Flying from the Mid-Atlantic to the PNW, California, and back again

[waynemcc999]

It would seem the performance of the oxygen concentrator, especially with the dual cannula, rapidly drops off above 10k feet (or perhaps a bit higher, since it's density altitude that matters here). I suspect the DA at 12.5 was likely 14k or more, so perhaps we were slightly above the limit for the dual cannula.

It's my understanding that the lungs (specifically the alveoli) are temperature-compensating (lots of 98.6 degF blood flow)... and therefore their efficiency relates not to Density Altitude, but to simple Pressure Altitude... so 12,500' MSL would be ~12,500'.

[mhoran]

It's my understanding that the lungs (specifically the alveoli) are temperature-compensating (lots of 98.6 degF blood flow)... and therefore their efficiency relates not to Density Altitude, but to simple Pressure Altitude... so 12,500' MSL would be ~12,500'.

I was thinking DA might affect the oxygen concentrator. But perhaps that's not the case.

[dant]

88%! That's scary to me. I was just doing some tests with my O2D2 the other day tracking my saturation at different altitudes.
Between 5-10k with relaxed (i.e. unconscious) breathing I was dropping to 92 with no O2 - I had the O2D2 set to begin at 10k. If I did some deep breaths I would get up to 95% which is where I feel reasonable. At 92 I definitely felt the effects - I was surprised I was getting them so low as I brought the plane home at 10k with no O2 and no problems with 8ish hours of flying a day. But that was before I got covid. :/

With the O2D2 system I was at 95 with relaxed breathing at 10k, which eeked up to 96-97 as I climbed to 15.5k. I was a little surprised to see it get better as I got higher! BTW: With just me in the plane, 144 TAS at DA of 16,706 at 15.5k indicated at 7.4 gal/hr.

I'm hoping to do a flight from Seattle to Michigan next month if I can get all my ducks in a row to do it. It sounds fun... but at best I can only get 4 days free, so I'd only get 1 full day in Michigan before I turn around and come back.

Regarding your climbing issues out of Spokane, what was your weight with all the XC luggage? It took me 30 minutes to get to 15.5 in the aforementioned flight, but I was ~2250 #s.

[mhoran]

88%! That's scary to me. I was just doing some tests with my O2D2 the other day tracking my saturation at different altitudes.
Between 5-10k with relaxed (i.e. unconscious) breathing I was dropping to 92 with no O2 - I had the O2D2 set to begin at 10k. If I did some deep breaths I would get up to 95% which is where I feel reasonable. At 92 I definitely felt the effects - I was surprised I was getting them so low as I brought the plane home at 10k with no O2 and no problems with 8ish hours of flying a day. But that was before I got covid. :/

I'm definitely suspicious that 88% was accurate, but I do think my oxygen level was partly to blame for the fatigue.

Yesterday on our leg from Tracy, CA to Crescent City, CA we flew at 11k and I used the dual cannula. It seemed to work a bit better this time, my pulse ox was higher than 95% at all times. I also felt that there was definitely more of a bolus of air. Not as much as when I use the single cannula, but it was noticeable.

I reached out to Tom at Inogen Aviator for his thoughts. He said the altitude limits (single and dual cannula) were made with density altitude in mind. So perhaps it was just the anxiety of flying over the Rockies (and the associated elevated heart rate) was a contributing factor.

With just me in the plane, 144 TAS at DA of 16,706 at 15.5k indicated at 7.4 gal/hr.

Wow, that's incredible. Yesterday I had a hard time again getting up to 11k out of Tracy, CA. It was only 90 degrees on the ground in Tracy, so I'm really concerned about the upcoming desert legs. My CHT was climbing rapidly and I also got into the yellow arc on oil temperature. I'm over at Angel City Flyers now having them take a look.

I'm hoping to do a flight from Seattle to Michigan next month if I can get all my ducks in a row to do it. It sounds fun... but at best I can only get 4 days free, so I'd only get 1 full day in Michigan before I turn around and come back.

It's been quite an adventure. I hope the timing works out for you. I highly recommend it.

Regarding your climbing issues out of Spokane, what was your weight with all the XC luggage? It took me 30 minutes to get to 15.5 in the aforementioned flight, but I was ~2250 #s.

Weight is 2570 (w/ full fuel). It took me 24 minutes yesterday to get to 11k feet out of Tracy (90 degrees, nearly sea level). Just about the same out of Great Falls to 12.5k, though Great Falls is at 3680 feet.

I think some of my issue is being used to the ~1000 FPM climb (even fully loaded) at sea level back home. And I haven't been so paranoid about climb performance so I haven't really noticed it dropping off. Now that it really matters, it's making me uneasy. But I've still been able to maintain a climb of 200-300 FPM so long as I raise the nose a bit more than I'm used to and lean out in the climb. Just with a bit of difficulty, given the CHT and oil temperature issues. Hopefully that all gets sorted out today.

[mhoran]

Just got my plane back from Angel City Flyers. Very impressed with their service and facilities. Initially they were unable to reproduce the high CHTs and asked if I'd like them to continue the investigation. However, they did note that the cylinder #1 and #3 intake gaskets were leaking (indicated by fuel stains on the intake risers) and the prop governor gasket was leaking oil. I also asked them to borescope the cylinders, check the mag timing, and per their suggestion change the oil so they could check the oil sump screen. The mag timing was a bit off on the right mag so that was adjusted as well.

CHTs seemed a lot better on my flight from Long Beach to Compton for fuel and then from Compton back to Santa Monica. Of course this was a very short climb and short flight, but the EGTs were also more flat instead of elevated for #1 and #3. I suspect the intake leak likely prevented me from properly running lean of peak, leaving me with elevated CHTs.

The plan is now to start heading back East on Saturday, though it is going to be very hot. So we will see how things go, I may have to split up the return flights into a few more legs if it is too hot.

Flying in LA has been a bit intimidating compared to back East, but I feel I'm getting the hang of it now. The East coast local knowledge isn't written down anywhere -- you just have to figure it out. The LA local knowledge is pretty well spelled out, which is great for visitors, but also a bit much to process on first read. However, once I got the hang of it it's been pretty easy. For example, I had to fly IFR out of Santa Monica to Long Beach the other day and filed a TEC route. We never use those on the East coast (I wish we did!) I had to dig out some dusty knowledge from back in my instrument training days to load the SMO radial noted in the route into my G1000. So it's been a good exercise in refreshing my skills and this trip has certainly made me a better pilot. It's also reminded me of some things I should practice more regularly.

[mhoran]

An amazing trip comes to a close with my plane at SouthTec's hangar at Mid-Carolina Regional Airport in Salisbury, NC. We flew 5176 nautical miles in 21 flights with 52 hours in the cockpit (plus a few more by the time I get my plane home next week!)

On Saturday we began our trip back East. This brought us to Sedona with a balmy 111 degrees at around noon. We decided to spend the night given the heat and potential thunderstorms in Albuquerque, our originally planned overnight. Sedona was absolutely stunning. I was initially intimidated by the challenge of landing in Sedona given the terrain, and the winds were a bit squirrely. But my landing was a non-event, and we got tied down and out of the heat quickly for a lunch break right at the field. We spent the night right on the airport mesa at Sky Ranch Lodge Resort. This was a great choice because it was so incredibly hot and we did not have transportation. We were able to get out of the sun and cool down before venturing out to town for dinner. The hotel offers a free shuttle within 5 miles between 2pm and 9:30pm.

Sunday was a long day which brought us from Sedona to Tuscon via Albuquerque, NM (Double Eagle II airport) and Amarillo, TX. We ate at the diner on the field in Albuquerque, and made a quick stop in Amarillo for fuel. The Amarillo FBO is pretty nice and there is also a diner there, but it closes at 2pm. In Tulsa we landed at Riverside. A great airport with a LOT of flight training. The controller was doing a great job dealing with all the challenges of student pilots. We had a great view of the city as they had us follow the river to runway 19L.

Yesterday (Monday) we ventured on from Tulsa to Nashville, TN. This ended up being one of the most challenging days weather wise, with lots of thunderstorms along the route. However, they mostly behaved as forecast and we made it to Nashville without issue. The smoke from the Canada fires really became an issue between Tulsa and Nashville, so I was happy to be on an instrument flight plan as I could not find the airport from just a few miles out.

Today I started early to beat the storms forecast between Nashville and North Carolina. I was in the air around 8am and got to Mid-Carolina just after noon. Again I was very happy to be on an instrument flight plan as there was significant haze getting in to Mid-Carolina. My pre-flight planning showed a number of thunderstorms along my route of flight but they dissipated as forecast and I had a pretty smooth ride.

The engine is running well post the work performed by Angel City Flyers. I am now able to lean much more aggressively than before and the CHTs are closer to where I expect them to be. The hottest days still resulted in some rather high CHTs but much more controlled than my earlier legs. Unfortunately there still seems to be an oil leak somewhere, so SouthTec will be looking into that. It also seems somebody somewhere carelessly bumped my rudder and it is in need of repair.

All in all this has been an amazing trip and I'm so glad I was able to make it happen. Thanks again to everyone on the forum for your support along the way. It would have been much more daunting to take this adventure on without your help! Here are some photos from the trip: https://photos.app.goo.gl/yzukpjDFTSAEaQHT8.

[dmloftus]

Glad you had a safe and fun journey. Wave to my plane N868US at Southtec, it has been there 3 weeks for what should have been a routine annual. Glenn's shop is moving a lot slower this summer than usual.

[Steve]

Great trip and photos. I've been to Sedona several times for Spring Break, and it is one of our favorite destinations. Winds are pretty much always squirrely there. I saw that you flew over Meteor Crater as well - it looks a lot bigger than when you fly over it in the Flight Levels, doesn't it?

[Colin]

You need a blog. That's an excellent trip and write up.

[mhoran]

Great trip and photos. I've been to Sedona several times for Spring Break, and it is one of our favorite destinations. Winds are pretty much always squirrely there. I saw that you flew over Meteor Crater as well - it looks a lot bigger than when you fly over it in the Flight Levels, doesn't it?

The crater was an incredible surprise! I had no idea we'd be flying over it. It's conveniently located right on the V12 airway, which is what I was flying.

You need a blog. That's an excellent trip and write up.

I have one, but it's tech focused. Perhaps this is technical enough that it will be interesting for my two readers.