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JMCT

@jmct.bsky.social
1.1K followers 199 following 366 posts

Director of The Haskell Foundation, former lecturer UMD CS. Jazz, music theory, compilers, privacy and aviation, sometimes I combine them. I can also be found @jmct@types.pl I miss Yorkshire

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JMCT @jmct.bsky.social · 05/10/2026
Beautiful profile of some lake effect weather at YYZ today! #avgeek
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JMCT @jmct.bsky.social · 20/09/2026
Great photos! I hope Ottawa/Gatineau treated you well!
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JMCT @jmct.bsky.social · 11/09/2026
And of course, there’s a belt there again
Photo of the alternator with an alternator belt
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JMCT @jmct.bsky.social · 11/09/2026
Here’s the before and after of me turning on the avionics, with the engine off, to test the new alert. It works!
EIS engage mode showing that there are 0 A flowing to the battery and there is no alertEIS engage mode showing there are -2 A flowing to the battery and there is an alert
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JMCT @jmct.bsky.social · 11/09/2026
For those that wanted to know the conclusion: New battery is installed. I booted up the SIS and you’ll see that there was no low amp alert set, and now there is! I still need to improve my scan, but the point of technology like this is to help, so… now it’ll help!
EIS showing that there is no alert for battery amps
EIS showing there is now an alert for battery amps
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JMCT @jmct.bsky.social · 05/09/2026
Haha no, that would be even spookier. It got caught on something inside the cowling. We didn’t see it last night but I went back today to look for it. I’m very glad it didn’t fall out through the cowl flaps as it is helpful in diagnosing.
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JMCT @jmct.bsky.social · 05/09/2026
Also did some logbook spelunking. It’s not a smoking gun but in 2024 the battery needed a ground charge. So even two years ago it was showing signs of not holding a charge.
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JMCT @jmct.bsky.social · 05/09/2026
The symptoms don’t _perfectly align_, but signs are currently pointing to a belt failure and not an issue with the alternator. We’ll have to check alignment between the pulleys, but it may have just been the belt’s time to go.
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JMCT @jmct.bsky.social · 05/09/2026
Found it:
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JMCT @jmct.bsky.social · 04/09/2026
When we lost radios, she immediately reached for the handheld where I had told her it would be, plugged in, and took over comms. After she was set up with the radio, I signaled her to take controls and I started the gear down procedure.
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JMCT @jmct.bsky.social · 04/09/2026
I’m frustrated with myself that I didn’t catch the alternator failure sooner, but I’m happy that I had briefed the rated-pilot passenger what we would do if we lost radios, how emergency gear extension works, and who would do what.
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JMCT @jmct.bsky.social · 04/09/2026
I always fly with a handheld aviation radio that you can plug your headset into. Never used it in flight h til yesterday! Prevented me from going NORDO and enabled us to coordinate a flyby of an airport that was open to ensure that my hand pumping of the landing gear was successful.
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JMCT @jmct.bsky.social · 04/09/2026
Yeah, one lesson here is at the ammeter needs to be a more consistent part of my scan. And once I get a new battery, I need to configure the EIS to have sensible warnings. I shouldn’t have assumed it would shout at me.
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JMCT @jmct.bsky.social · 04/09/2026
Yeah, I didn’t do any load shedding, because I didn’t realize about the alternator failure. Turns out that the EIS I have does not come configured to warn about that by default(?!) And the battery was pretty old Lots for me to learn from this
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JMCT @jmct.bsky.social · 04/09/2026
Oh, battery didn’t last long… all electrical equipment failed. There’s more diagnosing to do, I think I might need a new alternator and a new battery. I’m hoping that’s the end of the list :)
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JMCT @jmct.bsky.social · 04/09/2026
Absolutely gorgeous flight up until the alternator failure
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JMCT @jmct.bsky.social · 04/09/2026
When I took off, there was a belt there.
Alternator without an alternator belt 
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JMCT @jmct.bsky.social · 03/09/2026
And that’ll sit in the little stencil follower arm thing?
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JMCT @jmct.bsky.social · 02/09/2026
I used to use that but it’s missing mobile support (last I checked, at least) and options for cloud DB support. One of the benefits of Signal being a foundation, and not only an Open Source project, is that there’s an entity that has the funds and infra to run that sort of thing.
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JMCT @jmct.bsky.social · 02/09/2026
Signal : WhatsApp :: ? : 1Password/LastPass/BitWarden Who wants to start a foundation to fill the ? with me?
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JMCT @jmct.bsky.social · 02/09/2026
Wait, where can I get that?!
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JMCT @jmct.bsky.social · 02/09/2026
Turns out that using these things is a skill
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Reposted by JMCT
ionchy @ionchy.ca · 23/05/2026
start doing computer science <3
START DOING COMPUTER SCIENCE

* VARIABLES WERE SUPPOSED TO BE GIVEN NAMES
* YEARS OF PROGRAMMING yet STILL MORE TO CREATE
* Don't want to write code anyway? We have a field for you: It's called THEORY
* "Well typed programs don't go wrong." "Boolean satisfiability is NP-complete." "Every effectively calculable function is computable." — Statements dreamed up by the utterly inspired

LOOK at what computer scientists deserve your Respect for all this time, with all the circuits and computers we built for them
(This is REAL computer science, done by REAL computer scientists):

[graph of the ARPANET] the Internet
[photo of an FPGA] FPGAs
[screenshot of RocqIDE] proof assistants

They have given us beautiful tools
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JMCT @jmct.bsky.social · 16/08/2026
Hell yeah
Air traffic control is the latest occupation to be womanized
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JMCT @jmct.bsky.social · 09/08/2026
Needless to say, these two differences basically make it kind of the opposite of what we were taught to expect in the US and so I really fucked up everyone’s plan
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JMCT @jmct.bsky.social · 09/08/2026
That said, they do not like 45° entries into the down wind. Also, they are approaching the fields from the same side as the pattern, they will overfly the field above pattern altitude, then turn around and cross the field at pattern altitude to join the downwind directly
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JMCT @jmct.bsky.social · 09/08/2026
OK, so I want to be very clear here: Not only are there differences in pattern entry, but I made some assumptions that I should’ve never made even if I were flying in the US. I was just basing what I did off of one of the airports I frequented that _I thought_ was similar. So… mea culpa all around.
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JMCT @jmct.bsky.social · 09/08/2026
I made a mess of the pattern and pissed off some folks (and apologized on the ground, of course). Pattern entries are not the same in Canada, I knew that, but didn’t know the extent of the differences! But at least my landing was good. It’s like landing a shopping cart.
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JMCT @jmct.bsky.social · 09/08/2026
Can someone with Foreflight see if they’re able to get surface analysis on the map layer? I know I can use the imagery tab for the old-school surface analysis, but I am curious as to why I’m only getting “no data” when I try to add the surface analysis layer.
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JMCT @jmct.bsky.social · 08/08/2026
Nine? Nine… eleven… Coincidence?!
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JMCT @jmct.bsky.social · 07/08/2026
Increase in the rate of things happening.
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JMCT @jmct.bsky.social · 04/08/2026
Things are happening
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JMCT @jmct.bsky.social · 01/08/2026
I guess the adventure cat lessons will have to wait for another day
Cat sleeping in box. Book on adventure cats in foreground.
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JMCT @jmct.bsky.social · 29/07/2026
During Oshkosh and Appleton is a very common Oshkosh overflow. Could be unrelated! But interesting timing.
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JMCT @jmct.bsky.social · 24/07/2026
Folks, I’m at the Operation Airdrop booth again this morning. Come say hi! #osh26
Photo of a tent at airventure in Oshkosh, Wisconsin
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JMCT @jmct.bsky.social · 22/07/2026
Also, if you have any social media presence… come and post about it and help spread the word!
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JMCT @jmct.bsky.social · 22/07/2026
I made a post about my piloting experience for them a few years ago: jmct.cc/opairdrop/
jmct.cc
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JMCT @jmct.bsky.social · 22/07/2026
Oshkosh folks, come to the Operation Airdop tent (co-located with the Legend Cub tent) and talk to me about volunteering! #osh26
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JMCT @jmct.bsky.social · 21/07/2026
Anyone wanna hunt some U-Boats?
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JMCT @jmct.bsky.social · 20/07/2026
The “unwritten rules” in a section titled “requirements” is hilarious to me. It would be a good bit if it weren’t gross.
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JMCT @jmct.bsky.social · 20/07/2026
@peacewind.aero which one did you fly in? I’m officially team 017
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JMCT @jmct.bsky.social · 20/07/2026
It’s happening!
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JMCT @jmct.bsky.social · 19/07/2026
I’ll be at Oshkosh all week, mostly volunteering at Operation Airdrop and the Seaplane base. Anyone around? #OSH26
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JMCT @jmct.bsky.social · 18/07/2026
Results
Latte in foreground. Lake in background.
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JMCT @jmct.bsky.social · 18/07/2026
Improvisations.
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JMCT @jmct.bsky.social · 05/07/2026
View from the woods last night.
Sunset over a lake. My shoes in the foreground.
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JMCT @jmct.bsky.social · 03/07/2026
Worst thing that ever happened to me was learning about type systems.
"Color: 15", "Size: Black"
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JMCT @jmct.bsky.social · 28/06/2026
Ah damn, well, apologies for the mistaken identity. I hope you had a good flight, though!
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JMCT @jmct.bsky.social · 28/06/2026
Maine is pretty
Shot of a river flowing through a forest in Maine. Taken from the pilot side of a light high wing Aircraft.
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JMCT @jmct.bsky.social · 28/06/2026
Peaceful to bumpy pretty quick
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