Aluminum Body and Lightening

Many years ago in Belize a pilot and I were returning from tasking in the middle of the country in an RAF Puma helicopter. It was the rainy season and we found ourselves cornered by thunderstorms and in an area of the jungle where there were no landing sites so we pushed on through the weather. After landing I got out to do the After flight checks which included checking the rotor blades. There was a small "blister" about the size of a quarter on the underside of one of the blades so I got the ladder out to inspect it. There was an identical "blister" on the top side of the blade in the same place. I called over a senior tech and showed it to him. He immediately identified it as a lightning strike. Funny thing was neither the pilot nor myself had any idea it had happened...