FAA Instrument Rating Airplane (IRA)IFR Procedures and ChartsMedium
A pilot is filing an IFR flight plan for a route with a magnetic course of 250° at an altitude above 3,000 feet AGL, below 18,000 feet MSL. Under the IFR hemispheric cruising altitude rule, which altitude is appropriate?
- A9,500 feet MSL
- B10,500 feet MSL
- C8,000 feet MSL
- D7,000 feet MSL
Show answer & explanationAnswer & explanation
Correct answer: C. 8,000 feet MSL
For magnetic courses of 180° through 359°, IFR flights below 18,000 feet use even thousand-foot altitudes (with no 500-foot addition, since that applies only to VFR). A course of 250° falls in this westbound range, so 8,000 feet MSL is an appropriate even-thousand IFR altitude.
Why the other options are wrong
- A. The 500-foot addition applies only to VFR cruising altitudes, not IFR.
- B. 10,500 also includes an improper 500-foot addition; IFR uses whole even thousands for this course.
- D. 7,000 is an odd-thousand altitude, appropriate for eastbound courses (0°–179°), not 250°.
Hemispheric Cruising Altitude Rule
A rule assigning cruising altitudes based on magnetic course to reduce head-on traffic conflicts: odd thousands for 0°–179°, even thousands for 180°–359° (IFR, below 18,000 ft, no 500 ft addition).
- Applies to IFR flights below 18,000 feet MSL
- Odd thousands (3,000, 5,000, 7,000...) for courses 000°-179°
- Even thousands (4,000, 6,000, 8,000...) for courses 180°-359°
- VFR adds 500 feet; IFR does not
Memory trick: Odd East, Even West — no extra 500 for IFR guests.