Add TSA precheck to American Airlines profile is a quick and easy way to enjoy expedited security screening. To do this, log in to your AAdvantage account, go to the "Your Account" section, and enter your Known Traveler Number (KTN) under "Secure Traveler." This will ensure TSA PreCheck is applied to all future bookings. If you’ve already booked a flight, you can add your KTN by updating your reservation online or by calling customer service. With TSA PreCheck, you can bypass regular security lines, keeping your shoes, belt, and light jacket on for a smoother travel experience.