What is the maximum allowable descent rate in feet per minute before exceeding the structural limits?

The maximum allowable descent rate before exceeding the structural limits of the CRJ 900 is indeed 3,000 feet per minute. This limitation is crucial for ensuring the integrity of the aircraft's structure during rapid descents. Exceeding this rate could lead to undue stress on the airframe, potentially causing structural damage or failure.

Aircraft are designed with specific operational parameters that account for the forces experienced during various phases of flight. Adhering to this maximum descent rate helps maintain safety and prolongs the aircraft's lifespan. It's essential for pilots to be aware of such limitations as they are critical for safe operation, especially during approaches and landings.