Aero Union used to have 3 P2V's in the stable. They were modified by Aero Union to meet the California rule of being able to land loaded. They did things a bit differently at CAL FIRE (formerly known as the California Department of Forestry or CDF). When a smoke is spotted, they launch everything they have within a certain radius. Most everybody got cancelled on the way to the fire, unless the thing is huge and growing.
A loaded P2V, such as the one’s flown by Neptune Aviation (formerly Black Hills), is above its maximum landing weight. So, a cancelled dispatch in one of those P2's meant you had to pitch the load in the woods in order to land. Aero Union pulled off the jets and used only the inboard fuel tanks in order to meet the maximum landing weight. They were good airplanes, faster than the Black Hills model and they climbed better once you got them up to speed. Dean and I were flying an Aero Union version, which they called the SP2H. They sold them all and they have all now been scrapped.
That SP2H designation was borrowed from the Navy and has nothing to do with the real SP2H designation that the Navy used on some Neptune’s. I think Aero Union didn't know what to call their version and they wanted the agencies to be able to recognize and differentiate between theirs and the other P2's flying at the time. Aero Union especially wanted CDF to recognize the Aero Union version as an airplane that met the loaded landing requirements of a CDF contract.