For Airbus, it seems there is no such thing as empty space, with the passenger plane manufacturer designing a mezzanine level that would stack passengers above others' heads.
Telegraph Travel reports the designs show how seats on a second level would allow space for reclining chairs with stair or a ladder leading to the upper seats.
![Passengers would use stairs or a ladder to get to the upper seats. Photo / Airbus, European Patent Office](https://www.nzherald.co.nz/resizer/v2/ASVNITPX4FVC2PC5EJ73OWS2EY.jpg?auth=1e9ff8da82308e544f2a5ac1f14e3703888d8af927f2b2d0b571861463cb00af&width=16&height=10&quality=70&smart=true)
The patent, which was filed to the European Patent Office, states it was important from an economic point of view to make optimum use of the space available.
![The patent said it was important from an economic point of view to make optimum use of the space available. Photo / Airbus, European Patent Office](https://www.nzherald.co.nz/resizer/v2/DOPVP6YGIFCWNFS2CD2BBBQYEA.jpg?auth=eb4321b5ed58dac0b7eb85ef8e44594c145ba25bdd5f2ae7b7feb93281b6952d&width=16&height=10&quality=70&smart=true)