1. Title of the invention

Test Instrument to test the Status of Landing Gear Uplock, Landing Gear Down Lock, Door Uplock & Door Open Limit.

2. Field of invention

The present invention pertains to an Aeronautical field, specifically dealing with Landing Gears & Doors.

3. Use of invention

It is an instrument used to verify,

a) Landing Gear Uplocks are in uplocked or unlocked condition

b) Landing Gear Down Locks are in down locked or released condition

c) Door Uplocks are in locked or unlocked condition

d) Door Open Limit is attained or not

4. Prior art

No automated instrument was used to test the status of Landing Gear Uplock, Landing Gear Down Lock, Door Uplock & Door Open Limit.

The checking was done manually. To check each switch, we had to insert pins or sockets inside the connectors and check the switch status using multimeter. One person was required to hold the connector and other used to connect the multimeter terminals to the inserted pins/sockets at the connector end.

5. Draw backs of prior art

The following are the drawbacks:

• Human Errors were noticed many times, when the multimeter contactors touch the connector shell. Hence the procedure lacked in accuracy.

• The time consumed per connector was between 10 min to 30 min depending on the accessibility of the connector. It takes almost a day to check all the connectors.

• More man power requirement. Minimum two persons were required, one person to hold the connector and the person to insert the pins/sockets & connect the multimeter probes.

• Some of the connectors were inside the rig area and lacked easy accessibility and proper lighting in certain areas. Connecting the right pins was a challenge, hence the person checking was not confident of the results.

• Logistics like multimeter, pins with pig tail and sockets with pigtail are required.

• The job was very tedious.

6. Comparison between prior art and present invention

7. Aim of the invention

The aim of the invention is to Design & Develop a simple, cost effective, efficient and a user friendly instrument to test the status of Landing Gear Unlocks, Landing Gear Down Locks, Door Unlocks & Door Open Limits.

8. Summary of the present invention

The Instrument is made from four mating connectors, one toggle switch, one push to test switch, LED's, resistors, diodes, batteries, battery holder, wires and a box housing these items.

This Instrument (Fig2) is a simple, compact, cost effective, efficient and user friendly to test the status of Landing Gear Uplocks, Landing Gear Down Locks, Door Uplocks & Door Open Limits.

Time required to resolve the snag is minimal. No logistics are required (i.e. multimeter, pins with pigtail/sockets with pigtail etc.)

This Instrument (Fig1) uses two AA batteries for powering the LED's. It sends a signal through each switch, when the switch is closed the return path is closed and LED glows. Each uplock has 2 or 3 switches and separate LED indication is provided for each switch.

The Instrument has a lamp test switch to ensure that all lamps are OK before the start of test.

9. Statement of invention

This Test Instrument has the following advantages

• This instrument is a simple, compact, efficient and a user friendly to test.

• The same instrument can be used for checking the status of Landing Gear Uplocks, Landing Gear Down Locks, Door Uplocks & Door Open Limits.

• Time required in resolving the snag is minimal.

• No Logistics is required (power supply unit, Digital multimeters, shorting links etc.)

• Single person can perform the testing.

• Any unskilled person with a little training can operate the instrument.

• The instrument uses 2 Nos of AA batteries, which works for 9 months to 1 year, hence power consumption is very less

Claims

We claim that

1. The invented Test Instrument is capable of testing the following

• Landing gear uplock status

• Landing gear down lock status

• Landing gear door uplock status

• Landing gear door Open limit status

The tester sends an electrical signal to the units. Based on the feedback received, the respective indicators will be lit.

2. Testing of each unit, claimed in claim 1 can be tested in less than 10 sees.

3. With this Instrument, single person can perform the testing accurately.

4. This Instrument is a simple, compact, efficient, cost effective and a user friendly gadget to test the status of Landing gear uplocks, Landing gear down locks, Door uplocks & Door Open limits.