PT20J

Good question! To be airworthy, the airplane has to conform to its type certificate. The Supplemental Type Certificate that allows installation of the speed brakes modified the original type certificate. If they were still installed, you could just mark them inop. But, if you remove them you would either need to return the airplane to its original configuration, or get a ferry permit.

Ferry tanks are not designed for permanent installation. Think you’d have to operate on a ferry permit.

Don’s right. Your A&P should handle the details. Legally the airplane would be considered unairworthy in its current state and without a ferry permit you might find you have no insurance coverage.

It was a four course range that used tones. VOR transmits an omnidirectional reference signal and a rotating directional signal and the phase difference between the two defines the radial. The antenna is a dipole and each whisker makes up one half of the antenna. It is not two separate antennas connected together.

VOR, localizer and GS are all horizontally polarized - that’s why the dipole antenna spreads out horizontally. The blade and towel bar style antennas are split on each side of the fin. So, it probably works fine to reverse it. Still, the is no way to be sure without doing it and then measuring the change in antenna pattern. There must be some reason Mooney mounted it the way it did and it would be good to know that.

My 78 J had V antenna facing forward. It probably doesn’t matter as Piper and Cessna mount them the other way around. But still, there may be some reason, so if you change it you’d be the test pilot and it might invalidate IFR certification. I’d check with a knowledgeable radio shop or LASAR. I wouldn’t expect any drag reduction as it will still be two rods sticking in the slipstream. Round cross sections are draggy and it doesn’t matter if they face forward or back. If you want a better look and lower drag, get the “blade” style antenna.

I’ve use the Scratch Off kit. Works well. Also works well on minor scrarches on auto clear coat, plastic headlight covers, and scratched DVDs. When I ran out of kit abrasives, I used Novus scratch remover 2 and 3 from a local plastic store.

Thrust = drag. To go faster, you have to increase thrust or decrease drag. As noted, decreasing drag is more efficient. Mooney started out with a design that packages 4 people in the smallest wetted area (with a cabin width greater than the Bonanza). The aerodynamic cleanup for the 201 got the low hanging fruit in drag reduction. When Mooney ran out of aerodynamic tricks, it did what everyone else does and went to bigger engines.

Sounds like some basic troubleshooting is in order. Separate mechanical issues from electrical. Two most likely issues are mechanism so stiff that trim servo stalls, or weak trim servo. With electric trim off, can you manually move the trim wheel easily from stop to stop? If not, find the source of the problem. Clean and lube easy to get to stuff first. The trim carrier bearing is not that hard to get to and should be serviced but is not likely the cause of the problem. Most heavily loaded parts are the jackscrew and associated thrust bearings. Does alt hold work without tripping trim switch/breaker? Put in alt hold and vary airspeed with power and this will exercise autotrim. If this works, you know that the trim servo is good and the problem is in the manual electric trim either in wiring, switch or the KFC 200 flight computer. Skip

This is a lot less expensive than the 3M UHMW tape that Mooney specifies. I bought some to try but haven’t tried it yet. https://www.amazon.com/gp/aw/d/B00823JBVG?psc=1&ref=ppx_pop_mob_b_pd_title Maintence Manual has procedure for adjusting gear doors flush.

The Mooney trim system adjusts the angle of incidence of the stabilizer as I'm sure everyone knows. The stabilizer incidence moves through a range of about 6 degrees for the M20J. It's not enough for the full trim range required, but it's impractical to get more range from the stabilizer -- it already takes a lot of rotations of the trim wheel just to get 6 degrees. The trim assist bungees bias the elevator to deflect along with the stabilizer movement to increase the effectiveness of the trim system. The interesting question is why isn't the elevator faired with the stabilizer in cruise? Back in the early '90's, Lowell Foster (engineer at Mooney) told me that he thought this was a side effect of lengthening the fuselage for the F and that LoPresti had noticed it but calculated that it didn't contribute enough drag to make it worth the effort to fix it. But, Lowell's response to a lot of questions was that no one really knew since there had been so many management and staff changes in engineering over the years that the reason many things were the way they are had been lost. So, if Lowell was right, the C elevator should be more closely faired than the F or J. It makes sense that lengthening the fuselage would cause a downward deflection in the elevator because the longer moment arm would require less tail down force to create the same pitch moment. And I can see that the increase in drag would be negligible because the deflection is so small and offset by the lessened tail down force. Still, I've often wondered about it. Skip

I’m curious about something. The M20J has a 5 deg or so down elevator deflection when trimmed for cruise. I wonder if the shorter C does the same thing. Anyone looked back at your tail?

Anthony's comment got me thinking about how grease wears out. Does it really turn to rocks? I found interesting information about bearings and lubrication on Tinken's website. https://www.timken.com/pdf/5892_Bearing Damage Analysis Brochure.pdf. Always fun to learn new stuff! Skip

The entire trim system should be lubricated during the annual inspection (with the exception of the front gearbox and the jackscrew thrust bearings which are not accessible without significant disassembly and are generally dealt with on condition). The Maintenance Manual calls out low temperature oil for the U-joints (there shouldn't be grease on these). The jackscrew is heavily loaded and needs to greased with the proper grease. One of the few times I diverge from the manual is in the choice of lubricant for the trim wheel and trim servo chains: the manual calls out grease which makes no sense for a chain since it won't easily get into the rollers -- I use the same oil I use for the U-joints. Also, don't forget to put some oil on the trim wheel shaft and bushing and check the tension on the chain. This bushing is a common wear point leading to a wobbly trim wheel. I generally use electric trim, but I always manually reset the trim to takeoff position after landing so I can feel how the mechanism is working. Skip

A long and interesting discussion. I'll try to summarize the facts: 1. 14 CFR Part 1 states "VFE means maximum flap extended speed." If only a single VFE is specified, then it applies to all flap extensions. No other interpretation makes sense because it would require the maximum speed for other than full extension to be unspecified. 2. The TCDS defines the conditions for airworthiness. Pilots generally do not reference the TCDS, so the airworthiness conditions pertinent to operation are included the Airplane Flight Manual Limitations section. This section is regulatory and binding on the pilot. 3. Flaps do four things: 1) They increase CLmax while reducing the angle of attack at which CLmax occurs, 2) They decrease the angle of attack at which zero lift occurs, 3) They increase drag, 4) They create a pitching moment. 4. Mooney flaps are more effective at reducing stalling speed than flaps on many similar GA airplanes. To prove this to yourself, look up the Vs0 and Vs1 speeds (calibrated) for various airplanes. (Or, find the other thread where I did this). 5. The primary purpose of flaps is not to slow down. However, they do create drag. Should you forget to raise flaps after takeoff, your first indication may well be in inability to attain cruise speed. 6. There is no mechanism in any Mooney to raise the flaps in the event of an overspeed. Skip

I have a Battery Minder and run my avionics in the hanger and it works fine.

Not really a money issue for me - just want to understand it. Talked with the radio shop today and issue may be that I’m out of ports on 430W. Last owner didn’t get configuration info or wiring diagrams for 430W/Aspen Installation. I’ll find out when we open it up for GTX 345 installation. I get everyone’s gut response. Was hoping someone had researched this and had data, but now believe data is unavailable.

There's lots of advice about this depending on who you ask. Some regimens are pretty complicated; some are pretty simple. I thought Mike's article cited above pretty much nailed it. I recently put a factory rebuilt engine on my J and it seems to be doing fine just keeping three important points in mind: 1. Use the recommended break-in oil (a warranty consideration) 2. Run at high power for the first few hours to seat the rings and don't do low-power descents, stalls, and touch and goes. 3. Keep the cylinder head temperatures under control. An engine from the Lycoming factory (new, rebuilt or overhauled) will have been run in a test cell for an hour under varying conditions designed to test the engine and get the break in off to a good start. I instructed at several flight schools over the years. After a couple of hours test flying a new engine, the maintenance department would release it to the flight line and the only instructions were, "use mineral oil and don't do touch and goes." I've flown seaplanes for two part 135 operators and again, after a couple of hours of test flying, maintenance turns it over to the line pilots with the only admonition being to use mineral oil. These engines did just fine. On my engine, I never had high CHTs nor did I see them decrease significantly during the break in. Break in is considered finished when oil consumption stabilized which means that it it burns X hrs/qt consistently. Though Lycoming doesn't require it, I changed the oil and filter after 10 hours and will change to AD oil after another 25. I think the process can be stressful because it's something that we don't do often, there's a lot of money involved, and we don't want to screw it up. But, in the end, it's not magic. I'm sure you'll do just fine. Skip

Well, I’ll probably do it. I do appreciate all the opinions. Problem is, being an engineer, I was hoping someone had found some data. Without data, it’s a subjective emotional decision, and I hate making drcisions that way. I did some searching, but there is precious little data about the effectiveness of ELTs at all, let alone adding GPS. The “problem” is that there just aren’t enough crashes (thankfully) to have a large enough data set to anslyze, and ELT effectiveness data is not well captured. Years ago I recall some study concluding that the ELT didn’t even activate about half the time. That’s why I like flight following so much when I’m VFR.

OK, I get that. They put a new ELT antenna on the top near the baggage door rather than installing it under the dorsal fin. This also runs the cable across the tailcone to cabin junction. So there is a chance that the antenna may become disconnected during a crash. I'm assuming that if you activate the ELT before impact, that it would broadcast the GPS position -- is this right?

Well, I kinda figured that. But, it would help me get a clearer understanding if I knew the details of how it works. Don't the satellites locate a 406 ELT pretty precisely even without the GPS?

That's really interesting. Most of my experience is with Js, so I don't know many details about Ovations. I found a Oct-94 M20R service manual online (http://www.softoutfit.com/static/refs/smm-wiring.pdf) and section 27-50-00 doesn't mention this feature -- it shows essentially the same flap mechanism that's been used ever since they went electric. Likewise the Rev G 03-2000 M20R POH (http://www.softoutfit.com/static/refs/poh.pdf) system description doesn't mention this feature (though all the system descriptions in the POH are pretty lean on details). Does anyone know if this is the latest service manual or have one for a 2006 or later Ovation? I'd really like to know if Mooney added this feature (The DC-3 had this). Of course, if Mooney was to mess around with the flap actuating design, my vote would be to add an up lock so you didn't have to step over the darn thing (and worry about your passengers stepping on it - I leave mine down after shutdown to avoid that). Skip

The previous owner of my '94 M20J had a ACK E-04 installed, but didn't connect it to the GPS. I'm getting a GTX 345 transponder installed soon, and I'm thinking that might be a good time to connect the GPS to the ELT since the radio shop will have to mess with the GPS connector anyway. I'm sure some of you have thought long and hard about whether the GPS position really increases the likelihood of being rescued. What do you think: is it worth the cost and trouble?

Seems like the software fix and the AD crossed in the mail. Now that the government is back up and running, It should settle out shortly, I imagine.

Question for those who extend partial flaps above VFE: How do you determine a safe maximum speed for partial flap extension? The next higher limiting speed in smooth air is VNE. I mean, the AFM doesn’t say you can’t extend partial flaps at VNE, right?