a good place to start to get the most bang for your money.
The next area will be improved wing shape and then new materials and with a few more dollars spent you would end up with about the best design you could manage without a complete redesign.
The problem of course is that aircraft of that period had straight wings which is not ideal at high subsonic speed.
You could make the propeller blades composite and radar transparent, and lots of other changes, but the cost might not make the bomber that much more effective in its role as bomb truck or cruise missile carrier yet it might increase purchase and operational costs to make it too expensive to use.
With a plane like a Mig-29A you would examine the design in terms of radar returns and look for all the corner reflectors that give off strong signals... many areas you can reshape and add RAM... if you take away 4 or 5 strong reflecting areas you can dramatically reduce the RCS of the aircraft, but after you have dealt with the obvious problem areas then further reductions become much much harder and also orders of magnitude more expensive too.
Changing a design will never result in a signature as low as a plane custom designed from scratch can achieve but it is cheaper unless stealth is the goal.
The Tu-22M3s intakes greatly increase the RCS and a few changes in shape and materials and the application of RAM could greatly reduce the RCS, but the Tu-22M3M is never going to be a stealthy aircraft, so you don't want to spend all the upgrade money on that when new engines and new weapons and new radar can have a much more significant effect on its performance... stealth can be a money pit that will suck up all the money you have if you let it.
Many thanks, but sorry if I insist, it isn't that I don't believe you, but if possible do you have some source to show me about the Tu-160 stealthy? (Also in Russian language).
Stealthy is too strong a word.
Stealth implies they can't see you, the Tu-160 is designed to use lower RCS with speed so they can't see it till it is too late to do anything about it.
Even the wiki entry says that...
Although the Tu-160 was designed for reduced detectability to both radar and infrared, it is not a stealth aircraft.
The purpose is not to allow it to fly over US soil with impunity, it is to delay the moment of detection x thousand kms off the US coast... it is not to reduce detection range to single or double digits but to reduce them to 3 digits from 4...