Actually they both got started using Tower to carry their freight until they got certificates.
Nope. SO not true. Revisionist history from the Polar guys AGAIN.
Southern Air began business in Miami FL as a front company for the CIA. It was founded in 1947 and became a subsidiary of the CIA's airline proprietary network known as the Pacific Corporation. Even though Congress divested the Government of any for profit corporations in 1976, the Certificates were sold to a CIA lawyer named Jim Bastian who continued to operate the airline for the CIA. He even wet leased his L382s to a group of Pilots called "East Inc." who then operated directly for the CIA. Bastian owned SAT until the Bankruptcy in 1998 and his death in 1999.
Tower on the other hand was co-founded, majority owned, and managed by Morris K. Nachtomi, who was an Israeli who immigrated to the US in 1981. He had been employed by El Al and when he came to the US he started working with a company called Tower Travel Corporation. 1n 1982 he co-founded Tower Air with Zev Melamid, Mordechi Gill, and Sam Fondlier.
Tower Air filed for Chapter 11 in Feb of 2000 (Feb 29th to be exact) and ceased all operations on May 1st of that year, surrendering its FAA certificate in November of 2000.
Polar was formed in 1993 as a joint venture between Southern Air Transport and Jack Welch's GE Capital Aviation Services which had a bunch of old Flying Tigers lease returns (from Polaris Leasing, a division of GCAS) just sitting around. Polar began operations in June of 1993 with Charter flights and gained its Supplemental Certificate in 1994. After several years of modest growth, the entire company was acquired by GECAS.
In November of 2001 Polar was acquired by Atlas Air World Wide Holdings a company formed by upstreaming profits from Atlas Air Inc. and indeed having all of the same major officers as Atlas Air.