Inflatable device for emergency aircraft buoyancy

1. An inflatable device for aircraft buoyancy, configured to be inflated in case of emergency landing on water, the device comprising:

a first inflatable chamber configured to be inflated from a source of gas, to change from a folded state to an inflated stated,

a plurality of second inflatable chambers, each configured to be supplied from gas flowing in the first chamber, via at least one supply passage, each supply passage being arranged directly in a wall separating the first inflatable chamber from the respective adjacent second inflatable chamber, each second inflatable chamber configured to be inflated to change from a folded state to an inflated stated, wherein each supply passage comprises a check valve.

2. The device according to claim 1 , wherein each supply passage comprises a calibrated orifice.

3. The device according to claim 1 , wherein the first chamber is coupled to a source of gas under pressure via a selectively controlled valve.

4. The device according claim 1 , wherein there is provided a main envelope forming an outer wall of the seconds chambers at inflated state and the first chamber is housed within the main envelope.

5. The device according to claim 4 , wherein each second chamber is adjacent to two neighboring other second chambers.

6. The device according to claim 5 , wherein each second chamber is separated from two neighboring second chambers by partition walls, each second chamber being delimited radially outwards by the main envelope, sidewise by two partition walls, and radially inwards by the first chamber.

7. The device according to of claim 1 , wherein the first chamber is elongated and extends substantially in a longitudinal direction.

8. The device according to claim 7 , wherein the first chamber is tubular when inflated.

9. The device according to claim 1 , wherein there is provided a main inlet port at the first chamber and said inlet port is located in axial position, namely at one axial end of the device.

10. The device according to claim 7 , wherein the supply passages are each at different axial positions along the longitudinal direction.

11. The device according to claim 1 , wherein a chambers assembly is defined as the assembly of first and second chambers, wherein the device further comprises attachment means to attach the chambers assembly to a portion of the aircraft frame or to a portion of the landing gear.

12. The device according to claim 11 , wherein the attachment means comprise at least a girt having an end pad glued to the main envelope outer side.

13. The device according to claim 1 , wherein the second chambers are arranged one after another along the longitudinal direction, with transverse partition walls, and the first chamber is located at a radially outward position.

14. The device according claim 1 , wherein the number of buoyancy chambers is comprised between 3 and 6.

15. The device according to claim 1 , further comprising a pop out protective cover in a packed configuration.

16. The device according to claim 1 , further comprising purge passages at each second chamber to deflate the second chambers after test, the purge passages remaining closed in a normal use configuration.

17. The device according to claim 1 , wherein there is defined a packing density index PDI defined by gas volume obtained at an inflated state under normal conditions divided by an occupied volume in a packed state, wherein the PDI is at least 25.

18. The device of claim 17 , wherein the normal conditions comprise about 1 atm of external pressure and a temperature of about 20° C.

19. The device of claim 17 , wherein the PDI is about 40.

20. The device of claim 17 , wherein the PDI is about 50.