NicoN

Perhaps someone did it ... Our pilot's side sun-visor fell because the second bracket which holds the visor on this ~ 4mm steel wire broke. My first idea was to rebuidlthem from a piece of sheet-metal

To be honest, the installation of our GI275s was not "flawlessly". First, the installer could not go through the calibration process for the GMU11. We could solve this problem, but then the A/P did not react to the heading bug as expected. It turned out, that the C21 flight controller was still jumpered for using a DG, but the GI275 "talks" HSI. It was not easy to convince the installer of what ist wrong, but finally it worked. Our C21 was working absolutely fine before the GI275-move, but is still not completely fine. 1. NAV/APPR mode is always working ( a little of center, but working) 2. HDG mode is always while the A/C is in the hangar. 3. Sometimes HDG mode stops working while in flight or while taxiing. In the air, the A/C is simply flying straight and wings level, like a wing leveller not reacting on the HDG bug. 4. Sometimes the function comes back shortly after landing. 5. It seems to be related to temperature. On real hot days it did not work. Last weekend I did several flight each 2h and it worked perfect. My first suspicion was a faulty connection from GI 275 (heading error) to the C21 flight controller. I followed the signal from the connector Pin 17 to the upmost PCB (it is a stack of 3 PCBs and soldered a little cable to measure the signal. If anything works, I can measure a voltage of 0... 9,7V, depending on the position of the heading bug (max to the left is 9.7V, max right almost 0V, or vice versa). in the middle position the voltage is around 4.8V (half of 9.6V). So, exactly as you posted it. If the HDG mode stops working, I measure 4,77V on this Pin 17 and it does not change with moving the heading bug. Of course, this can be a phantom voltage which does not come from GI275, but from the flight controller itself. So, the faulty connection is not completely ruled out. I was lucky, to buy a C21 flight controller for almost nothing on ebay, which is only partially working. The C21 Flight controller has 3 stacked PCB which are folded and connected with ribbon cable. The upper 2 can be easily removed while the bottom one is together with the front panel and the housing - so i call it the "chassis" - Our flight controller was bench checked as fully working - i was not possible to "provoke" the failure with a heater in the footwell - the misbehaviour happens also if I change the upper 2 stacked PCBs to the ebay chassis. So, a problem can still be on the upper 2 PCBs @Jake@BevanAviation: Can you give me additional information about that "routing" IC? All the ICs are thru-hole chips which are availbale via digikey, but there are many chips to change. So, a lot of work. Most of the chips are 4xAND, NAND, OR, NOR chips. Still, I am not sure that the GI275 is NOT the reason. At least, I can confirm that the HSI becomes not more than handwarm. Is the PFD with ADHARS-AP running hot? I am also not sure, that the AP HEADING ERROR LO signal is connected correctly.

A couple of days ago, I was forwarded a beechtalk newsletter, where on topic is something about GI 275s and Century A/P The beechtalk.com website is not available at the moment. I was pretty electrified , that there was information about problems with GI275s an some Century A/P, e.g. the 21 model which we have. Since the GI 275 was installed we have intermittent trouble but only with the HDG-mode. Everything else is working fine (more or less). It seems that especially under high temperatures, the A/P stop reacting on changes on the heading bug. The A/C then simply flies straight on the last heading (of course starts deviating). It is a wing leveler only then. Sometimes the HDG mode comes back by opening the ventilation air. Sometimes you can kill this function by switching on cabin heat. In the failure case, I can measure a voltage of 4.77V on the heaidng error signal inside the A/P controller! The beechtalk newsletter says something to install a 1kOhm resistor to improve impedance and avoid "power fault " messages. For our C21 this is even warranty reimbursed! To be honest: I have never seen this message, but I am pretty interested to see WHERE this resistor is installed. I am afraid, the newsletter does not giv any information about that! I do not even find a SB about that, rather than an installation manual with the necessary information. Has anyone additional information ?

In the meantime my partner analysed our JPI data and is of the opinion that in September 2023 the spread increased. I think a couple of month we had 2 cylinders replaced. At least one is in the group of leanest/ richest.

Recently, my co-owner found a GAMI-spread of 1,0 ..1,2 gallons between leanest and richest cylinder 2 and 4. Our A/P cleaned the nozzles with ultrasound and MEK, but teh result is noo change. What to do in this case? Swap nozzles 2 and 4? BTW: my co-owners says not to fly LOP. Is our GAMI-Spread really too high?

Yes, I have it

Thank you! I am also of the opinion that it is not a general problem. 1. HSI can work as a PFD, I checked the auto-revert feature a couple of months ago - IAS and altitude are the same and headings is also fine 2. you can see that the msic. Field CAN indicate the winds aloft. Nevertheless there are rumours that in general the winds aloft calculation might confuse left and right Garmin was not interested in my video but recommended to find a solution with my authorized Garmin dealer. To be honest: my "authorized Garmin dealer" was not able to complete the calibration of the GMU11. They did not even have a secret contact to a Garmin guru to find the solution We are definitely not on the latest firmware (we have 2.62). Wasn't there something that the latest firmware makes my analog NAV2 (KX155) useless? I was hoping that someone says "this problem is solved with FW xyz" or a sophisticated config value

Video to demonstrate th eproblem As you can see, I have winds aloft indication on the PFD and also TAS. The problem for the HSI is also shown

Sorry, my posting was not precise. English is not my native language. And yes - we have OAT, we see as calculated TAS on PFD; that works The Misc. Field on the PFD can display winds aloft in different flavors, such as Headwind/crosswind, windspeed and a little arrow for direction and also windspeed and driection in degress. All work fine on the PFD Same can be configured on the HSI and this time the indication of valid information does not start automatically, but only afetr appling the setting again. then I see the information I want. On top, the setting seems to be volatile; with the next flight the same problem arises - definitely not a real problem but annoying.

GI275 has an option to display a "Misc. Field" in the display of a PFD and also on the HSI. one option is to display wind/velocity in different versions I configured the HSI to display wind direction and velocity. Therefore a little block appears on the display with "360/--"; sounds fine. The aircraft is on ground, so no GPS-Speed or track and also no airspeed. But, while in the air, it did not display the wanted information - still "360/--". Then - while - flying, i configured the same setting again, and voila, now it displayed a value (no clue if correct). on my next flight - same problem again, information is displayed but non-sense. And again, problem can be solved by applying the setting again. Any ideas ? is this a known problem? i did not see that this is addressed by a higher firmware (we have 2.62)

Our A/P wants to overhaul our alternator and/or the slip clutch (?) I saw once in januaray a fluctuatiing indication of our amperemeter (rapidly moving hand, but only about 10% of the meter range). This stopped after a couple of minutes and I have never seen it again.

We have this little panel with 4 fuses in the copilots foot well. One is for instrument lighting. On top there is a C/B for the same purpose. Why?

I was asked from my partner if we (also) have an additional screen filter besides the normal oil filter. The reason for the question: In a PIPER owned by his son horrible things were found in the screen filter

I started this topic a long time ago. I simply noticed that your CDT needle did not move at all A shop diagnosed the indicator as faulty, but it was never changed. Trying to find out what to do, I simply disconnected the sensor and measured the resistance: overload. Then I shortened the wires to the instrument with master switch on - full deflection. So instrument is fine. we then replaced the sensor and CDT is working since then. My experience: during takeoff, at sea level CDT was never an issue. The needle is moving a little but never critical. The higher I climb, the more CDT is rising. I saw situation where I had to lower the power as CDT was approaching the limit temperature.

Right, we also have electrical trim but not auto-trim. So, the answer is: we need THREE servos Next question: We have 2 GI275 installed; do we ONLY need Servos (3) and a mode controller, or do we need another G5 or GI275?

I Recently changed the setting for the MISC.Field on the PFD and the HSI The PFD shows now a direction arrow and wind speed. On the HSI , I configured this MISC Field to indicate Headwind/crosswind, but this shows only two lines of dashes (in the air) The previous setting was TAS and it worked. So, I think the HSI has all necessary information it needs What is worng?

A colleague said, that the GFC500 provides vertical guidance by using the servo not direct on the elevator but using the elevator trim. Therefore he has the idea that you need 2 Servos to have lateral guidance AND vertical guidance including elevator (auto)trim. I thought you need 3

Okay, mission accomplished. Even with a newer firmware, switching between HDG and GPSS mode is not perfect. Using an external switch is way better. But the necessary details are not so easy to get. Her is what I did. 1. The switch needs to be wired to the PFD (the GI275 with ADRHS and Ap interface), not the HSI; which is nice because it is the top device 1a It needs to be a switch, not a pushbutton. The swithc connects to GND in GPSS mode, HDG mode is done when teh switch is open with a pullup-resistor. You do not need an external one. 1b I suggest, install a DPDT version, just to have something ready to drive a indicator lamp; the GI 275 has AFAIk no pin to drive a indicator lamp. 2. Find a discrete-IN pin which is not in use. 2a The discrete pins are spread over the J2751 and J2752 connector. 2b I recommend preferring the J2751 connector over the other. J2751 is the upper connector and therefore easier to access. 2c in my installation the discrete-IN on pin 62 and 63 were not in use, which makes it easier. Pins 60 to 78 are located in the upmost row and pin 60 is the rightmost (easy for people like me who have problems with numbers greater five ) 3 one pin from your switch needs to be installed in location 62 or 63. 3a make sure the pin is inserted all the way (it should not be shorter than the others) 4 the other wire from your switch can be connected to the backshell from your connector or to one of the "Aircraft ground"-pins not in use. But this is way more complicated (number greater five, you know !) 5 Next start your PFD in config mode and go down to DIAGNOSTICS - DISCRETE IN 5a There you should see something happening when flipping the switch 6 NExt go to your autopilot settings (it is way down in the INTERFACES menu) and 6a select DISCRETE instead of BUTTON 6b select the appropriate DISCRETE IN pin 7 leave the menus and power down both GI 275 7a wait 30s without power 8 power up in normal mode 9 You should see your heading bug changing from full to hollow if you flip your switch 10 install the switch. 10a I recommend to install it with the plunger to the left ( to the PFD) indicating HDG mode on and right (to the GNS430 or so) indicating GPSS. Have fun; maybe someone finds that helpful A word to the HD-pins for the 78 pin D-SUB: I was not able to find the turned pins which need this crazy expensive crimping tool. Instead, I found only those stamped ones . They can be crimped with the cheap crimping tools offering an option fro D-Sub. But it takes a good portion of experience before you make acceptable pins which can be inserted correctly. So, under all circumstances, use the turned ones!!!!

Oh yes! GI 275 and GNS430W are playing in a team. This works already. At the moment we are using the touch button on the PFD to switch between HDG mode and GPSS. But you can also put this function to an external switch.

Thank you. My posting was not precise enough. The "pull to ground" is a typical feature of all microcontrollers. INternal pullup drwas the pin to "high". If you short it to GND - fine. Both Gi 275 have some free Discrete IN- pins free for use. So, the question is - on which device do I use/wire the switch? On the PFD? Or on the HSI?

I want to have the external switch to toggle between GPSS and HDG. I found all options hpw to configure. For me the question is: On which device do I have to connect the switch to one of the Discrete inputs? PFD ? sounds logic as the toggling happens here and the PFD has the AP interface I think it is a switch between Discrete in and GND

We have a M20k with the trim switch in the left yoke horn. Also there is the MIC-Button, trim interrupt switch and we want a AP-disconnect switch. I am looking for a littel box to assemble on top to have more space for all the switches. Is there a 3D CAD model available or a pre-frabricated box? Google is PITA if you do not have the correct words to serach for

No. We still have the same problem. The GI 275s seems to work perfect - no error messages, no aligning. The heading/compass is stable and super precise, but the calibration was another nightmare with our installer. Finally we did it on our own. Last weekend I had 2 flights in F120 for 4 hours - and believe it or not: HDG mode was perfectly working at cruise altitude and failed again in low altitudes. I tested it several times and HDG mode was working with manual HDG changes and also with GPSS activated. When it was working I reached under the panel and the tray was really cold. So, maybe we have a temperature problem. I quickly made an extension cable to operate the computer off the tray, but did not try it in real life so far. Another question: has someone a schematic of the boards inside the computer available? I have the service manual but this ends always with "replace unit". For me, the upmost board drives the heading function, the middle seems to be responsible for NAV mode and the lower seems to have some power supply function and the power transistors for the motor.

I joined a Ownership for a 1980 M20K in 2018; right after all 6 cylinders had been replaced. Analyzing the old logs from our EDM830 clearly showed, that the aircraft was flown often hot if not too hot with CHT over 400°F for a longer period of time. We came along to fly LOP to save the engine's life forever. Since then we are donig this; flying LOP with 58-65% power and CHTs never over 390; in cruis we have TITs of ~1535 and FF 8.8-9.2 gals. GAMI spread is also fine Now, again 2 cyl are with low compression. Even though the exxhaust valves are looking fine. The cylsa are loosing pressure via the valves and also into the crankcase. In-place-lapping improved one cyl and had no impact on the second. Now, the shop says, our problmes are caused by flying LOP!! and he sees those problems more and more often as people flying LOP and especially in TC Mooneys and Cirrus. Okay, what to do? If Mike Busch is right propagating LOP with lower CHTs then we made everything accordingly. But if not?

That looks exactly like ours when it broke