Part 3/9:
A Routine Flight Turns Awry
With the pre-flight issues resolved, the flight eventually took off at 10:06 AM. Everything appeared to be going smoothly until about 15 minutes into the flight when the primary IRU began to malfunction. The navigation computer unexpectedly switched from the functioning unit to the newly installed faulty one, which slowly began to feed incorrect positional data to the crew.
As the pilots followed the indications on their navigation displays, they remained oblivious to the deceptive course change. A cautionary alert indicated that the plane was now relying solely on the IRU for navigation, but the crew misinterpreted this as a temporary loss of signal rather than a potentially catastrophic malfunction.