Material Screw Testing ON Tail Rotor Drive Using 'D' Penetrant Testing Method

Non Destructive Testing is a method of inspection that used in aircraft maintenance. Penetrant test is one type of Non Destructive Test (NDT) which is applied to screw tail rotor drive material. The purpose of this study was to determine the presence of defects, cracks, or other discontinuities without damaging the object being tested or inspected. The design research of applying the penetrant test to screw tail rotor drive material containing ferrous (fe) used the 'D' method, which is by dipping the material into the penetrant liquid with a waiting time of 20 minutes, then cleaning it using water and an emulsifier and drying using an oven. Before the inspection is carried out, the material is sprayed with a developer with a waiting time of 10 minutes, then the material is checked for defects or not. The test results showed that there was no defect in the form of a crack, but found an indication that is included in the non-relevant indication, which is an indication of the shape or design of the material found in the screw section.


INTRODUCTION
In the aviation industry equipment with solid good material automatically uses machines and those that still use human power, cannot be separated from the problem of physical defects or damage that has occurred inside the product.Physical defects that occurs on a large and deep scale maintenance activities will have an impact on financial losses even create a danger to the safety of workers or users of product.The physical defect that resides in solid matter is of course not can be known from direct sight so it is necessary do an inspection of an object to see whether there is or whether or not defects that occur in solid objects.The  Penetrant test is a method with using color dye to see surface cracks.The technique is based on capillarity action with the ability of a liquid to be drawn into a 'clean' surface breaking flaw [5].Penetrant is also applied to the check part by dipping, spraying or brushing [6].Penetrant test used to verify open discontinuities at the surface of inspected [7], [8].Penetrant test also detect individual parts, combine surface, material is easy to filter into the inside, and that can't be cleaning [9].The spray can't be used to detect cracks for a local test in the critical part [10].removal, part must be cleaned and reprocessed [11].

RESEARCH METHOD
The research used experiment method    The steps of D penetrant test are: 1. Quality Performance This step for controlling to ensure that materials and equipment which are used in penetrant system is acceptable.
For facilities that operate less frequently, check frequency daily and weekly can be reduced, but must be done before inspection.Other checks must be carried out at the same frequency like for full time inspection [11].

Cleaning
Before the test, the procedure that must be done is the cleaning process material manually using Methyl Ethyl Ketone (MEK), the purpose of cleaning this material is to remove dirt or oil that is on the surface of the material which can affect indication of the test to be performed.adhering to the surface of the material.In this process pay attention to the material carefully so that there is no over-wash, if over-wash, the indication that will be checked will be wasted and make the material have to be cleaned again and on process reset.
inspection carried out in the industrialized world without destroying the solid objects that are regularly inspected called the Non-Destructive Test.Non-Destructive Test (NDT) is defined as a physical evaluation of a solid object under test.NDT is used mainly in industry to detect defects, cracks and voids in materials used in various structures with different materials its kind.In NDT there are four basic NDT methods with name: (1) magnetic particle inspection (MT); dye penetrant inspection (PT); radiographic inspection (RT); and (4) ultrasonic inspection.Type of NDT methods have advantages and disadvantages of each.For example, the advantages of Penetrant Testing (PT) are: simple to use, inexpensive, quick results, can be used on any non-porrous material, portability, low operator skill required.
Excess penetration is eliminated by water washing (A method), emulsification hydrophilic (B Method), lipophilic emulsification (C Method), or solvent cleaner (D Method).The penetrant must remove from the surface without removing from the inside discontinuity.The optimal number of washes must be obtained.Too slight washing will cause a penetrant background redundant and the indication will not be indistinguishable from the part surface.If too much is removed from the discontinuity, the indication is weak or no indication will be formed.The process of 'D' Penetrant testing method is similar to B method water based emulsifier uses detergent action to removes penetrant on the surface.This is possible perfectly cleanses the surface and enhances contrast for inspection.The optimum emulsification time must be determined experimentally for specific application.The emulsifier concentration for the spray method is limited up to 5%.The concentration level of the immersion method can vary from 5% up to 35% depending on the manufacturer.Emulsion waiting time should not be more than 2 minutes.After application of the hydrophilic emulsion, the components will be checked should be rinsed with water.In case of over-Volume 6, Number 1, May 2021 ISSN 2528-2611, e-ISSN 2528-2700 and was conducted for two months, starting from May 2020 to July 2020 in PT.Dirgantara Indonesia.The material testing is screw on tail rotor drive shift super puma aircraft with part number 332A34 -1104 -22.The test method used the D method emulsifiable, hydrophilic penetrant testing.Sensitivity level 4 -Ultrahigh with developers form D -Nonaqueous for type I fluorescent penetrant.

Table 1 .
Tools and materials