VMCJ 1 marked a single EF 10B Skyknight with graffiti in Russian in 1965

As told by Joe Copalman in his book F3D/EF-10 Skyknight Units of the Korean and Vietnam Wars, although crews flying  Peacetime Aerial Reconnaissance Program (PARPRO) missions to collect intelligence on radar systems in China, North Korea and the Soviet far east remained in international airspace and relied on standoff receivers to collect intelligence, communist air arms from the nations being spied on routinely sent MiGs up to intercept and investigate the surveillance flights. 

In most cases, these intercepts involved MiGs harmlessly flying wing on an F3D-2Q before turning back.

 Recalling one such peaceful intercept, Skyknight pilot Chuck Houseman said; 

 ‘The first time we were intercepted, they reported that we were taking pictures of them, as we were carrying 35 mm hand-held cameras. Normally, it would be on the pilot’s side where the interceptors were, and the ECMO would lean across and snap some pictures of them. And the Russians would report, “They’re taking pictures of us. What should we do?” One of the Russian controllers had a sense of humour and said “Smile”. 

 ‘This was not authorised, but we thought we’d jazz up the situation a little bit, so we somehow or another were able to come up with the Russian language that said ‘JOIN THE U.S. MARINE CORPS’ and painted it on the side of the fuel tanks on the F-10s so that Soviet MiG pilots could read it 

 There was a conversation, we learned later on, when the interceptors came up – they got a little closer than usual and were reading it off to the ground controller. They reported it, and there was no response, so they reported it again and there was still no response, so they dropped it. 

 ‘The painting on the fuel tanks caused some big turmoil in the background in Washington, D.C., with the NSA wondering what the hell was going on. By the time the information rolled down to us, the second flight was up there with those same markings, and they didn’t want to turn him around when he was already on his way out, but they passed the word down, “Paint that damned thing over and get rid of it”.’

https://theaviationgeekclub.com/the-ef-10b-skyknight-that-had-a-graffiti-in-russian-language-saying-join-the-u-s-marine-corps-painted-on-fuel-tanks-so-that-soviet-mig-pilots-could-read-it-during-intelligence-missi/