On the night of April 29, 1954; several USAF RB-45Cs fly over Moscow. Technically, they weren't USAF aircraft, because at the time, they were being flown by RAF crews.
In May 1955, six RB-47s flew straight past the Urals mountain and into the Soviet heartland,
In May 1956, three RB-57s did a simultaneously overflight of Vladviostock, getting us holiday snaps from 3 different directions.
And here's a Story from a RB-47 crewmember:
Link
By this time, we had covered two more major airfield targets near Arkhangelsk and were turning to the Southwest toward our last two targets. We had been over Soviet territory an hour and were at 40,000 feet. We had been briefed by Intel that the Mig-15 would not be able to do any damage to us at 40,000 feet with our true air speed on the order of 440 knots.
Well, you can imagine what we called those Intelligence weenies as the first Soviet Mig-17, not Mig-15, made a firing pass on us from the left rear, and we saw cannon tracer shells going both above and below our aircraft. And, the Mig was still moving out rather smartly as he passed under us in front. So enough of this 40,000 feet stuff, I pushed the RB-47 over, descending a couple of thousand feet picking up about 20 knots indicated airspeed in the process. The second Mig-17 made his firing pass and I don’t care who knows, it was scary watching tracers go over and under our aircraft. This guy had almost come up our tailpipes.
Fortunately, when the third Mig started his pursuit pass, our guns burped for a couple of seconds. General LeMay did not believe in tracers for our guns, but the Soviet pilots must have seen something because the third guy broke off his pass and the flight of six, and the next flight which joined us later, stayed out about 30 to 40 degrees to side, out of the effective envelope of our guns. Of course, the Migs didn’t know that our guns would not fire again, even though the Co-pilot pleaded, and I believe he did, at least, kick the panel trying to get them to work.
The fourth Mig of this flight made a firing pass and made a lucky hit through the top of our left wing, about 8 feet from the fuselage through the wing flap. It exploded into the fuselage in the area of the #1 main tank and knocked out our intercom. We felt a good whap and all three of us were a little bit anxious (scared) but doing our mission as briefed, basically because of habit. I firmly believe that’s what good, tough, LeMay-type, SAC training did for his combat crews. Later we also found out, it hit our UHF radio in a way that it would not channelize but was stuck on channel 13, our command post common.
By now we had covered our last photo target and had turned due west toward Finland to get the hell out of there. That flight of six ran out of range I guess and, we were near the Finland border. Real soon another three Migs showed up. Two Migs of this flight made individual firing passes but our added speed obviously made it a bit tougher or I am pretty sure I would not be here writing about this mission today. After those two made passes, on of the Migs came up on our right side, close enough to shake hands and sat there for two or three minutes. Two more Migs tried firing passes, but without hitting us, by this time we were well out of Soviet territory. At the debriefing in Omaha, General LeMay asked, ?Why were you not shot down?? My answer was that there was no doubt in my mind the Mig-17 pilots could have shot us down, if they had been willing to come right up our tailpipes! He made a statement that he was “convinced that most fighter pilots are basically cowards anyway.” General LeMay also said, “There are probably several openings today in command positions there, since you were not shot down.”
Our excitement for this mission was not over. An airborne stand-by KC-97 tanker was holding for us about 50 miles from Stavanger, Norway. We really weren’t sure how the damage to our left wing and fuselage would effect fuel consumption. Initially it didn’t look that bad. As we came into radio range of our airborne tanker I heard him calling (garbled) in the blind on command post common, the only working part of our UHF radio. We were running about 30 minutes behind schedule; I heard the tanker state he was leaving the orbit area at the appointed time. I tried to acknowledge his call but he later said he never heard me transmit anything. Of course they had not been briefed on our mission, but were aware that three B-47’s went through refueling areas that morning and only two had returned.