PT20J

The ELT antenna should be mounted on the top of the aircraft for crash survivability and improved reception by the satellites. The issue is that placing it in close proximity to another vertically polarized antenna of similar length can change the radiation characteristics of the other antenna even though the ELT is not transmitting. The antennas you want to stay away from are the VHF comm antennas. That said, it is almost impossible to mount all the antennas for all the stuff we cram into small single engine airplanes in a way that meets all the manufacturer’s distance requirements - there just isn’t enough real estate. Do the best you can. Radio waves follow the inverse square law, so even a few inches can make a difference. You might talk to a couple of avionics shops about their experiences. @Baker Avionics has been really helpful. Skip

If the components were original, weights should be in the equipment list. If they were added later, there should be 337s. If you have all the old W&B computations, weights should be available there. Skip

I don't have the IPC for your airplane but 53-30-00 for my J lists all the screws. Some are PK (sheet metal) and some are various sizes of machine screws -- you just have to figure out which ones go where as the IPC is not very clear on this. There is a theoretical corrosion issue with stainless steel, but there is so much more area in the aluminum (anode) than the stainless (cathode) that it's not really a problem. https://www.bssa.org.uk/topics.php?article=89. I use stainless steel screws and when I remove them I put them in a zip lock bag with some WD-40 (or LPS3 or Corrosion X -- it doesn't really matter). They go in easily and come back out easily. A common mistake that makes them difficult to remove is over torquing them. Skip

I used to have an engineer working for me that was a skydiver. Whenever we would go on a business trip, he'd scout out the nearest drop zone and bring his rig which he didn't want to check as baggage, so he would carry it on. Got lots of interesting comments as he walked down the isle during boarding carrying a parachute. He always replied that there was no way he would fly on (insert whatever airline we were flying) without a parachute. Skip

If you weren’t so negative, you wouldn’t need a parachute

Illustrated Parts Catalog. It’s not an STC. It's a Mooney design change documented in the Type Certificate Data Sheet (TCDS) and retrofittable to certain serial numbers by Service Bulletin. Skip

Maybe -- it would certainly weaken the argument and it's a good question for an attorney. I can't imagine any company I deal with doing that so it begs the question if there is more to the story....

A few comments. 1. Mooneys generally have very well engineered power distribution and grounding. Look at the wiring diagram in the Service Manual for details. 2. Electrical buses are BUS not BUSS (even Mooney documentation gets this wrong sometimes -- take it from a EE: Buss means "kiss" -- look it up ) 3. If you want to have some fun, bet someone your favorite beverage that you can turn the radios on by pulling a CB. Mooney realized that an avionics master was a single point failure and wired the relay as normally closed. The Radio Master powers the relay open when it is in the OFF position and removes power from the relay when in the ON position. So turn on the Master but leave the Radio Master off. Then pull the AUX CB and the radios will power up. Skip

This seems pretty simple: 1. Work done you didn't authorize is not billable and could be construed as tampering. 2. Tampering with aircraft may be a crime in many jurisdictions. Skip

I bought the carpet and side panels from Airtex -- didn't think to ask them about the insulation. Curious what Airtex's price was? My Airtex order got hung up when the factory was closed for COVID and so I didn't have the windlace when I needed it. Bruce Jaeger came through with some he has made. When I got the Airtex windlace, I compared it and I actually like Jaeger's better. It is a softer vinyl material and Bruce puts a double sided tape on it which holds it in place when installing all those screws. I used Airtex windlace when I redid a '78J years ago and it's a good product -- I just like Bruce's a little better. But, I've got enough Airtex windlace now to do a main door and baggage door if anyone wants some. Jaeger also has a edging to go around the windows that is soft rather than the harder original material. I really like it, but you have to glue it on with some clear RTV (which Bruce supplied). Skip

I just did that to my '94J. It came from the factory with the metalized mylar/foam on the sides walls but fiberglass in the ceiling and baggage compartment. I bought the metalized mylar/foam from a MSC that had a roll of it from Mooney. It's 1/2" thick with pressure adhesive backing and comes in a 54" wide x 50' roll. I bought 11 feet of it at $30.55/ft. I weighed it and it was 2 lb heavier than the fiberglass removed. Skip

I had the same problem until I finally figured it out. Pull up on the seat back T handle and pull forward on the seat back until it rotates forward freely so you can work on it. Undo the velcro. Then, run your fingers around the opening at the bottom that was closed by the velcro and work the edges of the opening wider so that you can pull the upholstery and cushion (they are glued together) off the frame. There is one last step in Paul's @gsxrpilot instructions if you are going to put any significant weight on the seat back once folded down. Remove the hitch pin Lee @laytonl mentioned and pull the frame off the arms. Then replace it into sockets in the frame that are nearest the carpeted top. This allows the frame to fold down fully into the seat well. The POH instructions reproduced by @elimansour are factually correct, but only made sense to me after about half an hour of fooling around in the airplane and trying things and rereading them and trying something else. Skip

The problem with the capacity test is that it takes time and automotive shops want to move stuff through quickly so they need a quick and dirty test to find really bad batteries. I have a 5 year old battery in my Subaru airport car that sits a lot between uses and the shop where I recently had it serviced tested it with some 2 minute tester and said that it has 60% of it's life left. Do I believe that? Surrrrrrrrrrrrrre. Car batteries always last 12 years, right? Skip

I use my dad's old hand-me-down monkey wrench -- much prized by steam locomotive engineers. Skip

Here's the letter from Aspen: Aspen Pro MAX Evolution 2000 and Evolution 2500 Systems Dear Valued Aspen Customers: Today, the FAA issued Airworthiness Directive (AD) 2020-16-08 effective August 17, 2020, regarding a potential reset event of Aspen Avionics' MAX series displays. Be advised, the FAA approved software v2.10.2 in March 2020 addressing the infrequent but potential reset issue of Evolution MAX series displays and we have successfully implemented this software change for affected customers. These design changes are defined in the 900-00003-001, Revision CC, EFD1000, and EFD500 Software Version 2.X installation manual, dated March 2020. Aspen Service Bulletin 2020-01 describes the v2.10.2 software update procedures. This AD only applies to Evolution 2000 MAX and Evolution 2500 MAX systems with software v2.10 or v2.10.1 AND if any of the required backup instruments (ASI, ATT, ALT) have been removed. This AD is not applicable to MAX displays that have been updated to software v2.10.2 or any legacy Aspen Avionics displays. Please contact your Aspen Authorized Dealer if you have not yet updated your MAX displays to software v2.10.2.

Well, the original price in the 1992 SB is listed at $1750, so it has less than doubled in 28 years. Careful examination of the IPC will show that lower tube part number 340117-119 in earlier models has a .035" wall thickness and was changed to part number 340155-135 with a .049" wall thickness at S/N 24-1686 which is the first S/N eligible for the gross weight increase. Skip

No, the point is that they had a great product and had difficulty with newer technology. That's very common. Sometimes companies recover and sometimes they don't. HP made oscilloscopes but the triggering circuit was really bad. An engineer left HP and started Tektronix with an idea for a better triggering circuit. Tek scopes were so much better that HP got out of the oscilloscope business for a few years. When they came back they had a competitive product. So, you have to keep looking at the current product offerings and not live in the past.

Reviewing this thread, there's a lot of good info, but I don't think we answered your question. Let's see if I can break it down: 1. The purpose of the low voltage annunciation is to alert you that the alternator is not charging the battery. It is set to about 12.5 volts so that it should flash when you are running on battery power only. Thus, the indications you mention are normal. 2. The way to tell the charge state of the battery is by measuring the voltage at the terminals with no load on the battery. The 11.7 volts you measured seems low, but that's with the master on so there is some load and thus you can't really tell anything from that measurement. 3. The only way to tell for certain if the battery needs replacing is to do a capacity test. Most people just wait until it is so worn out that the starter is sluggish. That may be OK if you only fly VFR in uncongested airspace and don't mind the inconvenience of getting stranded at a strange airport. But, if you really need the battery to run stuff for an hour or so after an alternator failure, you should do a capacity test at least annually. Skip

Gill makes great flooded cell batteries. Its sealed batteries weren't so great. I think they quit making them until they re-engineered them. Maybe they are good now. Champion had problems with resistors in its spark plugs. They are now redesigned and are probably just as good as Tempest. Tempest fine wires had problems shedding electrodes. I'm thinking about buying fine wires when I install a Surefly mag. Should I buy Tempest? Things change. Companies learn. Products improve. But people have long memories when a bad product cost them money. Skip

Except for the rare case where an ICA includes aircraft limitations changes, ICAs are like service bulletins: optional for part 91 operations. Most IAs don't bother with them at annual because CBs are always complaining about how much the inspection costs . However, just like service bulletins, it's a good idea for the owner to read the ICAs for installed equipment and decide which are important. Lubricating the speed brakes is one that commonly gets ignored Skip

If it hasn't been flying, has the engine been pickled? If not, the big concern would be internal corrosion. The cylinders could be pitted but the biggest risk is the camshaft which you cannot inspect without some disassembly. As you noted, the engine is beyond the Lycoming 12 year TBO. I would also be very concerned about the airframe and avionics. Mechanical and electrical components do not like to sit. Electrolytic capacitors in radios go bad. Bearings deteriorate from moisture, etc. I volunteer at a local museum and a lot of the airplanes fly less than 10 hours per year. They are all hangared. We usually find stuff that needs fixing at every annual. The mechanic says he'll never be out of work since they seem to break just sitting there. If it were me, I'd look for another airplane. But it this one is really the one you want, I would get a very thorough prepurchase inspection including oil analysis and borescoping the cylinders by someone that knows Mooneys well and knows what to look for, and I would nit pick every little discrepancy (realizing that you won't find them all) and negotiate a deep discount. I would also go into it with a healthy cash reserve tucked away in case it needs an engine replacement and other expensive work. Skip

The aircraft voltage regulator is inop when the master and alt switches are off. The Concord Manual indicates that 11.7 volts is fully discharged if there is no load on the battery. I would turn off the master and verify the open circuit voltage with a digital multimeter at the battery terminals, but it probably needs replacement. Battery life is greatly dependent on how the battery is treated, so claims of x years of service are really meaningless. Things that shorten battery life are: Overcharging (voltage regulator set too high) which boils off electrolyte, and deeply discharging without recharging immediately which causes sulfation. Battery life is extended by keeping it topped off with a trickle charger. Skip

The only way to know the condition for certain is to do a capacity test. Documentation is on the Concord website. Skip

Hey, all you airline guys -- what color are your panel lights?