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【范围】
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1.1 Purpose
This specification details requirements and procedures for the detection of defects in aircraft and engine components
during maintenance and overhaul operations.
1.1.1 This specification contains three appendices which provide additional guidance designed to supplement the
information contained in the main body of the document. Because the guidance contained in the appendices is
either subjective in nature or may have alternative acceptable approaches, it is not intended to be binding unless
specifically invoked by the cognizant engineering organization (CEO), an original equipment manufacturer (OEM),
or other contractual agreement. Personnel performing inspections to this specification should be familiar with the
guidance and exercise good judgment if variance from this guidance is necessary. The following appendices are
included:
1.1.1.1 Appendix A - Guidelines for Design, Procurement and/or Fabrication of Penetrant Systems
1.1.1.2 Appendix B - Guidelines for Assessment of Background Fluorescence
1.1.1.3 Appendix C - Processing and Inspection of Drum Rotors/Deep Well Spools and Other Complex Parts w/Limited
Accessibility
1.2 Processing of parts and interpretation and evaluation of indications revealed by this inspection process shall be
accomplished by qualified personnel having experience with fluorescent penetrant inspection. Qualification of
personnel shall be in accordance with ATA 105, MIL-STD-410, NAS 410, EN 4179, or ASNT SNT-TC-1A.
1.3 Basis of Application
This process has been used typically by maintenance and overhaul facilities to inspect aircraft and engine components
and associated accessories when fluorescent penetrant inspection is specified, but usage is not limited to such
applications.
1.3.1 There are areas in this document that may require specific direction from the OEM or CEO. This direction shall be
provided in the part material specification for each part (See 7.2.48) in the following areas:
1.3.1.1 Etching Requirements
If not specified, etching will not be performed (See 3.3.6).
1.3.1.2 Cleaning Requirements
If not specified, solvent cleaning using Alcohol, Acetone or Methyl Ethyl Ketone (where locally approved) (See 3.4) or an
approved QPL-AMS-2644 solvent cleaner/remover is acceptable.
1.3.1.3 Surface Coating Removal
If not specified, parts may be inspected with the surface coating intact (See 3.3.4 and 3.3.4.1).
1.3.1.4 Penetrant Sensitivity Level
If not specified, Sensitivity Level 3 penetrants shall be used on all airframe hardware and components and Sensitivity
Level 4 penetrants shall be used on all Major Rotating components of engines and Auxiliary Power Units (See 7.2.29).
1.3.1.5 Penetrant Method
If not specified, Type I, Methods A, C, or D may be used except for major rotating engine hardware which shall only be
inspected using Type I, Methods C or D.
1.3.1.6 Drying
If not specified, air-circulating oven drying shall be used. If other heat-assisted drying methods are used, they shall be
approved by the CEO.
1.3.1.7 Developer
If not specified, dry developer (form a) shall be used.
1.3.1.8 Inspection Coverage
If not specified, the areas described in 3.4.12.1 shall be inspected. If inspection of areas requiring special equipment or
techniques (i.e., UV borescopes or light sources, special material application or removal devices, part handling fixtures,
part masking, etc.) is necessary, detailed instructions shall be provided by the OEM part or material specification. When
specific areas of parts require intensified inspection scrutiny, due to either their critical nature or past history of failure, this
information shall be included in the repair or inspection manual or document.
1.3.1.9 Post-Inspection Cleaning
If not specified, parts shall be cleaned and dried after inspection to remove inspection residue which may be detrimental
to subsequent operations or impair the structural or functional integrity of the part.
1.3.1.10 Processing Parameters
Shall be as specified within this document. If approved by the OEM, different processing parameters, other than those
specified herein, may be used.
1.3.1.11 Acceptance Criteria
This specification does not provide accept/reject criteria for specific components. Where no accept/reject criteria are
specified by the CEO, all relevant indications shall be regarded as suspect and shall not be accepted without review by
the CEO.
1.4 Classification of Penetrant Systems
1.4.1 Applicable fluorescent penetrant systems are classified into the following Types, Methods, and Sensitivity Levels:
Type I - Fluorescent dye
Type II - Visible Dye (not applicable to this specification)
Method A: Water-Washable
Method B: Post-Emulsifiable, Lipophilic
Method C: Solvent Removable
Method D: Post-Emulsifiable, Hydrophilic
Sensitivity Level 2: Medium
Sensitivity Level 3: High
Sensitivity Level 4: Ultra-high
1.4.2 Applicable developers are classified into four forms.
Form a Dry Powder Developer
Form b Aqueous Soluble Developer
Form c Aqueous Suspendable Developer
Form d Nonaqueous Wet Developer (NAWD)
1.5 Safety - Hazardous Materials
While the materials, methods, applications, and processes described or referenced in this specification may involve the
use of hazardous materials, this specification does not address the hazards which may be involved in such use. It is the
sole responsibility of the user to ensure familiarity with the safe and proper use of any hazardous materials and to take
necessary precautionary measures to ensure the health and safety of all personnel involved.
1.5.1 Safety Precautions
Protective clothing, including eye shields, suitable gloves, and aprons should be worn when filling tanks or when there is a
possibility of splashing or overspray. Tanks should be covered when not in use and should be operated with adequate
ventilation for fume extraction. Operating instructions from the manufacturer of the system employed together with local
workshop regulations shall be followed.strRefField
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