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Module 17. Propeller

The limits for a tracking check are

  • 1/4 inch maximum difference between adjacent blades.
  • 1/8 inch maximum difference between opposite blades.
  • 1/8 inch maximum difference between all blades.

Explanation

Tracking tolerance limits how far the blade tips may run out of a common path, and the accepted limit is a maximum of one-eighth of an inch difference between all blades. Quoting the limit only between adjacent or opposite blades misstates the requirement, which applies across all blades.

ANGELA asking:

Isn't 1/16?

Community Comments (2)

S
Storklubba Posts: 1 17.03.2024 / 14:58
More input needed on this.
According to my book (aircraft technical book company module 17A, revision 001), "Each blade track should be
within 1/16 inch (plus or minus) from the opposite
blade’s track." I am unsure if this means 1/8" inch total.
I have an older book that indeed says maximum difference is 3 millimeter (1/8" inch).
C
CJThe3rd Posts: 4 20.02.2026 / 20:17
my notes say 1/16 for metal props and 1/8 for wood

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