S.No. Content Sheet No

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 art and present invention 3

7 Aim of the invention 4

8 Summary of the present invention 4

9 Brief description of drawings 4

10 Statement of invention 4

11 Detailed description of invention 5

12 Drawings & worked examples 5

1. Title of the invention

Powering Scheme of a two seater fighter/trainer aircraft during solo flight.

2. Field of invention
Electrical Circuit logic for a two seater fighter/trainer aircraft.

3. Use of invention
This circuit logic can be implemented in any two seater fighter/ trainer aircraft.

4. Prior art
In any two seater fighter/trainer aircraft, two pilots will fly the aircraft. In such a case both the cockpits will be powered . In case the aircraft is flown in solo configuration i.e, single pilot, even then both the cockpits will be powered and all the indications will be "on" in the rear cockpit although there is no pilot in the rear cockpit.

Switch controls are available in both cockpits. Usually the rear cockpit is occupied by the trainer. Hence all the main controls will be held by the trainer. These main controls (switches) will have two positions. One position will be designated as" Front" and the other will be designated as "off" or "on" as per the system requirement. Once the rear pilot gives authorization (by changing the switch to the "front" position), only then the front pilot can operate the controls in the front cockpit. During solo flying, the ground crew and also the pilot has to ensure that all the controls in the rear cockpit are in the correct position (front)before the pilot enters the cockpit.

5. Draw backs of prior art

During solo flying, the rear cockpit displays and indications will be powered which leads to unnecessary waste of aircraft power.

During solo flying, it becomes mandatory for the ground crew and the pilot to check the position of all the switches in the rear cockpit before entering the cockpit. If the switches are not in the correct position in the rear cockpit, the pilot will not be able to operate the controls which could lead to a dangerous condition.

6. Comparison between prior art and present invention

In the present scheme, a switch is provided in the front cockpit. The switch is designated as single/twin switch. The switch has two positions " single" and "twin". In the "twin" mode all the controls are available in both cockpits. In the "single" mode all the rear displays and indications are powered off and all the controls are with the front pilot irrespective of the position of switches in the rear cockpit.

7. Aim of the invention
Aim of the invention is to provide a powering scheme for a two seater fighter/trainer aircraft with the following features:

1. Conserve power when flying in solo mode

2. Reduce the workload of the ground crew and the pilot.

3. Eliminate the errors which could lead to dangerous condition.

8. Summary of the present invention

In this scheme, all the rear indications and displays are automatically switched off once the " Single/twin" switch in the front cockpit is put in "single" mode. Also there is no need to ascertain the position of the switches in the rear cockpit by the ground crew or the pilot as the " Single/Twin" switch will override all the switch positions in "single" mode.

9. Brief description of drawings
Fig-1 shows the powering scheme of cockpit Displays for both front and rear cockpit. The power supplies for the rear cockpit are routed through the relays which in turn are controlled by the Single/ Twin Switch. When the switch is selected to" Single" mode, the relays are energized and the power supply to the rear cockpit is cutoff.

Fig 2 shows the schematic drawing for an actuator. This actuator has two controls, one in the front cockpit and the other in the rear cockpit. The power for the rear cockpit is routed through the Single/Twin switch in the front cockpit. During solo flying, the single/twin switch is in "single" mode. In this case the rear switch position is bypassed and power is available at the front control switch.

10. Statement of invention
This scheme conserves power in a two seater fighter/trainer aircraft when flying in solo mode. It also reduces the workload of the ground crew/pilot as the status of the switch need not be checked when flying in solo mode. It eliminates errors caused by leaving the switch in the incorrect position.

11. Detailed description of invention
Refer fig-1. Shows the powering scheme for cockpit displays. The power supply for the front cockpit is routed directly. The power supply for the rear cockpit is routed through a relay R1. This relay R1 is controlled through Single/Twin switch. The SingleATwin Switch is provided in the front cockpit. In the " Twin" mode, Power is available for both the front and rear cockpit displays. In case of solo flying, the switch is put in "single" mode. In this case relay R1 is energized and the power supply to the rear display is cutoff. Similar scheme can be adopted for all the displays and the indicators in the rear cockpit.

Refer Fig 2. Shows the powering scheme of actuator. There are two switches, Actuator Control Switch -S1 in the front cockpit and Actuator Control Switch-S2 in the rear cockpit. A single /twin switch- S3 is provided in the front cockpit.

During normal flying i.e, 2 seater mode, pilots will be seated in both the cockpits. In such a case, Switch S3 will be put in "Twin" mode. The switch S2 (in rear cockpit) will be put in " front" position. Under this condition the front pilot will control the actuator. In case the rear pilot want to switch off the actuator he changes the position of S2 to "OFF" mode. The front pilot will have control only when the rear pilot gives him authorization by putting the switch in u Front" position.

In case of "solo" flying, there will be only one pilot who will occupy the front cockpit. Under such a condition, it has to be ensured that the switch S2 in put in "Front" mode. This will have to be ensured by the ground crew & the pilot before he enters the cockpit. Only then the front pilot will be able to control the actuator. In case the switch is left in " OFF" position, the front pilot will not be able to control the actuator. This could be a dangerous condition. To avoid such a condition, the single /twin switch- S3 is provided. Once this switch is put in "single" mode, the rear switch S2 is by passed and power is available to the front switch S1 directly. Hence the position of the rear switch need not be checked during solo flying.

This scheme can be adopted to all the controls which are available in both front and rear cockpit.

Also the Single /Twin switch shown in Fig1 and Fig2 are one and the same.i,e there is any one single/twin switch provided in the front cockpit. All the circuits can be linked to this single/twin which will carry out all the above described functionality.

12 Drawings & worked examples

Fig-1 & Fig-2 show the powering scheme for displays and actuators respectively.

Claims
1. This scheme conserves aircraft power in a two seater fighter/trainer aircraft when flying in solo mode.

2. It eliminate errors caused by leaving the switch in the incorrect position in the rear cockpit

3. This scheme reduces the workload of the ground crew as well as the pilot as
the position of the switches in the rear cockpit need not be checked before flight.