For MMR operations above 20,000 ft, the system must be powered prior to _______ ft.

• A. 15,000 ft
• B. 20,000 ft
• C. 25,000 ft
• D. 30,000 ft

Answer: (B)

The main idea here is timing readiness of the MMR system with altitude. For operations above 20,000 ft, the system must be powered and ready by the time you reach that altitude so it can operate reliably in the high‑altitude environment, where power, thermal, and initialization conditions can differ from lower levels. Therefore, the required timing is to have the system powered prior to reaching 20,000 ft. If you wait until higher than that, you risk incomplete power-up or initialization when conditions have already changed. The other options don’t reflect this exact cutoff: powering well before 20,000 ft is earlier than required, while waiting until 25,000 or 30,000 ft would miss the mandated threshold.