Oxygen System

Today I did some research on the oxygen system for our Sling TSI. We plan to fly far and high, but probably only with two occupants. The plane is rated to 18,00 feet, but some have taken it to 30,000 feet. That's exciting, but we need to make sure our plane is equipped with the oxygen system appropriate for those altitudes.

For reference, here are the oxygen requirements at various flight levels:

• 12,500 feet - the crew must use supplemental O2 after 30 cumulative minutes 
• 14,000 feet - pilots are required to use supplemental O2
• 15,000 feet - each occupant must be provided supplemental O2
• 18,000 feet - crew must use an oxygen mask (cannula is no longer sufficient)

As part of our panel we are installing an Aithre Shield 3.0, which monitors CO levels in the cabin, as well as O2 tank pressure and blood oxygen levels via bluetooth connected sensors. The complete oxygen system will require the following components:

• Aithre Shield 3.0 - permanently installed behind the panel
• Aithre Illyrian - smart blood oxygen meter
• Aithre Connect App - monitor tank and blood oxygen levels
• Oxygen Bottle - on the back seat
• Regulator - two outlets
• Oxygen Bottle Harnas
• Finger Pulse Oximeter
• For each occupant:
• O2 flow meter or O2 conserver - controls the flow of oxygen
• Aithre Altus Meso - portable oxygen tank pressure monitor
• Cannulas - for flights between 12,500 to 18,000 feet
• Oxygen Mask with Mic - for flights 18,000 feet or higher

Note that when you are wearing an oxygen mask (above 18,000 feet), you can't speak into your headphone mic. Instead you need a special mask with an integrated microphone. We are planning to install Lemo connectors for the front seat headphones, but now I realize that we will still need the traditional jacks in addition to the Lemos to connect the mask mic.

The range of the Sling is about 850nm or 6hrs of flight time. So we need to size the oxygen supply to cover a minimum of 12 man hours. Instead of a O2 flow meter (constant flow of oxygen), you can also use an O2 conserver, which regulates the flow of oxygen based on demand (when you breathe in). That will stretch the O2 supply on longer duration flights.

We will need USB power in the back, to plug in the Altus Meso. The plane is going to have a USB port in the center console, so that should be sufficient. 

Weight-wise I expect it will add about 10lbs, mostly the full O2 bottle. But when you go on a short trip, or when you are weight constraint, you can at least leave the system at home.

It feels like quite a complex setup, it will look like an interesting science project!