Today’s modern corporate jets fly at altitudes that place them in the earths stratosphere. The highest flying corporate jets can fly as high as 51,000 ft. Commercial airliners normally fly between 30,000 and 40,000 ft. The Cessna Citation Encore is certified for flights up to Flight 45,000 ft. At these altitudes the atmosphere is extremely thin and temperatures may be as low as -60 C. If the aircraft cabin were to suddenly depressurize at 45,000 ft a pilot would only have 9-15 seconds of useful conciseness to get his oxygen mask on and sealed. I say sealed because at these altitudes even though the mask provides 100% oxygen, there isn’t sufficient atmospheric pressure to move the oxygen through the membranes of the lungs. A pressure demand mask such as the EROS has inflatable straps that tightly constrict around the head and when you take a breath it forces oxygen under pressure into the lungs. The mask is deployed by squeezing two red triggers at the base of the mask. This inflates and extends the straps on the mask allowing the mask and straps to be placed over the head with one hand. The triggers are then released and the oxygen is released from the straps and the straps constrict around the head, pulling the mask tightly over the mouth and nose. Once the mask is secured in place every time the pilot takes a breath oxygen under pressure is forced into his lungs. a small microphone is embedded in the mask so that the pilot can still communicate over the radio or intercom. This video starts with a demonstration and explanation of the EROS quick donning pressure demand oxygen mask. Pilot oxygen mask are considered quick donning if they can be donned and secured with one hand. It ends with a landing at the St. Louis Downtown Cahokia Airport (KCPS). Just before landing you can hear a “glideslope” audio warning. This is because the main runway with the ILS is closed but the frequency for the ILS is tuned in.