Airbus A320 crashed in Southern France

[lapp]

But he is still wrong. Take a look at this Embraer 145 manual, using the standard Eros oxy system.

.. Only normal (N) oxy selection is required for all flight conditions, and it is normally diluted.
.. Above 33,000' the mask auto switches to 100% oxy.
.. (The valves sense the pressure. Note that it says if there is a depressurisation the mask will auto revert to 100%.)
.. There is a backup manual 100% switch, if you require.
.. But constant flow (emergency selection) is only required to prevent the pilot breathing fumes.
.. (That is why it is called 'emergency selection', and not the 'above 35,000' selection'.)

This is what our system says too, if I can find the book...

http://www.smartcockpit.com/docs/OXYGEN_E1.pdf

Again, if you have a reference that says something different, then please provide it.

I have read the references and relates postings and must say that what you say is correct. Notwithstanding, it is my totally personal opinion, that setting "EMER"for mask breathing at FL 380 can't do nothing but help breathing. Would you elaborate on the possible negative consequences of doing that.