exM20K

Close, but the lower compression cylinders on the TN are inherently less efficient. Book speed at 16,000: -dan

I agree with most of the above: It's more than WX minimums. There are two approaches I like which reside at opposite ends of the flippancy scale. Ask yourself: "How would the accident report read?" ("what a moron" = no-go) use a Flight Risk Assessment Tool, which covers things a new (or old) pilot may not have contemplated. Example here. and, of course IMSAFE and PAVE. -dan

It could also be a single cylinder or one bank of cylinders and not the wastegate or controller. The simple version of an induction leak test in a turbocharged engine is to climb to an altitude of, say, 10,000. Run it hard. Record data, maybe a gami lean sweep. Then run it at ambient MAP, using a 1" / 1000' of altitude lapse rate as "close enough." Eg: if you're at SL and 30.00" altimeter, run 20" MAP and record data, maybe a GAMI lean sweep. If a single-cylinder or even/odd cylinder anomaly disappears in the low-power test, you have a single-cylinder or single-bank issue. NB: the issue could also be the upper deck pressure line(s) to the injector(s). Or the upper deck MAP line to the fuel pump, which isn't supposed to leak fuel back via a faulty aneroid. Ask me how I know... -dan

So if this is not a new problem, have a look at how the MAP drop correlates with oil temperature. It is not unheard of to see warmer, less viscous oil exert less force on the wastegate controller. Considering it holds MAP above 10,000, then maybe not an induction leak after all. 2” is a lot to lose, though. -dan

Agree. I re-trim to the middle after clearing the runway and set takeoff trim by holding it for a count of “Four.” I was advised to actuate the rudder trim only when rolling to reduce the loads on the linkages. This seems to help with the overshoot. -dan

I disagree with my friend @donkaye here. I did the conversion and find it very worthwhile for my needs. The excess power is all about getting off the runway and climb performance. Since I operate half the time from a short, 2500ish foot runway, runway performance matters to me. Since my 90% trip is -740 NM, the ability to jump up to 16-17,000 at a much better rate saves significant time and offers the benefit of well out climbing the dead-stick sing rate. Of course this is not meaningful coming off a short strip with a full bag of gas, but otherwise it is. At MGTOW, the 310 will sustain 1200-1500 FPM at 130 or 120 KIAS. That is 2-300FPM better than book. Excess power means better ability to climb in icing conditions, another safety plus. AC+TKS is unusual. Is that Fizan’s old plane? There should be no excessive vibration. Your student should start with a dynamic balancing of the prop and dig deeper. This is one of the smoothest piston engines I’ve flown. If an unconverted plane has the Type-S prop, the SCT costs something like 1% of hull value. To me, that’s a no-brainer. -dan

That's a pretty long trip. The Acclaim will do that reliably most of the time non-stop. It will out-climb the Bravo and is maybe 10% faster, but the biggest advantages of the Acclaim are its ability to run LOP and a superior climb rate (310HP). I'm not sure a Bravo has the legs to do that trip reliably non-stop. Perhaps Bravo owners will chime in on the range. My 90% trip is approximately 740 NM, burning anywhere between 62 - 80 gallons. Only when we had the dog and couldn't climb to 16-17,000 did we ever have to stop for fuel. The Acclaim is more expensive to buy and maintain. Plan for top overhaul and turbo's at 1000 hours ($6500x2 and ~$25-30,000 for the top) Bravo's have the reputation of making TBO and beyond more reliably. -dan

Cav Aero is the sole source for kits, STC no-hazard or FIKI. FIKI requires dual alternators and a heated stall warning, which is my single least favorite piece of equipment from the single worst vendor I've ever dealt with in my business or personal life. Lincoln Park Aviation would be closest to you for the installation. Good peeps there. -dan

https://www.cav-systems.com/retrofit/mooney-m20-fiki/

As noted above, the 262 was an STC to hang a 252 motor (TSIO360MB) in place of the 231's original (TSIO360GB/LB). It is ineligible for FIKI because it has a 14V electrical system. The 252 is eligible for FIKI, as it has a 28V system. The 252 is upgradable to the Encore configuration, which boots useful load significantly. Useful load is the hole in the 252's game. -dan

Yes,but… The challenges of creating a “modern” aero engine are significant. Deltahawk, for example. Diamond, Thielert, and Austro have had commercial success converting automotive diesels for aero use, but the problems have been, and remain, ever-present. The 1.7 Thielert first generation engines had issues with snapped piston cooling nozzles and cracked heads. The 2.0 Thielert (Continental) were better but had some fuel system issues. The Austro engines started strong but now are operating under a 50 hour borescope mandatory service bulletin to look for cracked pistons with only a promise of a fix in the near future. SMA flopped for reasons I don’t know. Turbines don’t scale down to a 200HP size well. I enjoyed a Wankel in an early 80’s Rx7 but don’t think I’d want to fly behind one. So, tackle all these challenges for a market size as tiny as GA? Meanwhile, what we have in the low-RPM air-cooled spark-ignition aero engines, work pretty well. Yes, continentals need cylinders every 1000 hours, and yes, Lycoming has had materials and manufacturing defects, but these engines work in the existing fleet of airframes. Redbird fit some 172’s with SMA or Continental diesels, and Piper put Continental diesels in some archers. Mr. Market rejected both. If a new suite of engines can’t power our fleet, then vigorously defending 100LL until a viable substitute fuel is found is the only way I see to preserve our investments and freedom of flight. -dan

Vne is a huge buffer over flutter speed. the flutter margin at 2000’ at Vne is way bigger than the margin at FL250. Is Vne solely a flutter margin? I recall Mooney factory test pilots diving until flutter starts as part of certification, of course. Presumably the TAS that induced flutter is then applied to the IAS at service ceiling plus buffer to set Vno. At 2000’ standard day, 190KIAS is about 195 KTAS At FL250, standard day, 190 KIAS is about 290KTAS. kinda a little less margin. Thinking flutter margin is a constant function of indicated airspeed is common. And wrong. -dan

Flutter is a function of TAS, not IAS.

It is astonishing that it didn't come apart and even more astonishing that it didn't deform enough to jam the doors. -dan

A turbine conversion will be airspeed limited to the top of the green, which is pretty close to where the acclaim cruises at/below 10,000. while excess power = better climb, the rudder trim is almost full right as is in a full power acclaim climb, so it is not obvious that the airframe and rudder would take to substantially more power. this project might be fun to do if that is your thing, there are better options available now (LX7, Jetprop, Meridian, Silver Eagle, Bonanza’s) all of which have known pro’s and con’s and a somewhat active secondary market in which to buy or sell. -dan