It’s the day before Christmas Eve and I got the assignment to move a Matrix from Texas to Philadelphia, PA. My non-refundable airline ticket home from Philadelphia is already purchased, scheduled to depart at 8:20am on Christmas Eve. So I’m super-interested in getting to Philly as quickly as possible to ensure no SNAFU’s preclude me from making it “Home for Christmas”. The new owner of the Matrix and I went through the normal rigors of purchasing and picking up a new-to-you airplane (thorough pre-flight, logbook recon, moving of money, etc.) and then departed in the late afternoon, around 3pm.
The weather was perfectly clear for most of the flight. However, huge winds were forecast aloft, and fortunately, they were from the Southeast. The flight was going to take FAR less time if I could fly up into the flight levels. But…I’m in a Matrix! Although a fabulous airplane with unparalleled comforts/avionics, the Matrix is an unpressurized vessel. If I had any hopes of enjoying the 100+knot tailwinds at FL230, I had to use the supplied O2. I’ve made flights back and forth from Texas to the Northeast US hundreds of times, but almost always in a pressurized airplane. This flight provided me the opportunity to contrast, highlight, and underscore the differences between having pressurization and not. For those interested in venturing into the PA-46 world, hopefully this will provide some helpful information to hasten your upgrade.
System description: The Matrix has a supplied O2 delivery system that works really well. A shut-off valve is placed on the panel with easy access and system information (PSI available) is provided accurately through the G-1000 presentation. Outlets are mounted on the ceiling within easy reach of all occupants.
Tubes are plugged into the outlets and O2 flows to the cannulas, which are placed just under the nose. A flow restrictor allows the user to adjust the flow to the desired level of flow.
Required equipment…the Pulse-Oximeter: If you fly a Matrix, you MUST buy a pulse-oximeter! I think it is absolutely required in a Matrix because it is the only way to properly manage your body’s response to lessened atmospheric pressure. The flow restrictor used to control the flow of O2 to the cannula is a complete joke as far as accuracy is concerned. It’s operation is simple…a small ball floats in the tube proportionately with the rate at which the O2 flows. Small indices are printed on the side of the tube showing approximate recommended flows for particular altitudes. If you are using this as your sole O2 management, then you are rolling the dice. There is simply no way to properly calibrate the needs of your body with the amount of O2 supplied without a pulse-oximeter. The result is that you either over-use the O2 (turn it up too high) and deplete your supply too quickly (on a long flight, for example) or you have the rate set too low for your use and become hypoxic.
Using the Pulse-Oximeter: The Pulse-Oximeter is placed on your finger and it has a display that relates the O2 saturation in the body and also your pulse rate. As you go up in altitude, the pressure decreases. The decrease in pressure results in less O2 transitioning from the air to the blood (in the lungs) and less O2 transitioning from the blood to the cell (within the body). The proper functioning of the cells in the body is in direct correlation to the amount of O2 present, and the cells within the body that are most oxygen-needy are the eyes and the brain. So, when the O2 saturation drops (as illustrated on the Pulse-Oximeter), your ability to properly see and think diminish first, and the rest of the body follows in suit. My body usually has a 99% saturation near sea level. As the saturation level drops to 90%, I start to see signs of impairment (reduced night vision, increased rate of breathing, etc.). At 80%, I’m unquestionably affected and have impaired function. At 70%, I’m feeling horrible and entering into the “danger-levels”. At 60%, I’m at risk of passing out (and maybe not recovering). My goal while flying is to keep my O2 saturation above 90% at all times. There is simply on way to know your O2 saturation without a Pulse-Oximeter, so don’t cheap-out on this decision if you fly an unpressurized, turbo-charged airplane regularly.
Pressurization or cannulas: Since the Matrix is not pressurized, the only way to get more O2 into the bloodstream is to increase the percentage of O2 present in the lungs in hopes that more will make the transition from the air to the blood. The best way to provide this flow of O2 is through an oxygen mask. But, the oxygen mask causes all sorts of issues with cockpit communications (no microphone) and is a real burden otherwise. The best way to present more O2 to the body is through a cannula, as this leaves the mouth available for microphones, talking, and drinking/eating.
Wearing the cannula: The cannula is draped over the ears from behind and then placed into the nostrils. Although it doesn’t sound too obtrusive, it really can be. Here’s some problems encountered:
Keeping it in place: When the head is turned, the tubes can bind against the body or aircraft interior and they tug on the nostrils. To remedy this, I placed the tubes under the headset seal around my ear, but this means that I have a less-than-perfect seal for my noise canceling headset. The tube would invariably get pulled at some point in the flight. If you wanted to change seats, the whole apparatus would have to be moved.
Cold in the nostrils: The O2 is rather cold when it comes out of the cannula. This is not excruciating, but it does mean that your nose will “run” a bit, similarly to your having a mild cold on a winters day. You’ll feel the snot running down your nose and rub it, but find a cannula in the way of your efforts to dry your nose. You’ll want to remove the cannula, but the 100kt tailwind reminds you that the discomfort is bearable as it is required to remain up high where all the benefits rare found.
Red spot in the nose: The cannula is made of plastic and the ever-present moisture in the nose area combined with the minor movement of the head means that the cannula moves slightly, just enough to cause a red spot to develop just inside the nose. Again, it is not overbearing, but constantly present, and equally uncomfortable.
Another cord dangling: You already have a headset cord to deal with, and now there’s another cord (tube) that comes from a different part of the airplane. Although a minor nuisance, a pebble in the shoe is also minor until dealt with repetitively. The one extra cord really does add to the discomfort of the flight.
Breathing through the nostrils: If you wear a cannula, you must breathe through the nose. This sounds fairly easy, but you’d be surprised how you must cognitively think about doing so, especially if talking a lot. If you spend anytime breathing with your mouth, you will breathe “normal air”, and you will see a decrease (through your pulse-oximeter) in your O2 saturation.
Monitoring the O2 level: The O2 onboard the Matrix is finite for a given flight, meaning you’ve only got so much available, and then there’s no more. The more that is used, either through excessive flow through improper use, or due to excessive use because there are lots of people onboard, the faster the O2 levels drop. On the flight to Philly, I was passionate about ensuring O2 was available because I’ve had 100+ knot tailwinds! I decided to make a stop along the way back, but the FBO used did not have O2 available for purchase. So, the precious O2 onboard meant the difference between flying at 308 knots overt he ground at FL230 (208KTAS + 100 Knot tailwind = 308 knot ground speed), or flying at 200 knots groundspeed (185KTAS + 15 knot tailwind = 200 knot ground speed). For a guy trying to “Get home for Christmas”, 108 knots of free speed is fabulous! Had I over-used the O2 (by not having a pulse-oximeter), I’d have flown the last few hours of the trip down low (in the bumps) cursing the fact that I didn’t have O2 available. For a Matrix pilot, O2 management is critical.
So, where am I going with this discussion? The point is that the pressurized Malibu/Mirage is twice the piston airplane when compared to the Matrix, simply because of pressurization! The PA-46 was made with pressurization in mind, and it is a fabulous system! With a pressurized vessel, there’s no tubes, cannulas, pulse-oximeters, limited O2 supply, or need to manage those related systems. Yes, there is pressurization to manage, but the pressurization system in the PA-46 is nearly bullet-proof.
There’s lots to love with the Matrix. The interior is the best on the market, the G1000 is the premier avionics suite available on the market, and the PA-46 airframe is a delight to fly. But, and this is a HUGE “but”…pressurization is soooo nice. Once a Matrix owner has tasted pressurized flying, the Matrix will go up for sale. Pressurization is just that good.
Any questions about this? Give us a call at Casey Aviation. We love talking aviation!