Complete Specification

Arrestor Hook Actuation System for Navy Aircraft

S.No. Content Sheet No
1 Title of the invention 3
2 Field of invention 3
3 Use of invention 3
4 Brief description of drawings 3
5 Detailed description of invention 3
6 Drawings & worked examples 4

1. Title of the invention

Arrestor Hook Actuation System for Navy Aircraft

2. Field of invention

It is an Electrical and Hydraulic/Mechanical engineering design used for actuation system for navy aircraft arrestor hook system.

3. Use of invention

This invented integrated system finds its applicability in the navy aircraft which are to be operated on ship.

4. Brief description of drawings

Fig-l shows the Hydraulic Schematic/circuit of the arrestor hook system. Fig-2 shows the Electrical schematic of the arrestor hook system.

5. Detailed description of invention

Refer fig-l & 2. When arrestor hook is selected "UP", the electro selector connected to Hydraulic System-Normal is energized to pressurize the actuator cum damper as well as the up-lock assister jack. The arrestor hook retracts and the up-lock engages automatically with the up-lock pin mounted on the arrestor hook. Once indication is obtained on the up-lock the electro selector is de-energized electrically. Arrestor hook shock absorber exerts down load of required amount on the up-lock.

When the arrestor hook is selected down the electro selector connected to Hydraulic System-Normal is energized to pressurize the up-lock normal port and the up-lock is unlocked and arrestor hook extends. Micro switch mounted on platform senses extension of arrestor hook.

In case of emergency Hydraulic System-Normal is not available, the arrestor hook switch is selected to Emergency hook down and up-lock is unlocked through Hydraulic System-Emergency by energizing the emergency selector.

Hydraulic Normal retraction line is connected to retraction through a restrictor to ensure that the jack up lines are vented to return line even in case of failure of electro selector in struck open position. An interlock to avoid inadvertent normal/emergency operation on ground is provided through nose undercarriage weight-on-wheel microswitch.

We Claim that:

1. A reliable electrical-hydraulic circuit which addresses all the requirement of the arrestor hook actuation system for deck landing of a naval aircraft.

2. Redundancy and ground inadvertent operation interlocks are built in.

3. With the configured system Normal and emergency operation of arrestor hook is ensured.

4. The Arrestor Hook can be extended even when the normal operation electro selector is stuck/failed in the retracted position.