iphone barometric sensor B747 A380 vs B787

[Quickstatus]

wondering if anyone with the newer smartphones have measured the in cabin altitude at cruise and compared it with the various aircrafts in operation especially the 787

the newer smartphones has an altimeter which operates off barometric pressure.

 

[jb747]

You will need to ensure that you are comparing apples with apples. The cruise altitude will have to be identical.

The cabin is not pressurised to a set altitude; the system targets a differential pressure. That means that the cabin altitude will change with cruise altitude changes.

 

[Quickstatus]

You will need to ensure that you are comparing apples with apples. The cruise altitude will have to be identical. A greater diff will give a lower cabin altitude.

The cabin is not pressurised to a set altitude; the system targets a differential pressure. That means that the cabin altitude will change with cruise altitude changes.

Yes thanks JB747,

It was an interesting exercise on approach into SIN. The compass app also has a tilt function. I had set it down on the seat console and it showed a +2deg tilt on approach which I think is normal. Im not sure if the tit function is accurate as its stationary in a moving aircraft.

Would the cabin pressure differ that much between FL360 and FL400?

 

[medhead]

I wonder if there is an app to log the pressure reading?

 

[Quickstatus]

I wonder if there is an app to log the pressure reading?

There are 3rd party apps that may but Im not sure with what resolution

https://itunes.apple.com/au/app/barometer-altimeter-for-iphone/id923043780?mt=8

 

[jb747]

Yes thanks JB747,

Would the cabin pressure differ that much between FL360 and FL400?

The differential would probably be the same. You hit the max at about FL280 (QF30 was already at it). The resultant cabin altitude might differ by about 500 feet.

i have a couple of pictures of the pressurisation display, in flight. It doesn't show the actual altitude, but I'd place them at about FL 330 and FL400. Differential is 8.7 psi in both, with cabin alt of 5,800 and 6,800.