Max N1 (Red) for the CRJ-550 is what percentage?

Max N1 (Red) for the CRJ-550 is what percentage?

• A. 99.0%
• B. 99.5%
• C. 100%
• D. 98.5%

Answer: (B)

N1 is the low‑pressure spool speed, shown as a percentage of its reference speed, and the red segment on the N1 gauge marks the limit you must not exceed. For the CRJ‑550, the redline is set at 99.5% to provide a small safety margin above the actual limit and to account for sensor tolerances and engine control behavior. That’s why 99.5% is the maximum N1 in the red band—pushing beyond it could approach an overspeed condition. Values like 99.0% or 98.5% are simply below the published redline, and 100% would imply hitting the limit that the redline aims to protect against.

N1 is the low‑pressure spool speed, shown as a percentage of its reference speed, and the red segment on the N1 gauge marks the limit you must not exceed. For the CRJ‑550, the redline is set at 99.5% to provide a small safety margin above the actual limit and to account for sensor tolerances and engine control behavior. That’s why 99.5% is the maximum N1 in the red band—pushing beyond it could approach an overspeed condition. Values like 99.0% or 98.5% are simply below the published redline, and 100% would imply hitting the limit that the redline aims to protect against.