What is MMO (maximum operating Mach number) for the aircraft?

• A. 0.80 Mach
• B. 0.82 Mach
• C. 0.84 Mach
• D. 0.86 Mach

Answer: (B)

MMO is the maximum operating Mach number—the fastest speed at which the aircraft is certified to fly in normal operations without risking structural or aerodynamic limits. For the P-8A Poseidon, the MMO is 0.82 Mach. This limit is set to keep you safely below the onset of Mach buffet, loss of control effectiveness, and other high-speed envelope issues across weight, altitude, and configuration.

So, the reason 0.82 Mach is the correct choice is that it represents the certified upper speed cap for normal flight. Operating up to this speed ensures you stay within the designed performance margins. Speeds lower than this (like 0.80 Mach) are permissible but not the maximum limit, while higher values (0.84 or 0.86 Mach) would exceed the certification limit and are not allowed under normal operations.