Jet route altitudes start at what altitude and go up to what flight level?

Jet route altitudes start at what altitude and go up to what flight level?

• A. 18,000 MSL; FL450
• B. 10,000 MSL; FL180
• C. 20,000 MSL; FL600
• D. 0 MSL; FL200

Answer: (A)

Jet routes are the high‑altitude IFR corridors designed for jet traffic. They start at 18,000 feet above mean sea level and extend up to flight level 450 (45,000 feet) under standard pressure. This range reflects the transition from feet MSL to flight levels as you climb, and it provides efficient, well‑separated airspace for high‑speed aircraft. Below 18,000 feet, other routing like Victor airways applies, so the jet route system doesn’t start lower than that. The other ranges don’t fit because they either start too low or end too high for the jet route structure.

Jet routes are the high‑altitude IFR corridors designed for jet traffic. They start at 18,000 feet above mean sea level and extend up to flight level 450 (45,000 feet) under standard pressure. This range reflects the transition from feet MSL to flight levels as you climb, and it provides efficient, well‑separated airspace for high‑speed aircraft. Below 18,000 feet, other routing like Victor airways applies, so the jet route system doesn’t start lower than that. The other ranges don’t fit because they either start too low or end too high for the jet route structure.