Part 5/10:
The investigation also uncovered the Aircraft Communications Addressing and Reporting System (ACARS) data, which recorded critical pre-takeoff information. Curiously, the tail number for Flight 77 appears inconsistently in records, sometimes displayed as unidentified. Adding to the mystery, there was reportedly no Emergency Locator Transmitter (ELT) signal emitted upon the alleged crash at the Pentagon, a situation experts deem improbable in situations of aviation disaster.