The typical cabin altitude of a jet in cruise is 8000', not 5000'.
How would this device handle atypical aircraft? (e.g. 787, with a cabin altitude of 6000')
Having
all electronic devices switched off for takeoff and landing kind of limits the design/creation of a product designed to continuously monitor the environment and automatically switch off another electronic device.
Having a device to switch off a mobile phone in a Porsche travelling at 155mph down an autobahn wouldn't be a bad thing, either
Rgds.
NSEU