Tosten PTT switch replaced

The push to talk switch still worked but was requiring a bit more deliberate squeeze to transmit.  Probably the victim of abuse from of an occasionally white knuckled test pilot.  

The pilot's control stick was pulled apart to access the push to talk switch.   Tosten had mailed me instructions and a replacement circuit board with two switches on it.   Unfortunately, after popping the stick apart it was found that the circuit board didn't match my model, but the switches on the circuit boards were very similar.

The old button was unsoldered.   One of the good switches was unsoldered from the new board and replaced the old switch, then contacts were checked to ensure operation wasn't affected after being soldered back.

Reassembly is a bit of a challenge because the PTT trigger spring easily comes loose if the trigger moves when the switch halves are mated back together.  There were multiple lengths of screws holding the stick halves together so I made a mental note which ones went where and managed to get them back where they belonged.

The stick was reinstalled then tested.  

New charts were out so the memory cards were updated.

Buzzing around PK Lake

 

A filter capacitor helped reduce but not completely eliminate alternator whine audible on the GoPro videos.  CHT's are very close between pairs of cylinders but still vary quite a bit between the front and back cylinders depending on airspeed.  The old GoPro battery doesn't last very long so needs retired.

Take off from T67

PK Lake

Alternator whine

 My ARINC 429 module went off line again recently.   I'd made a few changes but became suspicious that dirty power is the culprit.   For some reason, I'd never put a filter cap on the alternator.  Last night I pulled up one of my videos on my iPad and the alternator whine was very audible.  On a few others, noise from the trim motors can be heard.  It didn't seem to be very noticeable when I watch it on a desktop and think it's because I don't turn the volume up very much on my PC.  Some of the videos are recorded with an audio cable connected to the copilot's receive audio and others are recorded using the GoPro's mic.   Also, I'm not hearing alternator whine in my headsets.  

The commercially available filter cap is 15 microfarads and connects directly to the B lead on the alternator.   I pulled some caps out of a PC power supply that were 470 uF and will try one of those connected at the engine buss fuse panel (which is much closer to the avionics).  

Update-flight and video seem to indicate the whine is reduced but pitch trim motor noise is still audible.  The ARINC module stayed on line.  CHT temps are

Dynon Electric Landing Gear configuration

My gear and canopy warning indications are through Dynon's EMS220 which give indications on the panel and audible warnings through the audio panel.  For the landing gear, I made a voltage divider circuit out of resistors and connected it to the yellow wire going to the landing gear switch, the other side of the voltage divider connects to ground and the middle wire goes to the EMS220 contact.  The voltage divider reduces 12 volts to less than 5 which is what the EMS220 contact I used is rated for. 

Functionally, the "Check Gear" and "Gear Overspeed" audible warnings work well with the caveat that it takes about 20 seconds for the gear to fully extend, so getting the "Check Gear" on final may require a go around if there's inadequate time to extend the gear.

The canopy warning uses a magnetic door reed switch and the latch lever as contacts to complete the circuit.  A file was created and loaded into the Dynon HDX that only warns audibly about the canopy if the RPM goes over 1900 RPM while the canopy not latched.

A quick video of the HDX setup for several widgets:

https://youtu.be/PRun_iBb4Hc

Here's an excerpt regarding the landing gear configuration from the Dynon Forum:

https://forum.flydynon.com/threads/landing-gear-up-warning.5098/

Make sure you're looking at the latest version of the manual. Here's the relevant excerpt from those pages:

Contacts Used for Retractable / Amphibious Landing Gear and Related Alerts
The simplest method to monitor landing gear state is to use a contact as there are only two states to monitor and it is mechanically and electrically easiest to install. To enable audio alerts related to landing gear status, the contact used for monitoring the status of landing gear must be named GEAR:
SETUP MENU > EMS SETUP > SENSOR INPUT MAPPING > C37 Pxx >
> FUNCTION: CONTACT
> SENSOR: CONTACT
> NAME: GEAR
To configure the GEAR contact alert for retractable landing gear:
Install the GEAR contact that when the landing gear is up, the state of the contact is UP and when the landing gear is down, the state of the contact is DOWN.
• SETUP MENU > AIRCRAFT INFORMATION:
> LANDING GEAR TYPE: RETRACT
> LANDING GEAR CHECK SPEED: (set as appropriate for your plane)
> LANDING GEAR OVERSPEED: (set as appropriate for your plane)
To configure the GEAR contact alert for amphibious landing gear:
• Install the GEAR contact that when the amphibious landing gear is configured for landing on water, the state of the contact is WATR and when the amphibious landing gear is configured for landing on land, the state of the contact is LAND.
• SETUP MENU > AIRCRAFT INFORMATION:
> LANDING GEAR TYPE: AMPHIB
> LANDING GEAR CHECK SPEED: (set as appropriate for your plane)
> LANDING GEAR OVERSPEED: (set as appropriate for your plane)
• SETUP MENU > SYSTEM SETUP > AUDIO SETUP > LANDING GEAR > VOICE


As for the actual annunciations, those are in the pilot's guide. Here's what you'll hear for each:

“Check Gear” : The aircraft is configured as a
Retractable gear, and the Landing
Gear is UP, and the aircraft is
descending through the configured
minimum warning speed.

“Gear Overspeed” :
The aircraft is configured as either a
retractable or amphibious gear, the
landing gear is not UP, and the
airspeed is exceeding the configured
maximum gear down speed.

Vance Visits-Ardmore trip-squawks

 

Vance Atkinson came out to get a stack of aviation magazines I had saved for him and to get a long overdue flight in the Cozy.  

I pulled the 50 lbs. of  ballast out of the nose and dug out an old ANR headset, and adjusted seat foam.

We loaded up and headed North.  Vance took the controls and checked the stall speed, stick/pitch force etc.  He admired the panel and avionics capability.  He gave the controls back.  I zig zagged around Class B space, climbed to 5500 and headed direct to KADM Ardmore OK.   Unfortunately, my ARINC module had gone off line and I was seeing some other Dynon messages.   It's seeming to me like the transponder's RF is causing problems since one of the recent changes I made was to pull some shielding foil off the annular slot antenna.  I'll check electrical connections again to be sure nothing has loosened up again.   The tower cleared us to land on 17 but I had a brain fart when I saw a Cherokee doing a low approach on 13 and followed it.  Oops.   Tower called me and asked if I was on 13 and then gave taxi directions to the ramp.  5 of my neighbors had also flown up to Ardmore for lunch.  

Went WOT/Rich for a bit.  More work to do tweaking CHT's.  Probably need something that is adjustable in flight.

Vance noted that he couldn't hear my transmit audio when I talked on the radio.  I think the headset was set for mono and not stereo so will check that.  He could hear fine when we were talking on the intercom.  

I noticed that the belly brake switch had been flipped accidentally in flight, but fortunately the WOT switch on the throttle had latched the relay to keep the brake up.   I've had two pilots ride with me that bumped switches on the console so need to finish the switch protector before someone breaks a switch inadvertently.  I hadn't put the "protector" on because it isn't pretty, but for now it will be more prudent to install it.

The engine did start nicely although it had to crank a bit longer after the last SDS map tweak so maybe needs a touch more fuel on the start cycle table.

Vance approves!

Test flight - CHT balancing - VOR approach - Oscar Pattern

The SDS Fuel values were tweaked to remedy a rough idling after start issue and seemed to help.  Apparently my version 3 values were to rich for the cooler engine temps below 90F. 

Despite adding some deflectors to the lower cowl ramps, #1 is still the coolest.  I think I'm going to make something more adjustable and remove the deflectors.  I might try to see if there's a way to use a servo to adjust the ramp lips in flight.  Then find an optimal position and semi-permanently fix them there.  

I did a test flight from T67 to MWL via MQP (VOR to 31).   Everything seemed to work except for the VNAV/ILS.  As far as I can tell, the Dynon settings appear to be correct but I'll consult with a friend and adjust if necessary, then test again.  The nice thing is it did follow the approach.   Unfortunately, the pattern and RNAV approach was busy so left the area to the North.

I did about 75% of an Oscar pattern, and got disoriented but did a total of 3 360 turns/climbs and descents.  I spotted a tower nearby as I was descending so terminated the practice.  The radio traffic at Mineral Wells was still busy, so headed back to T67 rather than try another approach.

Oil Analysis Lab tests ordered/Google cloud loses user data

 I've saved samples from oil changes but hadn't had them tested yet.   Another Cozy flier had chatted with me said that he's seeing ferrous metal in his last sample.  He prepaid for 6 tests and gave me a copy of his reports.  His recent oil change included his trip to Oshkosh/wet weather, so maybe the next sample will be clear.

When I change oil, I cut the filter open and look at it in the sunlight.  Recently I'd read where another way to check for ferrous metal was to rinse the pleats out with solvent, then use a magnet to pick up metal out of the solvent so I tried that this time.  There was just a tiny amount on the magnet.   I'd been helping a friend inspect his filters on a zero time 540 and had seen the first three or so filters have glitter sized specs of metal in them and after that just pieces of carbon and once it looked like a shaving of plastic from an oil bottle.

This morning I ordered the six pack lab test package from Blackstone-labs.  I've got samples from the last four oil changes to send in.

I'd been making log entries on Google Docs with separate documents for the airframe, engine and prop but not been keeping up as well with the physical hard copy logs.  I was wondering if it was worth the time to keep hard copies up to date anymore but this week, there was a tech article disclosing that Google had "lost" users data and had to do a restore dating back to earlier 2023.  I like having access on line.   I was in Houston when Dynon announced a safety of flight issue for the Autopilot Button module with specific serial numbers.  Having that info recorded in a log book in my shop wasn't as helpful as having access to it via the Internet.  It wasn't hard to boot the system up and read the serial number from the screen either. 

Weird....I found this entry and it says, "Published 12/3/23 9:31 AM" but it doesn't seem to be.....I'll hit the publish button again....

Balancemasters and other tweaks test flight

 Audibly, I couldn't tell much difference after putting on the balancer.  However, feeling the instrument panel definitely felt like the vibration was reduced.   Any rattling sound I'm hearing is resulting from the prop, cowl & turbulence apparently.  I did see 2750 RPM before pulling the power back after taking off.  TAS briefly showed over 180 KTAS.  

The "squealer" circuit I put in to remind me to turn off the buss switch didn't activate when getting back to the hangar.  Apparently the voltage on a fully charged battery wasn't low enough for the circuit to trigger.  Looks like there's more work to do on this.  I  think I'd like a way to either temporarily silence the alarm, or improve the logic.

When I was fueling at XBP, a N16KF C150 pulled up.  Out climbed the DPE that gave me my PPL check ride ten years ago!  We chatted about what I'd been doing since then and he admired my Cozy.  He was happy and confided that so many people that got their check rides "hadn't done anything".  

Back at the hangar, I pulled the cowls off in order to change the oil.  I disconnect the lower oil line from the cooler, made a channel out of foil and drain the oil into the oil filler tube.  I've had a few people tell me that the oil drains back into the engine, but I'm getting quite a bit out of the cooler and Vance did this as well.  I drilled a couple holes in the oil filter and blew compressed air in to help the oil drain out of the filter before removing it.  I've had mixed luck doing this so will see tomorrow if the oil drained out.  -Update - there wasn't any oil mess from the oil filter.  Not sure if letting it set overnight or drilling holes in both the bottom and the side were the trick, but anyway, was nice not to have a mess.

Foil guides oil draining out of the cooler and line into the dip stick tube.