Oxygen

Even minor hypoxia impairs night vision and slows reaction time, so it’s important to have some basic knowledge of oxygen systems. For our discussion, we will limit ourselves to oxygen systems more commonly seen in general aviation. At this stage, there is no need to go into detail regarding oxygen systems typically found on commercial aircraft.

Nasal Cannulas

A cannula is an ergonomic piece of plastic tubing that runs under the nose to administer oxygen to the user. Cannulas are typically more comfortable than masks, but may not provide an adequate flow of oxygen as reliably as masks when operating at higher altitudes. Many cannulas have a flow meter in the oxygen supply line. If equipped, a periodic check of the green flow detector should be a part of the pilot’s regular scan.

Oral-Nasal Rebreather

This type is the most common and least expensive. It is also the simplest in operation; it has an external plastic bag that inflates every time you exhale. The purpose of the bag is to store exhaled air, so it may be mixed with 100% oxygen from the system. These masks supply adequate oxygen to keep the user physiologically safe up to 25,000 feet.

The PRICE Check

Prior to every flight, the pilot should perform the “PRICE” check on the oxygen equipment. The acronym PRICE is a mnemonic that helps pilots inspect oxygen equipment.

• PRESSURE – Ensure that there is enough oxygen pressure and quantity tocomplete the flight.
• REGULATOR – Inspect the oxygen regulator for proper function. If you are using a continuous-flow system, make sure the outlet assembly and plug-in coupling are compatible.
• INDICATOR – Most oxygen delivery systems indicate oxygen flow by use of flow indicators. Flow indicators may be located on the regulator or within the oxygen delivery tube. Don the mask and check the flow indicator to assure a steady flow of oxygen.
• CONNECTIONS – Ensure that all connections are secured. This includes oxygen lines, plug-in coupling, and the mask.
• EMERGENCY – Have oxygen equipment in the aircraft ready to use for those emergencies that call for oxygen (hypoxia, decompression sickness, smoke and fumes, and rapid decompressions.) This step should include briefing passengers on the location of oxygen and its proper use.