Can any body help me urgenly the following questions?what is SOAP? 2 SSID? 3 TURBINE SHAFT DRIVE? FEATHERING?

Question

what is RESONANCE FREQUENCY? FREQUENSY HEADACHE?

Answer 1

well, feathering refers to the process of turning the propeller blades to a high angle (75 degrees or more) of pitch, reducing drag in the event the engine fails.

This is important because a propeller attached to a failed engine which has been left to "windmill" will dramatically increase drag, as opposed to a feathered propeller. So, windmilling and feathered can be considered practical opposites.

Some propellers also feather as part of the normal shutdown.

Answer 2

Spectrometric oil analysis program (SOAP)--the mechanic periodically sends in a sample of the engine oil for analysis.

Tower shaft drive?

Feathering is streamlining the propeller blades to reduce drag.  Some propellers can be fully feathered, some can be moved to a low drag position, and some can not be feathered at all.

Answer 3

SOAP was properly answered by MARK

FEATHERING was properly answered by Aaron K

SSID - this is a maintenance program on top of the standard MPD driven tasks, it stands for Supplemental Structural Inspection Document

Turbine Shaft Drive - I'm not sure you got your nomenclature right on that one. That could be two things:

1) The shaft that the turbine wheels are mounted on

2) The drive unit to an accessory gear box (driven by the turbine shaft)

Resonance Frequency - that is the natural frequency that a given object will resonate at (often producing a "standing wave")

Sounds like you ought to study for your classes rather than asking for help here in this forum.