P&W recommends that all initial test cell vibration
monitoring include measurement and recording of
engine overall vibratory output during the engine
vibration survey acceleration and deceleration.
This initial vibration survey should be used to
define the engine vibration peaks and their
frequencies, which must be further defined through
steady state analysis.
1 When vibratory output is measured in overall
units only (no rotor related analysis is
conducted), applies.
2 When a rotor related analysis is conducted and
conditions 1. and 2. of paragraph (e) (below)
are both met, then the maximum overall level of
1.8 inches (45.7 mm) per second (peak) applies.