CoffeeCan

Thanks a bunch, Paul.

Guys, I'm very appreciative of all the info y'all are putting out, but I'm still pretty damn confused. Here's my deal. I fly a 1986 M20K with aftermarket intercooler and Merlyn wastegate and GAMIjectors. I also run a JPI 730 engine monitor. My engine has only about 320 hours since overhaul and it runs very consistently across all 6 cylinders according to my observations of my JPI. CHT's are typically within 20-25 dF at cruise, EGT's are also in about the same variability range. I started flying my aircraft using the basic settings my initial Mooney CFI (David McGee at All American) recommended: 30" M.P. 2500 RPM, and FF of about 12-13 GPH. Over the first 6 months of flying it I searched high and low for more precise engine power settings for given altitudes, eventually drew up a chart based on the M252 performance tables... which meant I was running about 40-50 dF ROP in cruise, which is where lots of folks say the TSIO-360-LB is happiest. Which is OK, except when I wanted to fly a long ways and fuel costs/range became more of a factor... so over the past while I've been playing with LOP ops. Now, the MAPAlog article at Mooneypilots.com says this: "Here's what I tell MAPA members who have an intercooler installed on their 231 - find aT M20K 252 power chart and use it for your engine. Takeoff and climb your intercooled 231 at 36" manifold pressure, 2700 RPM and 1400 degrees TIT. Cruise that same airplane at the power setting we designed the 252 to be cruised at, which is 28" manifold pressure, 2500 RPM, Peak TIT plus 50 degrees rich. Use these settings and your intercooled 231 will be a happy camper and a good performer." ... but most of what I have been reading and watching on YouTube tells me that running LOP has a lot of engine longevity benefits in addition to the fuel economy benefits. So I've been trying to apply a lot of what I've been reading to my own flights, and here's what I've figured out so far. I ain't an engineer, and my ego ain't involved here... I just want to fly my bird as sensibly and efficiently as I can to the next overhaul, hopefully after another 1800 hours. So if y'all have some good advice that I can understand, I'd appreciate it. 1. The POH and the GAMI AFM Supplement both say I should use TIT for leaning procedures, not CHT, not EGT... so that's what I've been using. Maximum sustained operating temp is 1650, but I've rarely reached that, let alone exceeded it. I'm open to using CHT or EGT, though, if that's what seasoned pilots recommend doing... but tell me why, please, as I'm loath to disregard both the POH and the GAMI AFM 2. I've found my airplane likes thin air. I get better cruise speed and economy if I'm up in the teens, so if I'm flying farther than a hundred dollar hamburger run, and the winds aren't really unfavorable, I climb up into the 12,000' - 17,000' range for better KTAS and fuel flow. Running ROP, fuel flows at 75% (estimated) power are in the 11.5-13.5 GPH range. At 65% (estimated) power, running 30 degrees lean of peak TIT, I'm burning 8.8-9.5 GPH. Power drops somewhat, but a loss of 6-8 KTAS is more than made up for by the increased range. F'rinstance, if I fly at 75% power and 40 dF ROP, I have to stop in Arkansas to take on fuel on my way to Wisconsin to see the grandkids. If I run at 65% power and LOP, I can fly from Milwaukee to south Texas without a fuel stop and with a healthy fuel reserve on landing. (Note: FF's are read from my panel FF meter, my JPI does not have a FF readout.) (Also note: I say "estimated" power, as I'm using M252 power settings data due to the installation of aftermarket intercooler and wastegate.) 3. I've been reluctant to run LOP at any power settings above 65%, based on opinions I've read here and there... but now I'm wondering if this is nonsense, or prudence? I'd appreciate some input on this. 4. I have not explored downloading my JPI data into the app y'all seem to all know about... can someone enlighten me?

Hmm. Well, both times I flew here previously they put me in the Bravo all the way to PWK then handed me over to tower, fwiw. This time they had me fly under the Bravo, which was cool, as I didn’t get vectored all over the sky, just flew direct to MDW. My experience at DFW Class B has been similar to yours at NJ, they route you in there with the big boys all the time, but are very professional about it.

Guys, I appreciate all the input. Wish Meigs was still there, but alas... Anyways, we opted to fly in to MDW, picked up VFR FF out of MKE and had a short but scenic flight down over Chicago, landed Rwy 31Center and a short taxi to Atlantic. Regional Approach ATC wasn’t as caustic as usual, which was nice, and they were routing a lot of commercial traffic in and out of ORD. We stayed below the Bravo the whole way in per ATC direction, and were routed direct accordingly instead of being vectored all over the sky. Gas prices suck here, but it is what it is. We caught a nice Uber ride to downtown. All in all, a very pleasant experience.

Fellas, I appreciate all the handy advice and encouragement. VFR FF to MDW was easy peasy, although Regional Approach was cranky (as expected for the Bravo). MDW ATC was cheerful and helpful, and the view of downtown Chicago coming in was spectacular! Two thumbs up!

Brian, I use flight following on every cross country, and anytime I’m near a Class Charlie or Bravo. Just makes sense. I somehow didn’t yet see Martin Pauley’s videos of Midway. The guy does great aviation videos.

I just realized this. Not sure how to delete the duplicate.

I fly into the DFW Class B quite often, and I’ve learned there is a big difference between airports... cranky ATC is the rule at Addison, for instance, and Harrison’s FBO at Arlington is great, and the tower guys are cool. So I wonder which airport small aircraft pilots prefer in the Chicago Bravo? Ive flown into Executive (once) and it was smooth, but it’s a longer drive from downtown than Midway. However, SouthWorst Airlines flies into Midway, so air traffic will be heavier. I have comfort with Class C airports ATC, so that’s not an issue, but I’ll be flying VFR, so that might not be a good fit at Midway? So, any personal experience or observations?

Silly question, perhaps... I fly into the DFW Class B quite often, and I’ve learned there is a big difference between airports... cranky ATC is the rule at Addison, for instance, and Harrison’s FBO at Arlington is great, and the tower guys are cool. So I wonder which airport small aircraft pilots prefer in the Chicago Bravo? Ive flown into Executive (once) and it was smooth, but it’s a longer drive from downtown than Midway. However, SouthWorst Airlines flies into Midway, so air traffic will be heavier. I have comfort with Class C airports ATC, so that’s not an issue, but I’ll be flying VFR, so that might not be a good fit at Midway? So, any personal experience or observations?

Agreed. I am 11 months into my 231 ownership adventure. To say that I have been pleased with my decision to buy a turbo Mooney would be a gross understatement. When I was shopping for my Mooney, I looked hard at a couple of 252's, but couldn't justify the price differential. In the end I bought a well-maintained 231 with recently rebuilt engine (with only 85 hrs on it), intercooler, Merlyn, and GAMIjectors, and upgraded panel, for substantially less than the cheapest 252 on the market at that time. As it happens, my hangar-neighbor bought a 252 about the same time as I bought my 231. I have flown his airplane quite a bit (about 25 hous) over the past 6 months while he's been out of the country. Aside from his panel being a bit cleaner and his interior newer, there's not much to choose between the two aircraft. As Warren says, once you learn the idiosyncracies of engine management in the 231 on takeoff and climbout, there's only a little less performance difference in the 252 and an upgraded 231 like mine. Would I buy a 252 if it was priced right? You bet! But an upgraded 231 like mine is a close second choice. As for turbocharged vs normally aspirated aircraft: the advantages are subtle but real, and in my view make a big difference, especially on long XC flights. The best reason for flying higher, in my view, is that there is far less traffic above 8000-9000 MSL, so your flights are safer. I fly regularly past KSAT, KAUS, and near/into the Bravo around KDFW and KHOU. Under 6000 MSL, there are a LOT of aircraft in these environs, and while most of them are talking to ATC a good percentage of them are VFR aircraft squawking 1200 and monitoring Guard only, if they're on the radio at all. Between 6000 and 10,000 MSL you'll find a lot of commercial traffic descending or climbing into/out of the Charlie and Bravo. But above 10,000, you'll be clear of almost all that traffic. Normally aspirated aircraft are almost all below 12,000 MSL, and commercial aircraft are almost all in the FL's... between 12K and 18K you'll find you're almost alone, in smooth air, often with very favorable tailwinds. And maybe my experience at these altitudes is too short, but I've found that headwinds in the teens are less likely to be turbulent than they are below 6-8000', so even if I'm not seeing a bonus in groundspeed, I'm getting a much more comfortable ride and my engine temps and fuel flow are better than they are down low.

This is very true. My wife and I have used our airplanes for business travel (we are both self-employed) and there is no question that this makes the costs of owning and operating an airplane a LOT easier to swallow. But that doesn't mean the airplanes have been an investment. I have suggested to several people that they might consider starting a side business in a field that they enjoy, as a means to helping defray the costs of aviation. It won't work for everyone, but if it works for you the benefits can be very meaningful.

I agree. I bought my first plane while I was still a student pilot. I had been flying airplanes belonging to my local flying club, and the club went bankrupt just as I was getting ready for my PP checkride. Bummer. I decided renting would be a good option until I did the math... and a friend had a 172XP for sale at a decent price so I snapped it up. I flew it 100+ hours/year for 2 years, and in the process determined what my airplane mission would be. Buying a "starter" airplane (for lack of a better term) makes a lot of sense. It doesn't cost that much to get into ownership, and if you are reasonably careful, you can sell for it in a year or two for about what you paid to get into it. By having your OWN airplane to fly whenever you can or want, you will figure out if you truly do fly enough to justify ownership. I know guys who bought their first airplane and realized after 3 or 4 years that they simply aren't active in aviation to the point of justifying the expense. That is a relatively cheap lesson if you buy a Cherokee or 172, but it's tougher to justify if you are spending $150+ thousand dollars. I don't believe anyone should buy an airplane with a definite time-frame in mind. An 8-year investment makes no sense for folks that are just starting out in general aviation.

I have to disagree with the bolded section above. How is buying a more expensive aircraft sooner rather than later going to cost you any more or less? It costs what it costs. And there is no question that flying a Skyhawk or Cherokee for a couple of years is relatively cheap. The costs of flying a trainer (or slightly advanced trainer) are quite a bit lower than those of a M20K, and you can learn a lot of valuable lessons in the Cessna while doing so. Building that flight time and experience in a simple-to-operate and low-cost aircraft can give the owner-pilot the leisure to build time and experience more slowly and thoroughly, which can save you money later when you're dealing with a more complex aircraft. And you won't be throwing money away if you buy a 172 or Cherokee, either. Resale value and demand remains high for older aircraft. For example, I bought my 172XP in 2016 for $45,000, and sold it this past July for $45,000. I put about $8,000 into it in repairs and maintenance, for a total hourly operating cost over that 2-year period of less than $40/hr, not including fuel.

I would mostly agree with this. I bought my 231 this year after I had accumulated 380+ hours TT over a 5 year period, but 240 of those hours were flown in the 22 months prior to the Mooney purchase, and nearly all of them were in a "complex" Cessna 172XP (Continental 6-cyl engine with constant speed prop). Personally, I found having that much time running a FI Continental really helped me with my transition into the 231. And having a good bit of flight experience in differing flight conditions, including some instrument training, gave me experience I was really glad to have as I learned my Mooney. In the 95 hours I've accumulated in my 231 since July, I've learned a LOT about engine management and a LOT about handling the aircraft, and much of that learning would have slipped right past me if I hadn't already learned a LOT in accumulated hours in my Cessna. Depending on whether you have the -GB or -LB engine, and on your engine monitoring system, learning to run your Continental TSIO-360 may be easy or it may be less easy. If you have a JPI monitor with good transducers and GAMIjectors, it will be pretty easy. If you have the original factory engine instruments only, it's gonna be harder. I expect you will be dunned by your insurance company for your low total time and low time in type. This may be significant. Also, you will almost certainly be required to take a minimum number of hours of dual instruction from a certified Mooney CFI. This isn't a bad thing. I spent 16 hours in the cockpit of my 231 with David McGee of All American Aircraft, and it was well worth the time and money to do so.

Where did you order the new seats? They look amazing!

MKTurbo... Actually, pulse oximeters can be pretty iffy. I rely on them daily at work (ER) and they can be fussy and/or really unreliable. Like any small electronic device, individual pulse oximeters can be quirky, incorrectly calibrated, or just "lemons". In the medical setting we use oximeter transducers that connect directly to our wall monitors, which are much more reliable than the compact portable battery-powered devices. Even then, it's not uncommon to have to switch from one hand or digit to another because of quirks in getting good readings. Taped-on transducers work better than the ones that are held on by spring pressure, also. We routinely check our portable pulse oximeters against the wall units, and often have to replace the portable units because of inaccurate readings. A pulse oximeter measures the percentage of hemoglobin molecules in the blood that are saturated by oxygen, which induces a color change; as such, it detects hypoxemia, or low blood oxygen concentration. This isn't the same thing as hypoxia, which denotes low oxygen concentration in the tissues, most immediately in the brain. One can have transient hypoxemia without being clinically (or aeronautically!) hypoxic. Transient hypoxemia is anticipated above certain density altitudes (arbitrarily 12,500, but this is by no means a "safe" altitude), but this will usually not cause clinically significant hypoxia unless the hypoxemia persists for longer than a few minutes. This is why the FAA gives you 30 minutes of leeway between 12,500' and 14,000' MSL. However, there is no clearly "safe" level of hypoxemia and some brain functions are demonstrably impaired at altitudes as low as 6000' MSL, at which point retinal function becomes impaired and night vision degrades measurably. It was in consideration of these factors that I decided to get some good baseline measurements of my SpO2 (oxygen saturation readings) before flying my new-to-me M20K above 14,000' MSL. As jlunseth suggested, the portable pulse-ox I bought may not be giving accurate readings, but it definitely shows trends that suggest caution when using my on-board supplemental oxygen equipment. I had noted in my pre-O's days in my Cessna 172 that I felt a little breathless at 11,000' and above... and my pulse oximeter showed my SpO2 was definitely trending downward above 8000-9000', and O's were required at 12,000'. Interestingly, I get higher readings in my middle finger than my index finger, and in my left hand rather than my right. Higher readings are more likely to be accurate. Also, when I checked my wife's SpO2, she got readings in the 70's... but she wears thick red nail polish. Other factors can confound the pulse-ox, as well: cold hands, thickened fingernails due to onychomycosis, and so forth. As for your hypoxemic flightmate in 2013: jaylw34 commented, people with chronic disease can be perfectly comfortable with quite low SpO2's... but in the 70's, it's highly unlikely he would be able to tolerate this and not have blue lips and hands. Most likely he has an anatomic or other functional impediment to good SpO2 readings.

jlunseth, I too am suspicious that the readings I'm getting from these oximeters are not accurate. I should have refrained from posting any results based on those oximeter readings, so please take them with a grain of salt, but they do illustrate the trend in diminishing SpO2's at relatively low altitudes. I have another oximeter on order at present and will update you when that comes in. And yes, I'm using Oxymizer cannulae, with the MH3 flow meter. Masks at FL180 and above are, of course mandatory. I have a set of masks on order (with MH4 flow meter) to test as well. We likely could have a lively conversation as to the relative values of pulse oximetry readings when compared to actual arterial blood gas numbers...

I appreciate all the replies on this thread. My M20K's oxygen system works fine, but it's good to know that it can fail at the left "door" panel control knob. One more thing to watch out for. As I'm a bit of a physiologist with past experience in mountaineering, I was/am very much aware of the need for O's... not just to meet the FAA regs, but for physiologically significant hypoxia at any altitude. And both the mountaineering literature and the aviation literature are full of stories of failure of regulators, dilution systems, masks, hoses, etc. Based on that knowledge, literally my first purchase for my new-to-me 231 was a couple of pulse oximeters, which I made sure were operable before I did any flights with O's running. My findings have been interesting. Here's what my numbers have shown me: 1) My blood oxygen saturation drops below 90% at indicated altitudes well below 10,000'. Since we consider 93-94% "normal" in a medical setting, levels under 90% are potentially hazardous for pilots. The brain, particularly the visual part of the brain, will not be functioning well if the blood oxygen saturation is in the 80's. This is why the FAA recommends use of O's for pilots at night above 6000'. 2) I don't start feeling "air hunger" until I get up to around 10,000 to 11,000' MSL indicated. By that time, I'm registering sats in the mid-80's. This tells me that my brain's ability to judge whether I'm getting hypoxic isn't very good. Hence the need to have a pulse oximeter in the cockpit and use it. 3) The in-line flow meter my oxygen lines have (nasal cannula only, so far) is calibrated up to 18,000'. How-88%ever, when I'm flying at 17,500' and I have flow meter pegged wide open, my pulse oximeter tells me my SpO2's are only running 85-88%. This tells me that the little ball in the tube isn't necessarily telling the truth. Again, you can't trust your oxygen equipment to say what you think it says... Now, I've ordered a couple of non-rebreather masks with flow meters that go all the way up to 25,000' from Mountain High, but I haven't tested these yet. Stay tuned for that report. 4) If your O's fail you when you're flying at or below 18,000', you will probably be able to tell if you have a sudden failure of your oxygen system and onset of hypoxia in time to make an emergency descent to 12,500 or below in a timely manner. But above FL180, you may pass out from hypoxia before you can take corrective action. As such, it seems highly prudent to me to have the pilot (at least!) wear a pulse oximeter equipped with a warning light/tone at all times when flying in the flight levels. Having an emergency descent profile pre-loaded into your GPS/autopilot for such emergencies seems prudent as well. So that's my dos centavos on this deal.

Thanks, carusoam. We are committed that weekend for a family wedding, so we will have to look at the next one. I sent the link to my wife so she can make her own plans.

Tell me more about Right Seat Ready. My wife is not a pilot, but has voiced and demonstrated real interest in being a strong co-pilot. She is learning the radios already, and wants to be involved in both VFR and IFR approaches and landings. I expect she will advance to PP eventually, but she wants to be a strong right-seater first.

81X, my transition training this past July was similar... I took 15 hours dual from David McGee at All American Aviation, and it was worth every minute and every penny, but we didn't hardly scratch the surface of the avionics. David used to be chief test pilot at the Mooney factory, and it's apparent that what he has forgotten about flying Mooneys isn't worth remembering. Outstanding instructor and a great guy. Most of what we concentrated on was engine management, takeoffs, and LANDINGS. Oh, and did mention engine management? We did a lot of engine management. Landings training included both descent/arrival procedures and visual approaches. We did not even begin to work with IFR. I left after instruction with 35 landings under my belt, and David's assurance that I probably wouldn't kill myself in the plane... but he also strongly suggested I not fly with passengers until I'd done at least 5 more hours in pattern work solo, and that I not fly at night or IFR. Sound advice, that. I didn't take my wife up in the Mooney until I had 25 hours in her and better than 45 landings. Transitioning from a Cessna 172 or Piper Cherokee to a turbo Mooney is like going from a Yugo to a Maserati.

This is my experience with my 231 as well.

Don, I share your opinion of David, and hope to become a good friend with him as well. We're off to a good start, in any case!

jlunseth... Thanks for your detailed reply. And yes, that is the article I was referencing. Your recommendation of about 29-30" MP and 2450-2500 RPM is where my initial CFI advised me to run, if I recall correctly, in my initial training in this aircraft. I do have a JPI already (EDM 830), it just doesn't have the fuel flow and oil temperature transducers installed yet. On the extended trip I took in my 231 last week (2200 NM over 4 days) I was watching EGT's and CHT's on all 6 cylinders, and they seemed to be running very uniformly. CHT's were in the mid-300's IIRC, but I haven't figured out the download process yet. Sounds like learning that and getting the Savvy app running are steps I need to take in the near future. Interestingly, I found 13.3 GPH seemed to be the "sweet spot" for maintaining 75% power and oil temps in the green range on the analog oil temp gauge, with a TIT of just above 1400.