The engine also had to be designed to be inexpensive; the military wanted to produce and store large quantities of the missile.

The J402-powered Harpoon had an excellent service record, including sinking two Libyan warships during the 1986 Gulf of Sidra incident.

The compressed air was combusted in an annular combustor, and then passed through a single high-pressure turbine stage before being exhausted.

All the engine accessories, like the fuel pump and electrical alternator, ran directly off the rotor shaft.

Teledyne designed and tested the new two stage axial compressor early in the J402's life (mid 1970s), but did not work on the new turbine (and subsequently the -702 variant of the engine) until nearly a decade later in the mid-1980s.

The primary changes are an aerodynamically refined axial compressor and turbine section, resulting in a more fuel efficient engine at the same thrust levels as the -400.

[9] Data from ,[10][11] Comparable engines Related lists Leyes, Richard A. II; William A. Fleming (1999).