Complete Specification of Simulation of Weight off wheel condition for armament checks

1 Title of the invention 3
2 Field of invention 3
3 Use of invention 3
4 Prior art 3
5 Draw backs of prior art 3
6 Comparison between prior scheme and present invention 4
7 Aim of the invention 4
8 Summary of the present invention 4
9 Brief description of Drawings 4
10 Statement of invention 5
11 Detailed description of invention 5
12 Drawings & worked examples 6

1. Title of the invention
Simulation of Weight off wheel condition for armament checks.

2. Field of invention
It is an electrical scheme, which offers a more efficient way to carryout armament checks on aircraft.

3. Use of invention
This invention finds its applicability in any fighter/trainer aircraft. Compared to the prior scheme, this scheme facilitates armament checks to be carried out without jacking up the aircraft (i.e putting aircraft on jacks)

4. Prior art
As per the fighter aircraft safety standards, Armament checks on a fighter aircraft can be carried out only if weight off the wheel "TRUE" condition is realized. In conventional method, to enable armament checks on ground weight off the wheel 'TRUE" condition has to be realized. For this purpose, aircraft was required to be jacked up.

5. Draw backs of prior art
In order to carryout armament checks, weight off wheel condition was required to be simulated. This was achieved by putting aircraft on jacks. This had mainly 3 drawbacks:

(a) Jacking up is a cumbersome activity involving significant manhours. Minimum 3 personnel are required taking a time of approximately 1 hour.

(b) In naval version, jacking up is much more difficult as it has to be done on deck.

(c) Jacking up setup causes hindrance to the working personnel.

6. Comparison between prior art and present invention
Prior art: In order to carryout Armament checks, Weight off wheel condition "TRUE" had to be realized. Hence jacking up of aircraft was required. This activity was quite cumbersome and time consuming, where minimum 3 working personnel were required to do the activity. In naval version of aircraft, it is not possible to jackup the aircraft on deck.

Present Invention: This invented scheme enables to simulate Weight off wheel condition by just using a switch in the Maintenance Panel. Hence there is a tremendous saving in manhours by this scheme. This scheme will be very useful for naval versions of aircraft, where jacking up of aircraft is very cumbersome.

7. Aim of the invention
Aim of the invention is to eliminate the necessity of jacking up the aircraft for carrying out the armament checks.

8. Summary of the present invention
This invented scheme provides a scheme to carryout armament checks with the help of just a switch. In this scheme, Override Switch is wired in the maintenance panel with two positions- NORMAL and OVERRIDE. As these checks are extremely critical, care has been taken to prevent inadvertent operation of the switch. Switch is provided with a switch guard, which ensures that the switch is guarded in NORMAL position by default. To carryout the armament checks, switch should be put in OVERRIDE position. In this position, weight off the wheel condition gets simulated and voltages are made available for armament checks. This scheme provides a simplified way to carryout armament checks by avoiding the complexities involved in jacking up the aircraft.

9. Brief description of drawings
Fig-l shows the existing wiring scheme as well as the new scheme with a new switch in the maintenance panel.

Existing Scheme: Power supply for armament checks is currently wired through Weight off wheel relays. When armament checks are to be carried out on ground, aircraft is put on jacks and weight off wheel condition is simulated. When Weight off wheel is TRUE, Weight off wheel relays get energized and allow the power supply to reach at armament points. In existing scheme as shown in Fig.l, armament checks (on ground) are possible if and only if Weight off wheel relays are energized i.e. only if the aircraft is put in jack up condition.

New scheme: Concept of this scheme is to simulate weight off the wheel condition by just using a switch in Ground maintenance panel (GMP). In this scheme, "Override Switch " is wired in maintenance panel with two positions- "NORMAL" and "OVERRIDE". As these checks are extremely critical, care has been taken to prevent inadvertent operation of the switch. Switch is provided with a switch guard, which ensures that the switch is guarded in NORMAL position by default. To carryout the armament checks, switch should be put in OVERRIDE position. In this position, a bypass path is provided and weight off the wheel condition gets simulated and voltages are made available for armament checks. This scheme provides a simplified way to carryout armament checks by avoiding the complexities involved in jacking up the aircraft.

10. Statement of invention
This invented scheme enables to simulate Weight off wheel condition by just using a switch in Maintenance Panel. Hence there is a tremendous saving in manhours by this scheme. This scheme will be very useful for naval versions of aircraft, where jacking up of aircraft is a cumbersome act.

11. Detailed description of invention
Refer fig-1. In Existing scheme, Power supply for armament checks is made available to armament check points through Weight off Wheel relays. Logic is such that relays are energized only when Weight off wheel condition is realized TRUE. During flight, Weight off wheel condition becomes true. In order to carryout armament checks on ground, it is required to simulate Weight off wheel condition on ground. For this purpose, jacking up of aircraft was mandatory. On jacking up the aircraft, WOW relays get energized and power supply is made available for armament checks.

However, this scheme had the drawback of requirement for jacking up of aircraft in order to simulate Weight off wheel condition. When aircraft is jacked up, the condition of Weight off wheel true gets simulated and voltage is made available for the armament checks.

In order to avoid the jacking up of aircraft, a bypass path is provided through a new switch WOW Override switch in the maintenance panel. Override Switch is wired in with two positions- NORMAL and OVERRIDE. As these checks are extremely critical, care has been taken to prevent inadvertent operation of the switch. Switch is provided with a switch guard, which ensures that the switch is guarded in NORMAL position by default. To carryout the armament checks, switch should be put in OVERRIDE position. In this position, a bypass path is provided and weight off the wheel condition gets simulated and voltages are made available for armament checks. This scheme provides a simplified way to carryout armament checks by avoiding the complexities involved in jacking up the aircraft.

Claims

1. This invention avoids jacking up the aircraft for armament checks by simulating Weight off Wheel condition.