An aircraft comprising: an aircraft avionics system qualified with respect to one or more predetermined reliability, safety, and/or security standards, and configured to perform one or more functions; and an interface module qualified with respect to the one or more predetermined reliability, safety, and/or security standards; the interface module further comprising a first and second database; and configured to: store in the first database, a list of functions performable by the aircraft avionics system; and, store in the second database, for each function, respective one or more function criteria, the function criteria specifying how the function is to be used; wherein the interface module is further configured while the aircraft is in flight to; receive, from a non-qualified entity remote from the aircraft avionics system, a function request for the aircraft avionics system to perform a certain function; test the certain function against the list of functions of the first database and the function criteria of the second database; and, responsive to determining that the certain function satisfies all of the function criteria that correspond to the certain function, outputting the function request for use by the aircraft avionics system, wherein the interface module is further configured to, responsive to determining that the certain function does not satisfy at least one of the test criteria that correspond to the certain function, close a communication link between the interface module and the non-qualified entity remote from the aircraft avionics system. an aircraft avionics system qualified with respect to one or more predetermined reliability, safety, and/or security standards, and configured to perform one or more functions; and an interface module qualified with respect to the one or more predetermined reliability, safety, and/or security standards; the interface module further comprising a first and second database; and configured to: store in the first database, a list of functions performable by the aircraft avionics system; and, store in the second database, for each function, respective one or more function criteria, the function criteria specifying how the function is to be used; store in the first database, a list of functions performable by the aircraft avionics system; and, store in the second database, for each function, respective one or more function criteria, the function criteria specifying how the function is to be used; wherein the interface module is further configured while the aircraft is in flight to; receive, from a non-qualified entity remote from the aircraft avionics system, a function request for the aircraft avionics system to perform a certain function; test the certain function against the list of functions of the first database and the function criteria of the second database; and, responsive to determining that the certain function satisfies all of the function criteria that correspond to the certain function, outputting the function request for use by the aircraft avionics system, wherein the interface module is further configured to, responsive to determining that the certain function does not satisfy at least one of the test criteria that correspond to the certain function, close a communication link between the interface module and the non-qualified entity remote from the aircraft avionics system. receive, from a non-qualified entity remote from the aircraft avionics system, a function request for the aircraft avionics system to perform a certain function; test the certain function against the list of functions of the first database and the function criteria of the second database; and, responsive to determining that the certain function satisfies all of the function criteria that correspond to the certain function, outputting the function request for use by the aircraft avionics system, wherein the interface module is further configured to, responsive to determining that the certain function does not satisfy at least one of the test criteria that correspond to the certain function, close a communication link between the interface module and the non-qualified entity remote from the aircraft avionics system.