A couple of reminders that aircraft need and get upgrades until the end of their service lives:
-- A photo of a Navy Boeing E-6B Mercury coming out of a modification center with upgrades to systems in 2023. The E-6B is scheduled to be replaced for strategic communications by a C-130 variant in coming years. This photo of the rear of the E-6B shows the two long antenna outlets: one at the very rear of the tail and the other partially hidden behind the crowd on the rear belly of the aircraft. I believe the successor EC-130 will use the same transmission system: Two very long trailing wires that are deployed while the aircraft flies a circular pattern and become essentially vertical.
https://en.wikipedia.org/wiki/Boeing_E-6_Mercury
-- A photo of a U.S. Army UH-60V Blackhawk, a modification of an older UH-60L with glass cockpit and integrated avionics, delivered to a unit in Europe and replacing UH-60Ms. The Army has chosen a new tilt-rotor design to replace the large number of Blackhawks in service, but that process will take years.
Over 5,000 Sikorsky model S-70 helicopters have been built since the first flight in 1974 and the type remains in production, making the UH-60 -- and its many derivatives serving armies, air forces, navies and civilian users around the world -- ubiquitous in the world of rotary-wing aviation. As I previously posted, the Chinese armed forces have now begun production of a modified copy, ensuring that the S-70/H-60 will be seen in the skies for many years to come.
https://en.wikipedia.org/wiki/Sikorsky_S-70