What is the recommended rate of descent if you need to lose altitude rapidly at a groundspeed of 400 knots?

In aviation, the rate of descent required to lose altitude rapidly is influenced by the aircraft's groundspeed. When flying at a groundspeed of 400 knots, achieving a quick descent becomes critical, especially in scenarios like emergency descents or maneuvering for a controlled landing in response to urgent situations.

A rate of descent of 2000 feet per minute (fpm) is generally considered effective for such high groundspeeds. This descent rate allows for a significant altitude loss while maintaining control of the aircraft and optimizing safety measures during the maneuver. The calculation is typically based on achieving a balance between descent rate and airspeed, where a higher descent rate is acceptable due to the increased groundspeed.

Descent rates lower than 2000 fpm may not be sufficient to ensure that altitude is lost quickly enough to manage the flight dynamics effectively at 400 knots. Therefore, the recommendation to use a rate of 2000 fpm aligns well with operational standards for safety and efficiency during rapid descents in high-speed scenarios.