PHIBRON is an abbreviation for Amphibious Squadron. In the U.S. and NATO, it is a tactical and administrative organization composed of amphibious assault shipping to transport troops and their equipment for an amphibious assault operation.[1]
A U.S. PHIBRON usually consists of three amphibious ships, typically one LHD, an LSD and an LPD. When the ships of a PHIBRON are loaded up with the forces of a Marine Expeditionary Unit and some additional Navy units (including landing craft from two or more Assault Craft Units or ACU), it is designated as an Amphibious Ready Group (ARG). The officer in charge of PHIBRON SIX is designated COMPHIBRON SIX or Commander Amphibious Squadron Six.
Before the advent of modern helicopter-oriented amphibious warfare, the amphibious squadron was made up differently, depending on the era. During the 1960s, a typical squadron might consist of an Attack Transport (APA/LPA), a Dock Landing Ship (LSD), an Attack Cargo Ship (AKA/LKA), one or two Landing Ships, Tank, (LST) and, especially if there were only one LST, a High Speed Transport (APD). The APA carried troops and LCVPs in which to land them, plus a few LCMs for bigger loads. The AKA carried cargo and an assortment of LCVPs and LCMs with which to land it. The LSD carried boats. The LST carried tanks and other rolling stock, and had the ability to discharge its cargo directly onto the beach. The destroyer-like APD provided limited gunfire support and fast defense of the squadron. It frequently also carried a UDT unit or other similar troops.
The Landing Platform Helicopter (LPH) replaced the APA in the late 1960's and provided helicopters to land troops and supplies inland, beyond the beach.