DESCRIPTION

TECHNICAL FIELD

The invention describes the process for fabrication and installation of Adapter Assemblies on LCA Tejas

Aircraft.

BACKGROUND OF INVENTION

When number of components made up of Pipe and Machined Components are being welded together without proper fixture, it is natural that distortion will happen. Such distortion will lead to improper welding and misalignment of its position on Aircraft build up. This invention is to fabricate the Adapter assemblies without distortion.

SUMMARY OF INVENTION

A distortion of 3 to 5 mm was measured on Adapter Assemblies (Fig. 2) after welding operation due to welding of various components. This invention/process gives the procedure to fabricate Adapter Assemblies without any distortion as per drawing.

DRAWINGS

Fig.l: Model and Drawing of l/B Adapter assembly

Fig. 2. Mandrel for drilling Adapter assembly and weld assembly

Fig.3: Position of drill template on component to drill pilot holes.

PROCESS DETAIL DESCRIPTION

Wing assembly of LCA-Tejas Aircraft is acting as a fuel storage area. Drop Tank is another external fuel storage area which can be fixed with Wing assembly whenever required. Adapter assemblies are acting as a transfer media to transfer fuel from Drop tank to Wing Assembly and then will be send to Aircraft Engine. There are 2 Nos of Adapter assemblies positioned on Wing Structure at l/B and O/B area. 1 No of Adapter assembly will act as pressurizing media to give pressure to Droptank and another 1 No of Adapter assembly will act as a transfer-media to transfer fuel from Drop tank to Wing assembly and then it will be send to Engine.

An adapter assembly consists of following parts (Fig. 1):

1). Adapter,

2). Fittings and

3). Pipes.

These parts are to be assembled by means of welding operation. Earlier these parts were assembled using mandrel (Fig.2) which was not able to meet as per drawing requirement and more rework was carried out to finalize assembly. Weld Jig made available to carryout welding operation for fabrication of Adapter assemblies. The base and supports for positioning Adapter, fittings and pipes of jig are made up of Steel for distortion free welding operation and rigidity. Hence procedures made available to fabricate Adapter assemblies as below.

1). Position Adapters (1/B and O/B) on jig (Fig.3) along with Fittings and Pipes,

2). Lock all parts of on jig by its locators,

3). Ensure its freeness and its position correctly,

4). Tack weld Adapter with Fittings and then Fittings with Pipes,

5). Carryout welding all around the mating area as per drawing,

6). Send it for its final finishing operations,

7). Installation of Adapter assemblies on Wing Bottom Skin after position correctly, drilling and Fastening operations.

After carryout the full welding operation it is found that, the Adapter assemblies are made as perdrawing and suiting on assembly as per drawing requirement without any rework.