Do any Metallica songs from the 80's (thrash metal songs) get radio airplay in the US today?
I haven't regularly listened to music radio in probably two decades, but I would guess that there are stations that have dedicated metal shows that play stuff like Fade to Black, MoP, Sanitarium and One (and maybe a couple others).
Also, I am 47 years old and have never in my life heard Iron Maiden on the radio.
Back in the day (i.e., from the mid-80s to the mid-90s). Maiden was probably more common than Metallica on stations in Southern California (KMET, KNAC and, to a lesser extent, KLOS). In particular, Flight of Icarus, The Trooper, Aces High and Two Minutes to Midnight were in heavy rotation during the Powerslave album cycle and tour. That started changing around the time the Black Album was released and Bruce left Maiden.
You mean even the tunes from their 80's thrash metal period are popular among the mass of non-metal fans, not only the hits from the Black album (and onwards)? More popular than 80's Maiden tunes as Run to the Hills, Number of the Beast, Hallowed be thy Name, The Trooper, Flight of Icarus, Aces High, 11:58, Wasted Years?
There's no available survey material, but I would imagine that a decent chunk of the folks who show up at Metallica concerts only know the "hits" from the pre-Black Album era. Starting with the Black Album, Metallica gained a lot of "non-traditional" fans. Around the same time, Maiden lost
a lot of momentum as a result of two albums (NPFTD and FOTD) that were not as well received as the prior catalog, the rise of grunge, and the loss of Bruce Dickinson. Even after Bruce returned, Maiden has never regained the status it enjoyed in the 80s. Even though the five "reunion era" albums have charted well in the U.S. (and, in fact, the three most recent albums are the band's highest charting albums in the U.S.), none of them has achieved "Gold" status in the U.S.