Marc_B

@Gatlin Gun I’m up at GXY and I know two guys out at CFO…Mike and Brett both fly J’s. Have Mooney friends over at BJC, LMO, and COS as well.

Mobility and portability. For patients stuck on oxygen it's been amazing to have a portable concentrator that fits on a shoulder strap instead of lugging around a tank. Same for pilot. No need to refill tank. No need to lug around a tank. Plus as @donkaye, MCFI mentioned, you can easily bring it commercially from one plane to the next. It's another tool in the toolbag, and has it's own pros and cons. It doesn't work for everyone, and I'm not giving up my built in oxygen with an O2D2 that I fill once to twice a year (at annual or at my FBO). But it IS legitimate and works well for those who use them.

How well does it work for you in 1 or 2 person set up? It's misleading because you're blindly taking a recommendation that may or may not be applicable to the person using it and painting broad brush strokes. 2 person mode might not work for someone at all. However the machine concentrates oxygen. It's working as intended. But the guideline isn't law and may or may not be applicable. ANY oxygen equipment you you should be end user tested to verify it's working properly and that you find the settings that work for you. Don't blindly follow any manufacturer recommendations "trusting" that they work for you. Maybe they oversold it, or maybe they're way conservative. But DO follow FAA regulations, because that's how we protect our privilege to fly.

I think that the thinking is I’ll try to avoid low IFR or potentially unsuccessful approaches with forecasts and planning, where I can. But once I’m on an approach I’m not going to unnecessarily limit my success if I feel it’s safe and I’m comfortable and legal. i.e. If my personal min is 600ft AGL and forecast were 1000ft it’s a go. Then I get there and ATIS ceilings are 400ft (LPV min 200) then that might not be accurate at the time I’m on approach. Perhaps it’s 100 perhaps it’s 600 where I am. But it the approach is going well, I’m ahead of the plane, my AP is rock solid, no turbulence, things look good…why not fly the approach to land if able?

This is misleading, because oxygen equipment is doing exactly what it was designed to do. But the part you’re missing is the testing. given that we are all different I wouldn’t advocate ANYONE use oxygen equipment without directed self testing. Heck, we’ve had pilots that the O2D2 didn’t work well for as well as systems where it worked very well. there are recommendations, guidelines, and regulations. They aren’t the same. Some pilots need oxygen at 10,000 ft. some may not get a pulse delivery system to work well for them. Some will. what we don’t have is extensive testing of service ceiling if the various units. there’s nuance here. Don’t paint in such broad strokes. follow regulations. But take manufacturer recommendations as a place to be confirmed by end user testing. They might be over or understated.

@MarcJohnson is CFI/CFII in Colorado Springs and might be available to go out with you, fly back and do transition training along the way or back here in Colorado. Also agree with @donkaye, MCFI based in CA for instruction as well as possibly @kortopates. @caractacuspdoom I think you'll probably have several options depending on their availability, but agree that having someone fly back would be a plus as well as more fun!

But if you’re asking how would this fare with a chronically oxygen dependent COPD patient passenger…completely different story and completely different risks. probably ask if they’ve flown commercially and safely and if not, then no go. If so then fly <8000 ft MSL.

1) I think that in general (and for me) a nasal cannula is insufficient above 18000 ft. 2) I can’t say as I haven’t seen any data or personally used it. Can an Inogen be us d with a facemask? How does it compare with me personally? so besides just echoing manufacturer’s recommendations I couldn’t tell you. BUT, I think a solid plan would be to fly with a friend on a XC, one using Inogen and the other on built in oxygen and perform a flight test. Of course knowing that rest, hydration, fitness, etc all can make day to day result differences with same person. However if a concentrator resulted in same or better oxygen saturations up to 18,000 ft I’d say that’s a positive result. Goal for me is > 96%. personally wouldn’t use it in flight levels without better manufacturer guidelines and testing. But zero apprehension of using a pulse demand oxygen concentrator below 14,000 ft.

This is greatly dependent on the altitude that you're flying (ultimate partial pressure) as well as the speed it drops. i.e. 15,000 feet gradual decline to a low reading of 93%, vs 28,000 feet declining down to 69%. Its also a good reason to routinely check your pulse ox anytime you're at altitude on oxygen (i.e. every 10-15 min) and with any question of symptoms or issue. But you're correct in saying that often a SLOW change/decompression is probably more dangerous than a RAPID change as the rapid decompression demands attention. It's also why I like the pulse demand delivery system as there is a more noticeable difference between flow and no flow. The term that helps describe this is Time of Useful Consciousness/Effective Performance Time. FAA Aeromedical Factors Ch 17. AC 61-107B I have 2 pulse oximeters that I fly with. One stays hanging on the prop knob. The other is in my flight bag in the back seat in a location that I can easily grab it. If I'm in the FL's, I set a scheduled timer on the GTN for 10 min to say "check SPO2". Makes it easy to keep honest. Any question or by issue, by default, is an immediate request for descent to troubleshoot. Flight level altitude isn't the time to "sort things out." Yes, there are risks; yes there are mitigation tools and redundancy to make this safer. But flight is a series of choosen risks and mitigation training/techniques. You can't remove them all, and there are many risks that are way more likely to happen.

You'd be surprised. We routinely check pulse ox on everyone from critical ill to standard vitals for a sprain in an otherwise healthy patient. Skin pigmentation, fingernail polish, poor circulation, cold fingers...even healthy people have fingers that might not always read properly. Most problematic I'd think would be use of fake nails/nail polish and vasoconstriction from just being cold in the winter or at altitude. Some people also have hypersensitive vasoconstriction to cold (i.e. Raynaud's) and might not get a great reading at times. This is why I think it's important to establish your baseline for what "seems right" for you and what seems like somethings "off". Most of the decent portable pulse ox's that I've seen have a bar that beats up and down showing wave form. If that's not correlating with your pulse, then it may not be accurate. Some newer units have an OLED screen that actually show wave form. Its a good idea to have a rough idea of where you "trend" at various altitudes as there are lots of variables in each of our "high altitude" physiologies.

That's not what I experience with hospital equipment. I'll routinely see an inaccurate number with a poor pleth, that improves with a better pleth (or vice versa). Sometimes it's poor distal perfusion, hypotension, or cold fingers. But if you don't see a good pleth, you can't trust the number that's displayed. So you'll commonly hear someone say "they were 82% with a good pleth" meaning it was accurate. In terms of the background programming to not show a reading if a wave form isn't sensed...I'm not sure the detail of how the portable units are programmed.

I think what you mean is that "homerolling" your own cascade might be problematic. (i.e. if resistance/length/tube diameters/etc weren't considered you might get differential flow rates) However, I think if you used a cannula cascade that was designed for equal flow then I think it's feasible. If you consider that you're using one oxygen canister with standard built in oxygen, using one canister with a Precise Flight or Mountain High portable oxygen set up.... But you also have to realize the failure points with ANY oxygen system you use. The failure points of each set up has it's own merits...built in, portable, pulse demand vs continuous flow, etc. But for people using supplemental oxygen at 10-15,000 ft MSL...the FAA Time of Useful Consciousness is indefinite. Meaning the FAA won't care what oxygen equipment you use below 15000 ft MSL. You have more likelihood of CO poisoning than significant altitude (hypoxic) hypoxia at these altitudes. Time of Useful Consciousness 15,000 feet — Indefinite 20,000 feet — 10 minutes 22,000 feet — 6 minutes 24,000 feet — 3 minutes 26,000 feet — 2 minutes 28,000 feet — 1 minute 30,000 feet — 30 seconds 35,000 feet — 20 seconds 40,000 feet — 15 seconds

I think the FAR is defining a dispensing unit as the mask or cannula. i.e. I have one oxygen cannister built in, but I have 4 outlets that allow 4 cannulas (one for each occupant).

@Paul Thomas A pulse oximeter estimates the oxygen saturation of blood (SpO2) and pulse rate by shining two different wavelengths of light (red and infrared) through the fingertip and measuring how much light is absorbed/transmitted. Oxygenated and deoxygenated hemoglobin absorb these wavelengths differently, allowing the device to calculate the percentage of hemoglobin that is saturated with oxygen. An important tool for any SpO2 reading is plethysmography tracings or "pleth" or "waveform" which is a measure of volumetric changes associated with pulsatile arterial blood flow. Inconsistent or distorted pleth may result in changes to the computer calculated value resulting in artificially HIGH or LOW SpO2 reading. Therefore, plethysomography ensures reliability of the calculated oxygen saturation. With carboxyhemoglobin (i.e. carbon monoxide poisoning), the abnormally bound hemoglobin has similar absorption spectrum as when O2 is bound...so it can be falsely interpreted by pulse oximeter as "saturated" even though you are actually hypoxic and have a LOW total amount of oxygen in the blood. CO binds to hemoglobin MUCH more strongly than oxygen and so carbon monoxide actually displaces oxygen from your hemoglobin. This is why it concentrates over time and longer duration is a more damaging effect as more and more CO is bound and less and less oxygen is carried in the blood and delivered to tissue. Here's a great medical site going deeper into the details: https://medicine.uiowa.edu/iowaprotocols/pulse-oximetry-basic-principles-and-interpretation

TLDR: pulse demand oxygen concentrators may not have the same "efficiency" as each other and some may have more "horsepower" to continue to maintain adequate oxygen concentration output with lower partial pressure of oxygen at altitude. But I don't think that the "service ceilings" of these devices have been well defined. So I think that you're left more with manufacturer recommendations rather than FAA regulations with these devices. That's not to say they don't work, and have well proven benefits with portability and ease of use.

I think that this topic is difficult without scientific data and clear regulatory data, because the basic goal of supplemental oxygen is to avoid hypoxia and we have a clear way to define this with a pulse oximeter. But not all equipment is the same (pulse demand, continuous, tanks vs concentrators, cannulas vs oxysaver cannula vs mask vs mask with reservior, etc.) Typical recommendations from FAA have been 1LPM flow rate for every 10,000 ft altitude. Typical oxygen concentrators can deliver anywhere from 1.5-20 LPM flow at 87-99% oxygen concentrations (vs 21% FiO2 at sea level ambient air). Most medical devices are tested up to 10,000 feet so you'll often seen this as a "standard". However, the goal of certification of medical device is different than what might be considered for aviation device...i.e. there is no prescription for 2LPM continuous "dosage" for pilots, but rather it is self titrated to avoid hypoxia. Nasal cannulas entrain ambient air in addition to the flow from the cannula, and opening your mouth/speaking also entrains more ambient air, which is why above 18,000 feet you are required to use a mask that covers the mouth and nose. Above 18,000 feet the partial pressure of oxygen is low enough that a standard nasal cannula is no longer effective for most. However, I'm not sure if it has been well studied what the service ceiling of pulse demand portable concentrators are and if you can "override" the drop in oxygen concentration with increased flow rate. I would suspect that this would depend on the units efficiency (i.e. some units likely have lower ability/service ceiling) and I also suspect that at some altitude, the oxygen concentration output drops and cannot be accommodated with flow increase. I'm also not sure if the differential effects of using a face mask vs cannula with a pulse demand oxygen concentrator have been studied. i.e. what flow is required for a face mask vs using a simple cannula? and does the "service ceiling" of the concentrator change with use of a mask vs cannula? I reached out to the FAA CAMI (Civil Aerospace Medical Institute) to see if they've performed any testing with this and if they have a recommendation on who I could speak with. The answer is that there is some regulation on the use of oxygen devices in aviation. But it's clearly not exhaustive with current technology. However the goal being normal oxygen saturation is clear and easily defined with an accurate pulse oximeter. Of course not all pulse oximeters are equal, and not all show a wave form to tell you they are reading accurately. So you CANNOT just assume that you're fine if the number reads over 90%. They can also give false readings with CO poisoning as well.

So I finally bit the bullet and got the warranty servos ordered. Flying back from Florida in April it was porpoising at times up to 1000fpm up and down. Didn’t see any change using PIT, and didn’t see any difference using alternate static source. Seems like issues would wax and wane. But then I got a red Pitch trim error on the PFD and electric trim wouldn’t work. This resolved with cycling the AP circuit breaker. Got a transient flag that went away a couple more times. I talked to my shop about warranty 1 vs all 4. They thought it made more sense to do them all and be done with it. So hopeful should get this taken care of this week and back to a rock solid AP like it had been up until now. For reference, original servos installed Oct 2022 and have about 300 hrs on them.

@67 m20F chump pictures? Did you use the silicone glue or another (i.e. 3M adhesive)? I've got a baggage and cabin door set from GeeBee waiting to be installed.

https://adsbperformance.faa.gov/paprusersguide.pdf

@TGreen I’d still run a performance report off the flight you had issues to see what it shows. Might help in future if issues reoccur.

It's interesting to see how everyone chooses their layers and how different some of us are. I find (not completely intentionally) that I usually have the aeronautical map up as well as either the VFR or IFR low depending on what I'm looking for. Flying in the mountains on a joy ride - VFR. On a XC flying IFR - IFR low. But I don't think I've ever gone with just the aeronautical map except for transiently or if I'm trying to quickly declutter. Of course most of my in flight use of iPad is more "looking around" as I do most of my navigation/traffic/etc with the panel.

Agree...do a FAA performance report and see what that pulls up. According to Garmin, the most common cause of intermittent ADS-b failure is terrain and antenna masking. Check your maintenance manual for troubleshooting information. But if you can't find info, this info may be somewhat applicable...from GTX transponder manual. For the intermittent issue they point to antenna, coax, ground plane. Big question is if you've changed anything recently and where is your antenna? Any chance of damage?

I read threads like these and I think that most of the time the general sentiment is "sucks for the new Mooney owner" but is a pearl of wisdom for the potential "future Mooney owner." We fly amazing, but often much older aircraft that have potential for lots of high cost items to fix. Ounce of prevention beats a pound of cure, unfortunately. Moral of the story is if you don't have the experience and expertise to do your own evaluation, a prebuy should be a given unless you know the person and know the aircraft (or get a smokin deal that makes any issues doable...although some corrosion has the potential to be cost prohibitive). Its also very interesting that in aviation the idea of getting someone to "make things right" after the fact doesn't seem to happen that frequently. These issues, unfortunately need to be caught up front and dealt with or typically turn into "owner issues."

I don’t think I’ve ever quite understood how to answer questions like this as it’s so dependent on conditions. Meaning I might say it “starts” at legal minimums and goes up from there based on conditions and situation surrounding the flight. night, single pilot, convection in the area, fuel status, fatigue, recency/proficiency, familiarity with area, lighting for approach and runway (or lack thereof), autopilot or hand flying, type of terrain/mtns/obstructions, etc. These are all migitating factors that would increase my personal decision height. But under ideal circumstances if you’re proficient and have a capable aircraft it’s absolutely NOT the approach “min” that’s driving my decision making process…rather it’s the idea of flying into an area that has few alternatives in an emergency. So it’s not a “decision height” while on the approach, but rather my comfort (or not) to fly into an area with all the terrain obscured and how much height above terrain I feel is prudent.

I had an iPad Pro 11" 2nd gen that I tried everything and would unpair all equipment, cycle power and re-pair. It would work for a while but got to where it would pair, kick off everything else and say traffic coast on the Aera 760, then fall off and the Aera would work again. I changed to an iPad Air (M3) and no issues with fall out or pairing. I'm not sure if its a bluetooth link that's just going bad or older technology that wasn't working right? But I believe it was the iPad connection all along. Not sure on the back end what the underlying issue is that kicks off other connections and has issues pairing...