FLYFST

Negative on the Annual, but thanks for the suggestion. I have experienced MIFs in the past; quite a frustrating reality. Hank Sent from my iPhone using Tapatalk

Thanks for the advise! Hank Sent from my iPhone using Tapatalk

Hello, fellow Mooney drivers. I'm writing to ask for advise from those of you with experience in older autopilots and autopilot servos. My 1990 M20J has an old but well functioning Century 2000 autopilot that is coupled to a Century NSD-360 HSI and GNS-530W. The autopilot meets my mission needs well and I have no desire or plans to replace it. A couple of months the autopilot navigation computer failed while engaged and the only indication was a totally dark computer display, no popped circuit breakers, no adverse indication on the controls. Recycling the autopilot circuit breaker had no effect. Testing by an avionics shop confirmed a blown internal fuse in the computer that was easily replaced. After 3 hours of diagnosis no cause for the blown fuse was found, and the computer was found to be operating normally. Now it's happened again, and the CFII/A&P flying with me has suggested the roll or pitch servo (no yaw damper) may be demanding too much voltage or amperage or both from the computer while engaged. I'm requesting your advise on how to troubleshoot the servos before again replacing the internal computer fuse. After the first fuse failure and repair, the airplane flew multiple sorties with the autopilot always passing the preflight check, and remaining powered (cannot be turned off) during the flights but not engaged for navigation or altitude hold. On the flight with the latest computer failure (expecting another blown fuse but not certain yet), we had the autopilot engaged for approximately 1.5 hours during which we completed coupled ILS and RNAV approaches, with everything functioning well. Towards the end of the flight, with the autopilot engaged in the heading mode and altitude hold, we were experimenting with maneuvering the aircraft by turning the heading bug, and that's when the computer again failed in the same mode, by disconnecting, with a totally dark computer indicator, and no adverse indication on the controls. Recycling the autopilot circuit breaker had no effect. This is why the current thinking is one or both of the autopilot servos may be malfunctioning by demanding too much voltage or amperage from the computer to operate and causing the fuse to blow. After downloading the EDM-830 data post flight and reviewing the 1-second recorded voltage history I found no spikes that could perhaps cause the failure, and the voltage varied between 13.7 and 13.9, with the large majority of the time at 13.9 volts. Any thoughts or suggestions on how to test the servos for proper operation and/or what else may be causing the blown fuse would be most welcome.

Was the gear down indicator also off on the panel, in addition to off on the floor indicator? If so, check the gear down switch in the belly for proper operation. Hopefully a replacement switch for the M20R will be easy to find, and affordable. I found mind blowing prices for M20J substitute switches to the replacement switch of the original switch, when available and sometimes within weeks to months, especially if it’s a Honeywell switch. Buying a used switch may work or not and only delays replacement with a new switch. Sent from my iPhone using Tapatalk

Don’t sell Norm! Have a sleep doctor issue you a CPAP that records data, get at least a month of usage data (check with AME or AOPA medical for guidance on how much), send data along with letter from the sleep doctor saying the sleep apnea is under control to the FAA medical examiner requesting a Special Issuance certificate. It is no big deal to have one issued and continue enjoying your bird. Regards -Hank Sent from my iPhone using Tapatalk

Thanks Jake. I will PM you separately. The unit just went dark after working well during the flight. Resetting the CB made no difference and on the ground I verified the CB works. I have a working spare that is the same model number but different part number and came out of a Velocity acft during an upgrade, so I don’t think I can plug in the spare in my M20J and expect it to work, but may just fry something else. Sent from my iPhone using Tapatalk

Thanks! Probably will need a big prayer and offerings to the Gods of Avionics[emoji41] Sent from my iPhone using Tapatalk

Great, thanks very much. Hank Sent from my iPhone using Tapatalk

Indeed it is, but what I found so far is dated and not very useful. I will keep at it. Thanks- Hank Sent from my iPhone using Tapatalk

Thanks, I know of them but thought they no longer worked on the Century 2000. I’ll give them a call. Hank Sent from my iPhone using Tapatalk

Thanks! I will look into them. Hank Sent from my iPhone using Tapatalk

Thank you for all the efforts Craig and for MooneySpace. The $25 fee is one I’m pleased to pay for all the value delivered. Hank Sent from my iPhone using Tapatalk

Anyone have a recommendation on where to send a Century 2000 Autopilot Computer for repair? My understanding is Century Flight Systems in Mineral Wells, TX is no longer in business. I'm currently investigating sending the unit to Palm Beach Avionics, but would appreciate any other recommendations. I realize given the 25 year age of the unit it would be best for the long term to invest in a new, digital autopilot, and will likely do so when its time for the next upgrade of other avionics, but not yet. thanks - Hank

Thanks Sent from my iPhone using Tapatalk

The M20J Advanced Training System (M20J-ATS) has RH brakes. Try searching for that. If you wish I can post the relevant pages from the IPC that will show the parts involved. You might try contacting Mooney Technical Support to ask if there was/is a kit available to install RH brakes when not originally in the airplane. Sent from my iPhone using Tapatalk

Thanks, does your IPC actually show the P6-24014 or 1EN1-S, and if does for which M20 model? Sent from my iPhone using Tapatalk

Thanks, the 1CH116-6 is the same on the M20J IPC. I am looking for an IPC page like you provided that shows the 1CH1-6 that I think was used in the E, G, and G Mooneys. Sent from my iPhone using Tapatalk

Hello Mooney family, Does anyone have an IPC that lists the Honeywell 1CH1-6 Gear Down Limit switch as a original or alternate installation? My understanding is that switch was used by the M20E and M20K, but I do not know if used in the J and other models in between. My IPC (MAN226, 2003) for the M20J lists only the obsolete Honeywell 1CH116-6 switch. thanks - Hank

Has anyone confirmed that the 1EN1-6 or 1CH1-6 limit switch is a Mooney-approved replacement for the Honeywell 1CH116-6 switch listed in the Mooney IPC? Best research I have found so far was from Skip (PT20J) who noted the 1CH1-6 is essentially the same as the now obsolete 1CH116-6, but that circuit specification stated that one circuit must close slightly before another, presumably to make the motor shut down before the gear light comes on, and the 1CH1-6 does not include that feature. I'm searching for a replacement to the Otto Controls P6-24014 switch that I have and while the 1CH1-6 seems to be viable, I am concerned about the circuit difference that Skip found in the following post.

Thanks for the research Skip! Sent from my iPhone using Tapatalk

Moon_Dog, I've had similar issues with my 1990 J model, and what worked out best was adjusting the switch stop (tab secured to the push-pull rod) so that it contacts the plunger face flat instead of at an angle. My A&P previously tried lubing the plunger with CRC contact cleaner with immediate results that did not last much. As a sealed switch, about the only place the lubricant could be of some effect is on the plunger, and that actually looked very good and corrosion free in my case. My switch appears to have been replaced from the original and it is currently an Otto Controls P6-24014 alternate part number in the IPC. When I called LASAR earlier this year looking for a Honeywell 1CH116-6 switch they told me that switch was no longer available, but recommended alternate part number P6-24014 (what I have now), and which in March 2024 was $1,152 new but out of stock. They also suggested using another alternate part number 1EN1S priced at $1,768 and one was available then from the Mooney factory.

Hello Skip, when you were researching the gear up limit switch did you by any chance also find an available alternate part number for the gear down limit switch? When I looked the Honeywell 1CH116-6 was no longer available and the alternate part numbers P6-24014 (Otto Controls) and Honeywell 1EN1S were very expensive ($1,152 to $1,768), but not in stock when I searched.

Confirmed! My serial number specific flight manual has no reference to an Alternator Switch, only an Alternator Circuit Breaker and separate Alternator Field Circuit Breaker; mystery solved. Sent from my iPhone using Tapatalk

My J is the Advanced Training System (ATS) version, so maybe that’s why? Just a WAG but really no idea why. Sent from my iPhone using Tapatalk

Just a circuit breaker for the alternator, not a separate switch. best - Hank