For a Northeast-bound route, the cruising altitude should be which parity?

For a Northeast-bound route, the cruising altitude should be which parity?

• A. Even
• B. Odd
• C. Both
• D. None

Answer: (B)

The concept being tested is how cruising altitude parity is assigned based on flight direction. In US IFR operations, northbound and eastbound routes use odd-numbered altitudes (odd thousands of feet MSL plus 500 feet), while southbound and westbound routes use even-numbered altitudes (even thousands plus 500). Since a northeast-bound route combines both northbound and eastbound directions, the altitude must follow the odd parity rule. Therefore the cruising altitude should be an odd multiple of 1000 plus 500 feet, such as 3,500, 5,500, or 7,500 feet.

The concept being tested is how cruising altitude parity is assigned based on flight direction. In US IFR operations, northbound and eastbound routes use odd-numbered altitudes (odd thousands of feet MSL plus 500 feet), while southbound and westbound routes use even-numbered altitudes (even thousands plus 500). Since a northeast-bound route combines both northbound and eastbound directions, the altitude must follow the odd parity rule. Therefore the cruising altitude should be an odd multiple of 1000 plus 500 feet, such as 3,500, 5,500, or 7,500 feet.