What should all U.S. registered aircraft numbers begin with?

In the United States, all registered aircraft must have a unique identification number known as the tail number. This tail number is essential for flight operations and identification of the aircraft on the ground and in the air. The Federal Aviation Administration (FAA) has established that all U.S. registered aircraft numbers begin with the letter "N." This designation is significant as it differentiates U.S. aircraft from those registered in other countries, each of which has its own prefix according to international standards.

The letter "N" is part of a regulatory framework that also includes numbers and can be followed by up to five additional characters, which are often a combination of letters and numbers. This system helps maintain an organized registry of aircraft and ensures that every aircraft can be tracked and identified appropriately. Thus, the designation with the letter "N" is a nationally recognized standard for U.S. aircraft registrations.