Carstens Publications, known for their magazines Flying Models, Railfan & Railroad, and Model Railroad Craftsman, has gone out of business as of August 22nd, 2014, according to a statement posted to their website. Carstens was founded in 1933 and their first product was The Model Craftsman, which eventually became the magazine we know today as Model Railroad Craftsman. Carstens has been a staple in the hobby industry for more than 50 years.
According to the statement on their website, "...the current economic climate has placed us in this position," indicating the magazines were not selling well, or perhaps advertisers were spending their dollars elsewhere. Whatever the case, "discussion is continuing with several parties who expressed desire to take on the continuance of the magazines." So it's possible to see these magazines transistion to a new publisher. No word on the two annual publications, 0n30 Annual and HOn3 Annual.