231LV

This is a first in over 20 years of flying my 231. I have had my share of really bad landings but today took the cake. Coming in a bit high and fast, I got sloppy and overconfident and instead of popping the speed brakes (which I actually thought about for a moment) I let the plane float...one bounce, two bounce then down but too far down the runway and too fast so instead of executing a go-around, I stomped on the brakes and was told I was smoking the tire for several hundred feet before it blew pulling the plane to the right. I was fortunate that all I appear to have damaged (beside my ego) was the tire. Warning to all out there, don't get overconfident...no matter how long you have been flying and if you believe you need to go around....GO AROUND!

As others have said, there are many variables to consider when setting these engines up. I had my GB overhauled to an LB and had a Merlyn installed at the same time. The original engine came with an intercooler.....so...setting up FF with the intercooler was a bit more complicated than simply referring to a chart since the book had the FF set too low causing CHT's to go over 400 before rotating. Bottom line, my FF ended up at 23 gph at 37 MP. The intercooler requires a reduction in MP to avoid overboosting the engine. Prop RPM is limited to 2700 but I usually see 2650 at 37 MP which is my "max power" setting.

One of the great reasons this forum works so well is follow-ups on previously reported problems. I reported a frustration I was having with my volts on start-up well over a year ago. To recap, I would start up and the volts would hover around 12.3 volts before it would climb to 13.7v. Many opinions were offered from a voltage regulator issue to an alternator. One respondent offered that this was normal and the charging system was designed this way to prevent a voltage spike on start-up. The problem turned out to be a slipping coupler on the alternator. I suspect it had been slipping this whole time and progressively got worse which was verified when my last flight saw voltage sit at 12.0 volts. I now know that after replacing the alternator and using a solid state voltage regulator (either works or it doesn't), the most likely culprit is a slipping coupler. Hope this helps save some time troubleshooting a similar issue.

Thanks to all the responses to this thread. I now have a pretty clear understanding of where things stand. To summarize: 1) Electric speed brakes can be fitted to replace the original vacuum brakes. 2) They are expensive. Vacuum pumps are not. 3) If I elected to spend a lot of money to replace the vacuum with electric speed brakes, I would still have to spend more money to upgrade. my Aspen 1000 to an Aspen 1000 Max before I could completely scrap the vacuum system. 4) Replacing the vacuum speed brakes with electric speed brakes would probably cost at least $20k ( including the upgrade to an Aspen 1000 MAX) but would get me a vacuum-less plane and an upgraded, stand-alone electric AHRS capable Aspen. 5) I will stick with the vacuum system and replace the pump as needed.

The newer model Aspen?

Yea....a bit of venting proceeded the actual issue. I would like to eliminate the vacuum system but want to retain speed brakes. I realize the cost of a vacuum pump is negligible compared to electric Monroe Speed Brake with R/R but want to explore all possibilities to make an informed decision. The coupler just added to the frustration of a newly installed vacuum pump failing 10 minutes after install.

Many first time Mooney buyers considering turbo models are told to be concerned with the costs of running a turbo and the associated heat damage. I am here to tell you the real cost of running a Continental with direct drive accessories are the frangible couplers. Recently, my vacuum pump failed. I have already moved into the glass environment with an Aspen 1000 for my PFD. The ONLY thing keeping me from scrapping all the vacuum related stuff and going all electric are my speed brakes which are vacuum driven. Yesterday, I departed for a quick flight to my mechanic for a pump swap. Immediately after takeoff, I noticed my volts remained at 12.6. During the 20 minute hop, the volts varied between 13.8 and 12.2. Of course, My Aspen battery backup kept popping on and off. Meanwhile, I have the flashing Low Vac light and the Low Volt light. Mechanic swapped the pump and tested and ordered a coupler. Took off for 20 minute hop back to home field and now the volts are pegged at 12.0. Low Volt light flashing so I shed the load and turn off the strobes then the Low Vac starts flashing and the gyro rolls over....replacement pump failed. The Aspen is working great so no danger...clear VFR with the field 10 min away....then the Aspen goes TU with CHECK PITOT HEAT warning...If I had been in IMC this would have been serious (and yes, I realize the Aspen can only be certified for no vacuum with the Battery Backup unit which is yet to be procured). I'm now wondering if all of these flashing lights and red cross screens are inter-related. I can't turn on the Stand-by vacuum due to no electricity being generated so I can't get my vacuum-driven AH back and I hit the Pitot Heat on the off chance that somehow some moisture got into the pitot and froze and that worked, the Aspen came back. Then I realized that all these months when I started up the volts would slowly climb from 12.2 to 13.8 had to be a slipping coupler which was slipping more and more hence my first sentence. So after this lengthly description of my day, yesterday, I am back to the original question, is there an STC to replace vacuum-driven speed brakes with electric ones in the M20K model?

I was flying my bi-annual with my CFI when we practiced an engine out landing. I dropped the gear as I would in a simulated off-field landing and then executed a go around. The gear wouldn't retract...nothing. I used the emergency pull cord and got the gear down for a safe landing at my mechanic's field. He jacked it up, pulled the belly panels and found the problem...bad and corroded leads which he cleaned up and tightened....problem solved....check for loose connections and or a short due to corrosion....that is the low hanging fruit and relatively cheap to solve before moving to the more expensive stuff.

Agreed! Engine management is more an art than science (though it's based on science). I ran a flight yesterday (with dog and wife so stayed low) at 11,000. 2480 RPM, LOP, 7 gph, TIT at 1550, highest CHT at 320, highest EGT at 1520, 22 MP with cowl flaps closed....TAS was way low at 104 kts but had a push so GS was 140 kts.....engine setting combo's seem pretty limitless based on the mission at hand.

Why aren't you using full power during climb? If you have an intercooler, you are limited to 36-37 inches of MP but that is a lot better than pulling back to 30 inches. I climb at full power with full open cowl flaps, full rich and maximum RPM. The TIT sits in the higher 1400's. Only after hitting the lower teens will you see your temps start to climb but with fully opened cowl flaps, you should not exceed 380 on CHT's unless you are climbing through 20,000 ft where the turbo has to work really hard and throw off lots of heat. Once level, I go LOP and dial in 2500 RPM. I will stabilize at 9 GPH around 30 inches of MP with my hottest CHT at 320 . Cowl flaps can be reduced to trail although temps will climb a bit but usually not above 360. TIT usually sits around 1580. Temp management is what the K is all about which is why the 252 and Encore came along to simplify engine management. I don't fly with fully closed cowl flaps since temps go higher than I want but flying them in trial works albeit at slightly higher temps.

Don't run an intercooled turbo at 40 MP, you are overboosting the engine. My typical max climb power is limited to 37 inches due to intercooling. Usually, I cruise at 10 gph running the engine LOP. Hottest CHT's are around 320 unless I am in the higher teens where the turbo is really working and glowing cherry red...then I can see 365-375 on the hottest. Enjoy your K...it is a great traveling machine!

Thanks all for the thoughtful responses. Having read through these a couple of times, it seems that my desired objective can be accomplished but would be less than ideal and not elegant. I failed to mention that both headsets are running off ships power with the Bose pin connectors. We do have jacks side by side with the pin connectors but also like the "no battery required". The X is outdated but still a nice headset and worth more than the $250 credit Bose offers against a $1200 pair of A20's. Ideally, a wireless cockpit would be the gold standard and we are getting there slowly. I think I will wait for the next iteration of wireless technology implementation and see what might fall out in a new generation of over or in-ear communication devices. Thanks again for a great discussion!

I have a pair of Bose X and Bose A20's for my wife and myself. I have been trying to find a link for the bluetooth upgrade and have not had any success. Does anybody have a link or can direct me to a website? We are tired of cords, in general and one less for the audio input from my phone would be worth the money for the upgrades.

Thanks Art...has anyone else used them and if so, what was your experience?

I have an appt with Chandler Aviation in early Sept for a patch. They don't do strip/reseal...only patch and they won't warranty the patch. I found the only two strip/reseals are in MN Weep No More and Wet Wingologists in FL. If someone knows of a reputable third shop, I would like to hear about it.

LOL! When you can afford a million bucks for a "toy", you don't need no stinkin' insurance! Seriously, the Evolution is a different animal than the Acclaim. Composite versus metal, Turbine versus piston, pressurized versus unpressurized., experimental versus factory built...just a totally different animal. Still, cruising 273 kts on 23 gph of Jet A after a brisk 4000 ft/min climb to altitude all in the comfort of a pressurized cockpit is titillating, to say the least. But this is a Mooney forum so I will say the Acclaim is a beautiful machine and I really think they got some things right but Cirrus keeps outselling it...some say its the parachute, others say the UL...it is certainly not the speed!

I highly doubt it...if I am reading this correctly, Jonny Pollack is the current owner of Mooney and is working hard (some might say struggling) to keep things running smoothly on a significantly slimmed down business plan. The Factory Service Center has re-opened so you can get maintenance done and he is working to improve the parts side of the business where the future looks brightest. Mooney has such a large (and aging) fleet of Mooneys that parts would seem to be the smartest and quickest way to profitability. No plans to re-start aircraft production, at least for the foreseeable future, which is probably smart. Mooney missed the market for composite, pressurized light turbines. At $840k for a new Acclaim, they are near the price point for a used Lancair Evolution that flies higher, faster and is pressurized. If they ever do re-start production, I hope they start with an entirely new design because continuing to flog a 50 year old design, no matter how good it was can only get you so far. No flames, please, I love my K and don't think there is any other factory plane that gives me a better bang for my buck but if I had $840k to spend on a new Mooney, I would search the couch for some loose change to opt, instead, for the Evo....

Some more background; According to the logbook, I flew the plane to Wilmar in Aug 2007 for a full tank strip and reseal. It was there for about three weeks before I headed back to pick it up. I have left a VM with Paul but haven't heard back from him yet. I agree that 15 years seems pretty light for a tank seal to last....the original factory sealant lasted 27 years. Unfortunately, the right tank is the leaker (as it was in 2007) and it is staining along the entire joint which is just above the right gear door cover so this isn't a light seepage. I would admit that any extremely hard landings could have broken the sealant but honestly, after 20 years of flying this plane, my landings, while maybe not squeakers all the time, are not drops from 5 feet up.

I had my tanks resealed by Wilmar about 15 years ago. I noticed the right underwing seam by the landing gear is staining. Does anyone have any recommendations for a good resealer near AZ? I don't want to travel too far if I don't have to...

The LB upgrade is more desirable for a buyer and the LB definitely runs cooler. I saw around 40-60 degree drop across my cylinders going from the GB to LB. I ran the GB LOP and up high, I had to work to keep the hottest CHT below 380 degrees. The LB running LOP at the same altitudes see the hottest CHT running closer to 335 -340 degrees. On an earlier post, I commented that the overhaul after parts replacement worked out to the same price as Continental was asking for a reman...around $55k. At the end of the day, it's your call. My old GB was still running and had decent oil analysis but it was leaking oil and started having small "hiccups" that required shop visits and planted small doubts in the back of my mind on whether I would trust the engine on longer flights.....Once I made my decision, it was "balls to the wall"!

Agreed. You cannot legally fly the plane without an approved TIT. I have a JPI 900 which incorporates an approved TIT and an entire engine management system including RPM and MP. The Intercooler and Merlyn is about the best combo for the 231 but requires engine management...especially with the Merlyn. I typically don't fly with more than 28 inches of MP. The intercooler essentially provides a more efficient boost by cooling the air so you must reduce your MP to compensate. I am surprised a certified flight instructor even flew without a TIT but he was correct to be concerned about overboost. I fly LOP and find my hottest CHT's in the low 300's unless I am up high where the turbo is working hard. Usually set up 2500 rpm and run about 9 gph. Up high, that trues out at about 175kts. I recently put a vernier throttle in which makes managing the Merlyn much easier.

Thanks Eric and all other commentators. I may give Paul a call just to get his thoughts since the tanks were completely stripped and resealed by Wilmar and haven't been touched since.

nope...generally keep tanks filled and always hangared.....

He said it is a weep...not dripping on the floor. It follows the seam and I haven't noticed it

My mechanic just informed me that my left fuel tank has started a small leak. Go figure right after I had it painted! Ten plus years ago, I flew the plane to Wilmar in MN and had a full strip and reseal on both tanks. At the time, that was the easy decision since the tanks were leaking pretty good. Even then, there didn't seem to be very many good solutions for patches. I believe Wilmar is no longer in business and even if they were, I highly doubt the warranty would extend out this far. Does anybody have any thoughts regarding sealing fuel leaks these days?