What is "tacco"

A TACCO (military abbreviation for "TACtical COordinator") (pronounced 'TACK-oh') is the aircrew member responsible for coordinating the activities of the part of the crew responsible for the tactical operation of the aircraft and its systems. The TACCO may, depending on the country, be the Mission Commander of the crew.

Typically, TACCOs run the missions in CH-124 Sea King helicopters, P-3 Orion patrol aircraft and S-3 Viking aircraft. They are specially trained for antisubmarine warfare tactics, but also participate in other missions in which these aircraft are involved.