DESCRIPTION

TECHNICAL FIELD

This invention describes a checking fixture to check the alignment of LCA engine third mount pin between the engine mount and the link assembly.

BACKGROUND OF INVENTION

LCA Engine is mounted oh aircraft using three mounting points such as Engine mount stbd, Mount bracket with swing grip and link assembly. Expandable pin will be used to mount the engine with link assembly. It is possible to carry out the inspection of proper mounting of the expandable pin between the engine mount and the link assembly only after installation engine on the aircraft. The link assembly has to be finalized in the detail stage as there would not be any accessibility after engine installation. In case of not matching, the entire assembly has to be rejected and to be initiated new manufacturing. It would not be affordable at that stage as it would hold up the assembly in jig till the new one is fabricated. Also, there is no guarantee that the newly manufactured assembly also would meet the requirement. Hence, there is a need for an alignment checking fixture to inspect the expandable pin without depending upon the installation of engine on the aircraft at final stage.

SUMMARY OF INVENTION

An alignment checking fixture is designed to simulate the actual condition of the engine third mount link assembly with expandable pin at detail stage. This checking fixture is to be used for checking of appropriate installation of the pin after applying the specified torque value given in the drawing.

DRAWINGS

Fig.l: Engine Mount Third Pin Checking Tool Drawing. Fig.2: Engine Mount Third Pin Checking Tool.

TOOL & PROCESS DETAIL DESCRIPTION

Alignment checking fixture consists of the following parts

1. Base Plate: It is used to support two numbers of L-Angle.

2. L-Angle: Two L-Angles are fixed on the base plate at the distance of 19.6 0.15/0 between them.

3. Bush: Two bushes are installed one on each L-Angle.

4. Dowel: It is used as a fastener to assemble L-Angle and base plate diagonally.

5. Allen Screw: It is used as a fastener to assemble L-Angle and base plate diagonally.

Note: Two L-Angles and base plate are set using Laser Tracker and assembled with the aid of Dowel and Allen bolt.

All the sharp edges has been rounded off to avoid the damage and injury while using the tool. Process to be carried out for checking the installation of the pin:

1. Place Alignment checking fixture on the working table.

2. Collect expandable Pin and the Link from stores.

3. The above mentioned items are positioned in the alignment checking fixture.

4. Required torque (not to exceed 250 Ib-in) is applied on the pin as per the drawing specification.

5. Pull the Pin horizontally to ensure proper gripping on the fixture.

6. If point (4 & 5) found satisfactorily LRU and Link are offered to inspection and sent to stores with tag.

7. If point (4 & 5) not found satisfactorily LRU and Link are sent for Rework.

Table-1

Material Schedule

CLAIMS

I We claim that the design and fabrication of Alignment Checking Fixture to inspect the alignment of third mount pin in LCATejas Aircraft.