A device performs oxygen flight planning calculations for estimating
oxygen usage. The device includes a storage device, an input device for
inputting a known flight parameter value into the storage device, and an
output device for outputting the known flight parameter value input by
the input device. A logic device is configured to control the storage
device, the input device, the output device and provide to the output
device a further flight parameter. A value of the further flight
parameter is calculable by the logic device from the known flight
parameter value previously input into the storage device. Upon the
further flight parameter being selected by use of the input device, the
logic device calculates the value of the further flight parameter and
provides the value of the further flight parameter to the output device.