Final answer:
The location of the air traffic control contingency plan depends on the specific manual and can vary by version or governing aviation authority. Therefore, it's essential to consult the particular air traffic control manual to locate the contingency plan's appendix.
Step-by-step explanation:
The air traffic control contingency plan is a significant component in ensuring continued air safety and efficiency during emergency situations or system failures. Details of such contingency plans are typically outlined in documentation associated with air traffic control procedures. While these documents can have varying structures depending on the country or governing body, in many cases, the contingency plan might be located in an appendix at the end of a manual or document.
Without access to a specific document, we cannot definitively identify whether the air traffic control contingency plan is in Appendix A, B, C, or D. However, it is essential to consult the specific air traffic control manual in question, as the appendix containing the contingency plan can vary depending on the manual's version or the guidelines established by the aviation authority responsible for the document.