The date the Hindenberg's explosion occurred on was Thursday, May 6th, 1937, in Lakehurst, New Jersey.
Jason mentions that the family heard about the Hindenberg disaster on the Blue Network. The Blue Network was one of the two Radio Network's owned by NBC Radio, whose parent company was RCA. It was launched on January 1, 1927, and was formerly called NBC Blue Network until 1942 when the name was changed just to Blue Network. In 1947 the Network became the American Broadcasting company. NBC was forced to sell the network in 1943 due to a court order in an Anti-Trust suit and ruling against NBC.
The flaming debris falling on John-Boy after the Hindenburg explodes were actually pieces of torn blue jeans, dipped in kerosene and lit on fire.
Asking John-Boy about the disaster, Elizabeth says, "It sure sounded gruesome on the radio. The announcer was crying." She is likely referring to broadcaster Herbert Morrison (1905-1989) who was covering the story for WLS in Chicago. Morrison's emotional on-air reporting of the disaster as it was happening is one of the most famous moments in broadcasting, particularly known for his exhortation, "Oh, the humanity!"
The newspaper Grandpa is reading is The Daily Progress out of Charlottesville, Virginia. It's been published daily since 1892.