During Starter Assisted airstart, what altitude range applies?

• A. Flight Level 210 to Sea Level
• B. Flight Level 230 to Sea Level
• C. Flight Level 190 to Sea Level
• D. Flight Level 250 to Sea Level

Answer: (A)

Starter-assisted airstart relies on external air to drive the turbine starter, and its effectiveness depends on air density, which decreases with altitude. For the CRJ-550, that method is practical up to Flight Level 210 (about 21,000 feet); below this, the air is dense enough to allow a reliable start, and above it the air is too thin for the starter to develop the required RPM, so a different start method would be used. So the applicable altitude range is from sea level up to Flight Level 210. Higher ceilings or ranges that go beyond 21,000 feet wouldn’t be appropriate for this start method.