19.D.1."Software" which coordinates the function of more than one subsystem, specially designed or modified for "use" in the systems specified in 19.A.1. or 19.A.2.

Note:
For a manned aircraft converted to operate as an unmanned aerial vehicle specified in 19.A.2., Item 19.D.1. includes "software", as follows:
a. "Software" specially designed or modified to integrate the conversion equipment with the aircraft system functions;
b. "Software" specially designed or modified to operate the aircraft as an unmanned aerial vehicle.