Definition
A compressor blade tip designed with a thin, narrow outer edge so that if the blade contacts the surrounding compressor case during operation, the tip wears or burns away cleanly without damaging the rest of the blade or the case. The reduced cross-section at the very tip is sacrificial — it lets the blade rub momentarily against the case material, producing a brief high-pitched noise (the 'squeal') while preserving blade integrity and maintaining tight tip clearance for compressor efficiency.
Plain English
The very edge of the compressor blade is made deliberately thin so that if it touches the inside of the engine case while spinning, only that thin edge wears away. This protects the rest of the blade and keeps the gap between the blade and the case as small as possible, which helps the engine run efficiently.
Context Anchor
Seen during gas turbine compressor blade inspection, especially when checking blade-tip clearance, rubbing marks, or compressor case wear.
Derivation
Named for the high-pitched squealing sound the blade tip makes when it briefly rubs against the compressor case. The term is descriptive — the noise itself signals the tip is doing its job by wearing rather than transferring damage to the case or the main body of the blade.
Why Pilots Care
Correct clearance at the squealer tip preserves compressor efficiency, reduces fuel burn, and prevents progressive blade damage that can lead to engine surge or failure.
Intuition Check
A squealer tip is not installed to make noise. The name points to a blade-tip shape that works very close to the compressor case and may show evidence of rubbing.
Example Sentence 1
During inspection, the technician noted minor wear on the squealer tips, consistent with normal break-in contact between the blades and the compressor case.
Example Sentence 2
Excessive wear on the squealer tips required replacement of the affected rotor blades before the engine could return to service.