These likely represent internal project codes, specific simulation modules (e.g., Tanker or specific aircraft variants), or geographic identifiers. For instance, TN frequently refers to Tennessee in administrative and government documents. Potential Origins of the File
Acronyms like LTD are sometimes used for Learning Technology Directories , suggesting the ZIP could be a proprietary data feed for a training curriculum. Download LTDV AATD TNK zip
If the file relates to the Aviation Applied Technology Directorate, it may be hosted on a secure portal for authorized personnel or contractors rather than a public web index. Important Considerations for Downloads FAA AC 61-136B - Advisory Circular These likely represent internal project codes