Aircraft modular lavatory system

1. A modular lavatory system for replacing an existing lavatory monument in an aircraft cabin, comprising:

a base lavatory module comprising a fore sidewall, an aft sidewall, and an aisle wall that form a housing enclosing a toilet unit, wherein a first sidewall of the fore sidewall and the aft sidewall includes a widening region positioned above a passenger seat headrest height; and

at least two interchangeable modules configured for mounting against another sidewall of the fore sidewall and the aft sidewall;

wherein a footprint of the base lavatory module is smaller than a footprint of the existing lavatory monument, such that an extra cabin space is created proximate the other sidewall of the base lavatory module, wherein the at least two interchangeable modules are each dimensioned for installation within the extra cabin space.

2. The modular lavatory system of claim 1 , wherein one of the at least two interchangeable modules is an upper stowage module configured to abut an upper portion of the other sidewall of the base lavatory module.

3. The modular lavatory system of claim 2 , wherein the upper stowage module is configured for installation between the other sidewall and a side panel of an overhead storage bin in the aircraft cabin.

4. The modular lavatory system of claim 1 , wherein one of the at least two interchangeable modules is a floor stowage module configured to abut the other sidewall of the base lavatory module.

5. The modular lavatory system of claim 1 , wherein one of the at least two interchangeable modules is an attendant seat module configured to abut the other sidewall of the base lavatory module.

6. The modular lavatory system of claim 1 , wherein one of the at least two interchangeable modules is a flex wall module configured to abut the other sidewall of the base lavatory module.

7. The modular lavatory system of claim 6 , wherein the flex wall module includes at least one of a beverage and a snack kiosk.

8. The modular lavatory system of claim 6 , wherein the flex wall module includes a stowage cabin.

9. The modular lavatory system of claim 1 , further comprising a sidewall filler panel for covering an inner surface of the aircraft cabin beneath the widening region, wherein the inner surface was originally covered by the existing lavatory monument.

10. The modular lavatory system of claim 9 , wherein the sidewall filler panel is integrated into the first sidewall of the base lavatory module.

11. The modular lavatory system of claim 9 , further comprising a second sidewall filler panel for covering an inner surface of the aircraft cabin adjacent to the other sidewall of the base lavatory module.

12. The modular lavatory system of claim 1 , wherein the modular lavatory system is fixable to a structure of the aircraft cabin using at least two upper monument anchors provided for fixing the existing lavatory monument, wherein the base lavatory module is fixable using a first upper monument anchor of the at least two upper monument anchors, and a selected interchangeable module of the at least two interchangeable modules is fixable using a second upper monument anchor of the at least two upper monument anchors.

13. The modular lavatory system of claim 1 , wherein the base lavatory module further comprising a door in the aisle wall of the base lavatory module, the door including a wider upper portion and a narrower lower portion to form a profile conforming to a profile of an aisle attendant seat mounted to the aisle wall proximate the door.

14. A method for replacing a conventional lavatory monument with a modular lavatory system in an aircraft cabin, the method comprising:

positioning a base lavatory module in a region of the aircraft cabin previously used by the conventional lavatory monument, wherein

the conventional lavatory monument utilized a footprint having a width X,

and

positioning the base lavatory module comprises positioning a lower edge of a first side panel of the base lavatory module of the modular lavatory system near a first end of the width X of the footprint, wherein

the base lavatory module has a lower width less than X and an upper width greater than the lower width, wherein the first side panel comprises a widening region disposed above a passenger seat headrest height and extending to an upper edge of the first side panel;

anchoring the base lavatory module to an upper structure of the aircraft cabin using one of the at least two overhead anchors;

positioning an inner side panel of a selected interchangeable module of at least two interchangeable modules proximate the other side panel of the base lavatory module;

and

anchoring the selected interchangeable module to the upper structure of the aircraft cabin using another one of the at least two overhead anchors.

15. The method of claim 14 , further comprising:

relocating a preexisting aisle attendant seat to a location proximate an aisle panel of the base lavatory module such that the preexisting aisle attendant seat does not block a door in the aisle panel of the base lavatory module.

16. The method of claim 15 , wherein a seat pallet of the attendant seat is fixed to structure of the aircraft cabin using a preexisting standard interface attachment provision.

17. The method of claim 14 , wherein positioning the lower edge of the first side panel near the first end of the width X comprising positioning the lower edge of the first side panel such that a sidewall filler panel covers an inner surface of the aircraft cabin beneath the widening region originally covered by the conventional lavatory monument.

18. The method of claim 17 , wherein the sidewall filler panel is integrated into the first side panel.

19. The method of claim 14 , further comprising sealing the selected interchangeable module to the base lavatory module along abutting panels using a releasable seal.

20. The method of claim 14 , further comprising releasably fixing the interchangeable module to the base lavatory module.