Why are loose-fitting blades used on the first several stages of large axial compressors?

Correct Answer: Option B — To minimize vibration while the engine is passing through critical speed ranges.

Loose-fitting blades, often referred to as 'shrouded' or 'damped' blades, allow for slight movement within the root attachment. This mechanical freedom provides damping characteristics that absorb energy and minimize resonant vibrations as the engine accelerates through critical speed ranges, preventing fatigue failure of the compressor blades during operation.