Title of the invention

Invention of re-inforcement stiffener for the external under carriage door operating switch access door for deep penetrating fighter aircraft.

Field of invention

This invention is related to the manufacturing, repair Procedure and quality assurance of newly fabricated re-inforcement stiffener for the external under carriage operating switch access door for deep penetrating fighter aircraft.

Use of invention

This invention is used to Prevent frequent Damages to the deep penetrating fighter Aircraft external under carriage operating switch access door due to aero dynamic forces during flights.

Prior art

This method is unique. There was no previous method available for the repair. Frequent damages were found like warpage / cracks and canning. Since there is no repair scheme available for this access doors, the access door is rejected which leads to replacement of damaged door with new doors.

Draw backs of prior art

Complete rejection of access door due to oil canning/ warpage.
Comparison between prior art and present invention

In the prior art ,complete rejection of access door due to oil canning / warpage and replacing new access door.

Name of the Applicant: Hindustan Aeronautics Limited, Overhaul Division. Sheet No: 4

Application No.: Total Sheets: 9

In the present invention repair scheme for the rejected access door due to oil canning eliminates the rejection of the access door.

Aim of the invention

Aim of the invention was to develop an effective and efficient repair scheme to prevent frequent damages / warpage to the deep penetrating fighter Aircraft external under carriage operating switch access door due to aero dynamic forces and Vibrations during flights.

Summary of Present Invention

This Invention of repair scheme is used in deep penetrating fighter aircraft. The repair scheme is used in under carriage operating switch access door. The Operating Switch of Under carriage is situated in the port side below the air duct of center fuselage. The switch is used for the manual operation of under carriage doors during the system checks and flight release. The operating switch is placed in a separate housing and is closed by access panel door.

The access panel door is undergoing frequent warpage / dent due to aero dynamic forces and vibrations during flight and has lead to the chances of complete panel flown-off of the during flights. Flying- off of the access door is a potential flight safety hazard.

This invention is related to develop an effective and efficient repair scheme to prevent frequent Damages to the deep penetrating fighter Aircraft external under carriage operating switch access door due to aero dynamic forces and Vibrations during flights.

Brief Description of Drawings. FIG.l Location of the access Panel.

FIG.2 Illustrates a metallic access panel door.

FIG. 3 Illustrates the dented access panel door.

FIG. 4 Illustrates Hand Sketch of Reinforced access panel door.
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Signature of the Inventor Signature of the Applicant
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Name of the Applicant: Hindustan Aeronautics Limited, Overhaul Division. Sheet No: 5
Application No.: Total Sheets: 9

Statement of invention

This invention is related to the manufacturing, repair Procedure and quality assurance of newly fabricated re-inforcement stiffener for the external under carriage operating switch access door for deep penetrating fighter aircraft

Detailed description of invention

a) Access panel door 1 is removed from the aircraft and dents were removed.

b) Aluminum alloy Joggle plate (inner portion of the door) in accordance with the contour available in the access panel is prepared using chemical milling 2.

c) Two number of "L" angle 10 x 10 x 1.2 mm and 125 mm length is fabricated 3.

d) One number of "L" angle 10 x 10 x 1.2 mm and 90 mm length is fabricated 4.

e) Joggle plate along with "L" angle is riveted to the Access panel door using 3.2 CSK rivets Qty.14 Nos.

Signature of the Inventor Signature of the Applicant

Claims We claim

Method for providing re-inforcement using Stiffeners for the External Under Carriage Door operating switch access door.

Selection of "I" angle stiffener of different size to match the inner contour of the access door.
Selection of rivets for fastening "L" Angle stiffeners to access panel door as per design intent.