Jerry 5TJ

Before you sink a lot of money into an electromechanical altimeter, consider putting in an Aspen or Garmin PFD. That may be a path to integrate the autopilot and altitude preselect functions at about the same price as the KEA346 / KAS297 system.

Another approach to Alternator conversion -- When the time came (engine ~ 2150 TT) in my 64 "E" I elected to buy a 0 SMOH engine from Lycoming. I specified the alternator version of the engine, then I only had to buy a new alternator controller, circuit breaker and a few misc. items rather than the whole conversion kit. The generator went back to Lycoming with the old engine core. This approach was lots cheaper than doing a stand-alone alternator conversion. The 70A alternator on the new engine came on-line at about 1200 RPM versus about 1700 RPM for the original 50A generator with its mechanical "regulator."

Here are some more flight data points for my M20C. The figures for 4,500 feet are a good standard comparison point. Those data taken with mixture full rich, 2,500 rpm and 25" manifold pressure. Note for you mathematicians: The quadrant speeds are rounded in this chart, but the average speeds shown carry the proper number of significant bits from the collected data.

Each check was performed with the cowl flaps closed, CHT 50 to 100 degrees rich of peak, overhead air scoop closed, and the plane stabilized on course with no altitude fluctuations, at a flying weight of about 2200 pounds. The speed is GPS ground speed, and in each direction I averaged four to six readings in a 3 to 5 minute run. I have more recent data, and will update this post when I get those data from the notebook to the spreadsheet. This is one airplane's data, taken by one pilot. Your mileage may vary, as the saying goes. I took this format from Paul Smedshammer’s site http://www.coreutilities.com/mooney/Speed.html which lists speed data before and after various modifications on his 1967 M20F. He takes all his readings at 4,500', 2,500 RPM and 25" MP. That's a good basis for plane-to-plane comparison, too.

I have data that I have taken for my 65 "C" in flight -- GPS-derived TAS versus altitude, OAT, MP and RPM. I don't have fuel flow information.

ASIDE -- gee, that's interesting. I thought the FAA examiner was along for the ride, not as required crew, so why does he/she need any controls at all? Of course, the examiner may have personal requirements other than FAA regulations. Or, are you going to be sitting in the right seat as the CFI candidate? In that case, yes, you would want brakes over there.

Back when I lived in Maryland and had an "E" model, I went cross-country flying one fine winter day, CAVU but cold. About an hour into the flight I tried to switch tanks. I found that some slush from my shoe had gotten down into that cup in which the fuel selector sits, and at altitude froze solid. The fuel selector handle was embedded in half an inch of ice, and there was no way to defrost it in the air, and no way to use the 26 gallons of 100LL on one side. So, I landed at a nearby airport, had the plane put in a heated hanger and it was all dried out the next morning. After that I cut a square of carpet and kept it over the selector when the plane was on the ground, so that nothing could fall into that cup.

Another viewpoint: My "C" got harder to start last spring in morning temperatures in the 40s, which is cold here in Northern CA. Six or eight flights in a month, all with the same issue—it was just harder to start the normally quick-firing engine. I attributed it to that spell of cold SF weather. Then one morning the left magneto was totally dead at run-up. Both had 500 TT, so I sent both magnetos out for IRAN. Once back, the plane started as of old, just fine.

I have a different reading of the 2009-22-03 AD than the prior poster. I do not think this AD resets the clock on propellers which have had ECI inspections prior to the effective date of AD 2009-22-03. On page 11 AD 2009-22-03 reads Compliance (h) You are responsible for having the actions required by this AD performed within the compliance times specified unless the actions have already been done. I believe that the last few words of that section are key -- "unless the actions have already been done" -- that the 50 hour clock does not start anew if you have already done ECI. My prop, for example, had an ECI about 15 operating hours ago, and before November 12, and so it still has to be inspected per language on page 12 of AD 2009-22-03: (m) Within every 100 operating hours TIS after the last propeller hub ECI, perform repetitive ECIs of the front cylinder half of the propeller hub for cracks. so I will have to, as was true before, get another ECI performed on the prop after another 85 hours operation. I don't believe the AD requires my prop to be inspected again in 35 hours TIS. Under this new AD, the next inspection is only required after 100 hours service, NOT 100 hours OR 12 months, as it was under the prior AD, so this AD provides some relief to those who fly fewer than 100 hours annually.

Best Mooney tool .... is a checkbook and suitable bank balance. However much you have in your account, that's a good start.

Since the 2006 AD came out, I have done 3 ECI, the first two cost $200 each and this year's was $250. It is a minor nuisance to fly to the shop and have the inspection done on the ramp.

Regarding the lock -- Attached is another image that shows the pin lock better. When the thumb button is pressed the “J” shaped pin moves to the right. The pin moves out of the locking groove on the Johnson bar's handle. That allows the sliding handle to move down, towards the viewer in the image, and the bar can swing towards the floor. The “sliver” to the right in the earlier image is beyond and above the block, It is a piece of the lower panel trim, and is not part of the downlock block assembly. So, in answer to one question -- the pin is the locking mechanism, not the “sliver” thing. Re prices -- I did get a price for the uplock block from LASAR, and it was about $250 for the part (don't have the quote in front of me, so that's an approximate figure). That price is for the machined aluminum block, it does not include the button, slide locking part, or the microswitch assembly. I was told you salvage those parts from the old unit and reuse them. Since the new block will hold the Johnson bar in a different location (albeit slightly) the landing gear preloads may change. At the least, it seems prudent to check them after installing a new downlock block, and before lowering the Mooney back onto its “feet.”

What are the wear limits on the uplock block? Photo is of "C" model with 4000 hours, apparently the original uplock block. Taken in flight, the view is from below and shows how the steel top of the Johnson bar has worn a groove in the aluminum block's ramp. The hole is worn oval, and the end of the locking pin appears worn to a bevel, too. It feels secure when I latch it, and give a big "heave ho" test on the handle as part of the GUMP check. Questions for the forum: (1) Is there a wear limit specified anywhere in Mooney literature? (2) If/when the block is changed, does the gear rigging tension change much? FYI -- the rectangular tab visible in the center of the uplock hole is the gear safe light switch. It toggles a microswitch to light the red and green gear indicator bulbs.

If you really want to save weight, buy a composite tank. They are super in volume-to-weight ratio. But they cost a lot; like a nice bicycle, you pay for the weight you don’t have to carry. Those old, low-tech 3AA series steel tanks are cheap. I have one with a 1960s manufacturing date. It has been hydro tested any number of times, most recently last week. It holds 50 cu feet and cost me $5 at a pilot swap meet plus a hydro test. Yes, it weighs 32 pounds, but it will give 40+ man-hours with an oxymizer at 12K feet. Cost to fill is $40 at the airport -- so that's $1.00 per hour. I go on O2 at 9000’ day and 5000’ at night. Yes, you can get your O2 bottle filled at the scuba or welding shop, but make sure they put in O2 and not air or Nitrox. No, that's not a joke -- I recall an accident report where the NTSB found the O2 bottle contained 21% oxygen, to wit, compressed air. Reference NTSB IAD97FA060.

Maybe the question should be: Why are our airplanes so cheap? If Mooney produced a new M20C today, it would probably sell for at least $300K (in 2009 dollars) , not the $40K (in 2009 dollars) or so it is worth used, but heck, they're over 40 years old. If I were to buy vintage 1960's avionics they would be darn cheap, too (even in 2009 dollars they're worthless). My point is the obvious one -- we're putting new avionics into our antique airframes, and we should not compare a new-in-2009 radio with the used price of the old airframe. Elsewhere on this forum are some original Mooney factory invoices from the 1960s. It is interesting to see how much the optional avionics added -- more than 15% was not uncommon for a "full panel" with VOR, ADF and Brittain autopilot. At today's hypothetical M20C $300K base (in 2009 dollars) that woud be over $45K (in 2009 dollars) -- just about the price of a nice panel upgrade today.

Many steel O2 tanks can be recertified every 5 years indefinitely, at a test cost of $20 (current 2009 prices). Some lighter-weight steel tanks, and composite tanks have service life limits. In the USA, the DOT regulates these tanks: Type 3AA 1800 steel cylinders must be tested every five years. They have indefinite service life provided they pass inspection criteria. Type 3HT 1800 steel cylinders must be tested every three years, and they have a service life limit of 24 years, after which they must be destroyed. Type 3AL seamless aluminum cylinders require test every 5 years and generally have a 15-year service life. Composite cylinders (often Aluminum with Kevlar wrap) must be tested every three years and have a 15-year service life, after which they must be destroyed. Another point on O2 costs -- most shops charge a flat rate to fill your tank, be it large or small. So I have a big one, oxygen tank that is, and that makes my O2 at least twice as cheap per hour as the smaller tanks more commonly seen in portable systems.

I have significant but far from total hearing loss in both ears. So, I have a SODA - a Statement of Demonstrated Ability - issued by the FAA via my AME. It permits me to hold a Class II or III medical, and requires I use "hearing amplification devices" such as headsets or hearing aids when flying. It might be possible to get a SODA for Class I, I don't know, I never tried. Talk to your AME. The SODA is issued once, and you present it at each medical exam.

Voltage Regulation During Flight I recorded the voltage during a "typical" 45-minute flight in my M20C. The DVM recorded 2 samples per second; there are just over 5000 points in the first graph. Overall comments The generator is only "on line" when the engine is running >1600 RPM or so The voltage is noisy even in steady state conditions The voltage of the bus depends strongly on the applied load If you look closely -- see the "First 5 Minutes" expanded graph -- you can see the mag checks which reduced the RPM from 1700 by about 100 RPM and the voltage about 1/2 volt. After run-up, back to 1000 RPM and the voltage fell back to ~ 12 V. During flight I turned on various loads -- for example, at 15:44 local time I turned on the landing light (250W) and the voltage dropped. At 15:49 I turned the landing light off and the voltage increased again. Background Information Voltage was measured at the radio master bus The plane has original-type 50A generator It has an original-style mechanical voltage regulator I notice that the battery appears to be reaching full charge only near the end of 45 minutes of flight -- fully charged is a voltage of about 2.35 volts per cell for a lead-acid battery, or 14.1 volts. Does anyone think that changing to the newer solid-state type generator regulator (Zeftronics, for example) will improve this situation and reduce the noise "hash" seen here?

One of the top assist springs broke on my M20E a few years ago. I noticed it right away as the manual gear forces increased greatly. I could still operate the gear but it took a real heave-ho to bring it up. It came down real fast, though.... Lasar at Lakeport CA had the spring in stock. They also have the Mooney tool -- a big long lever with the proper fittings -- to install the thing. I was happy to watch rather than help as it took two strong and experienced A&Ps about half an hour and a lot of hard pulling to get the new part installed.