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Comment by billziss | Hacker News Reader

I am no fighter pilot, but I (used to) fly airplanes, floatplanes and helicopters. A watch with a 12 day battery life makes little sense to me as I find it too easy to forget to charge it. Even if you put it on a checklist, it may be too late to charge it when you are about to go.

For my flights I mostly use an automatic Glycine 24hr watch with a second dial set on UTC for "Zulu" time. If the watch is running at the beginning of the flight (confirmed with a checklist) it will continue running during the flight.

I have to admit that this Garmin MARQ looks lovely though :)

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These watches don't have anywhere near 12 day life with the GPS enabled. Depending on the watch and the temperature it is anywhere from 2 to 30 hours.

Good catch!

From the Garmin MARQ Aviator page:

> Smartwatch mode: Up to 12 days > GPS mode: Up to 28 hours > GPS with Music: Up to 9 hours > UltraTrac™ mode: Up to 48 hours

Almost any GNSS receiver is by design power hungry. Modern mostly SDR constructions have faster time to (reasonable) fix, but still it involves large amounts of essentially opportunistic computantion to acquire and track the CDMA downlinks. This is one of the arguments why Spy-Fi style inconspicuous and globally accurate and useful trackers are nonsense. The whole process of associating with 2G GSM network and sending one MO-SM message is incredibly energy expensive, but getting reasonable GNSS fix is in completely different barpark.

Possibly more feasible if you periodically capture and store a few ms raw IQ, then transfer a quick burst when the handler comes near, to do the nav solution offline.

Yep, there are a number of offline ways to solve for position. It needs 200-500mS of GNSS signal.

I like the Yabby: https://www.digitalmatter.com/Devices/Lorawan-Trackers/Yabby...

Also: http://chipfox.cz/

I fly sport planes and the battery in the iPad I use to augment the cockpit has a 5 hour life. I definitely have the "charged iPad" on the checklist, I don't make assumptions and I make sure to charge it before flight. I use it for GPS altitude only as I have 2 baro altimeters and an old Garmin GPS, but the iPad's GPS is usually more precise to indicate current height above ground. A 12 day battery life for a smartwatch I would only wear when flying is more than enough. I would not wear the smart watch on the ground, my regular watch is running without any maintenance for 21 years (Citizen EcoDrive).

I think this likely has to do more with individual habits rather than anything else. But I find that watches that I do not use all the time are more likely not to be ready to be used when I need them.

For example, I have an old Suunto Ambit watch that I used for outdoor activities and/or exercise. I found that because I was not wearing it all the time, it was not charged most of the time that I needed it.

I put my GPS watch on the charger and forget about it when I'm not using it.

Probably a silly question, but why can't you charge the iPad in flight? Surely planes have some sort of socket like cars?

>Surely planes have some sort of socket like cars?

Unfortunately no, and often it’s not trivial to legally install one.

If you can install an iPad surely it wouldn't be too difficult to also install a battery pack to boost the battery life if nothing else.

That's fair, but you'll still need to keep the battery pack charged :)

Can you put a little solar panel instead? :D

Pretty sure you can, but you’ll have to use tape and not screws to hold it in place so it won’t be a permanent installation :)

But yeah, go experimental and then you never have to worry about these things. Lots of great value kit planes out there.

The issue is certified aircraft. I think the 'certified' USB charger was around $300 for the part when we installed one - in addition to the certified mechanics time. The experimental side is cheap.

The Tecnam P2008 has a 12v socket and it's a rare luxury in an otherwise awful plane. Most single engine piston aircraft don't have charging ports or 12v sockets.

I had one in my '67 182 and two in each of the 58P and then A36 that replaced it. I seem to recall them being present even in the Piper rental airplanes as well.

The point was to compare battery life and care for equipment. I cannot mod the plane to add a 12V socket, but I can use an external battery pack. Still, 5 hours vs several days comparison still makes the smart watch good enough.

Or a nice 20-30mAh portable battery? Those charge my iPad Pro like 5x.

I think you meant Ah instead of mAh, or 20000 mAh instead of 20.

Curious why you think planes surely have outlets in them?

We're not talking about jetliners here. We could easily be talking about planes that are suitable for clear conditions only.

My light plane has six 2.1A USB ports for charging use plus several others dedicated to avionics updates that can also charge. In addition I have three 24V cigarette lighter "outlets" which have two dual port USB adapters. So... Plenty of on board charging foe the six seats. Not hard to retrofit. I only wish I had more!

What's the plane and did it come with these or did you or someone else add them?

It's trivial to have such things for your plane (talking about small planes with propellers etc used for hobby flying, commercial aviation of course would have specific requirements) -- it's getting them to pass the relevant regulations that's the deal. Eg.

https://www.aircraftspruce.com/menus/ps/ipad_usb.html

That sound less like a plane and more like a flying USB hub. :)

I know very little about planes and think of them as being very like cars, and a 12v socket is a cheap and useful feature in practically every car since the 1950s (more recently USB has replaced them) so I assumed planes might have the same thing.

I would expect them because I would have expected that back in the '50s and '60s people would have started using their plane's cigarette lighter socket for powering things, just like they did with cars, and so people got used to having power available and thus manufacturers would keep including it even when cigarette lighters were no longer standard equipment.

And yes, small planes used to have cigarette lighters.

There's an airworthiness directive from 1979 that required owners of a bunch of Cessna models to either disable the cigarette lighter or add a circuit protection device. There's a copy of that AD here [1]. It includes a big list of Cessna models and serial number ranges, which can give a good idea of how common cigarette lighters were.

[1] http://www.cessna172club.com/forum/ubbthreads.php?ubb=showfl...

My C182 had a 24v cigarette lighter plug that was there when the plane came to me and I think was from the factory. Took a while to find a 24V USB charging dongle, but when I did it powered my iPad just fine.

Well, I've been to small Chessnas that did have...

Why can't you charge the iPad in the plane?

No 12V socket, too complicate the bureaucracy to add one.

See FAR 1.1. It's (correctly) judged to be a minor alteration in the eyes of most A&Ps and can therefore be signed off by just an A&P with just a logbook entry.

https://www.savvyaviation.com/wp-content/uploads/articles_ea...

> I have 2 baro altimeters and an old Garmin GPS, but the iPad's GPS is usually more precise to indicate current height above ground

I had a boss who was a pilot, and he told me this riddle:

Q: How do you measure altitude with a barometer?

A: Drop it and see how long it takes to hit the ground.

>I fly sport planes and the battery in the iPad I use to augment the cockpit has a 5 hour life.

You could trivially get a smaller than the iPad power bank with you and get up to days worth of battery life...

They are functional, durable, and extremely common in my office of Learjet and King Air pilots. I agree with you on the battery life. Personally I'd rather have some world-timer, but I'm an asshole.

There's a reason why second timezone watches are called "GMT": the original one (Rolex GMT-Master) was designed in partnership with Pan-Am Airlines:

* https://www.bobswatches.com/rolex-blog/watch-review/everyone...

If you're wearing the watch on a daily basis then the battery gauge on the face makes it obvious when you need to recharge. You can fully charge the battery in the time it takes to shower and dress in the morning. And if you're only wearing it for flights then just leave it connected to the charger at other times.

>I am no fighter pilot, but I (used to) fly airplanes, floatplanes and helicopters. A watch with a 12 day battery life makes little sense to me as I find it too easy to forget to charge it. Even if you put it on a checklist, it may be too late to charge it when you are about to go.

Whereas a watch with a 24hr battery makes more sense?

I'd say, if you're to forget it, you are to forget it, whether it holds a 24h or 12 days...

And if you're doing an emergency landing and/or you're stranded somewhere, you'll want to have that 12 day watch with you, not the 24h one...

I have a Garmin Fenix watch and the long battery life is why I chose it - it's much better than most smart watches. I charge it every week and have over 50% battery life by the next week.

Maybe a stretch to equip F18/As with a USB plug, but could make sense in airplanes, floatplane and helicopters.

That does look like a 21st century fliegeruhr. Looks nice. One wouldn’t think a ‘watch’ would still prove useful for flight, but obviously the durability and modern features make this watch indispensable in flight emergencies.

Agree. The Garmin MARQ Aviator is beautiful. They just need to make a solar version that does not require charging and then I am a buyer.

There is a solar version of the Fenix 6 (the slightly less ridiculously priced sportswatch brother of the MARQ series), and according to most reviews, it barely makes a dent on battery life. I wouldn't hold my breath for self-sufficiency.

Hello could you please explain what's the added value of the 24h face? I looked at some pics and feels too crumped; however I understand that it's preferred among pilots.

Thank you

Zulu time where I mostly fly is 8 hours off local time. If the watch is a regular 12 hour watch you have to do a mental calculation for time and as a pilot you learn that the less mental calculations the better, when a lot of things are happening in the cockpit.

It is true that the 24 hour display is cramped. But I got used to it after 15 years with this watch.

I cannot find the exact version that I have online, but this one is the closest:

https://www.jomashop.com/media/catalog/product/g/l/glycine-a...

I have mine on a nato strap.

What information are you receiving during flight that is in Zulu time? Are all communications done in Zulu time?

Yup. Weather, flight planning, most of the interaction with https://www.aviationweather.gov/

I think the watch you linked is the Glycine Airman GMT. I believe the standard hour hand actually has a 12-hour sweep (yes, even though the labels are both 24-hour) and only the GMT hand (pointing to the 10) has a 24-hour sweep.

From what you've described, you probably have the Glycine Airman Purist [1]. There is no GMT hand but the regular hour hand has a 24-hour sweep (and you can set the second hour dial).

(I also have a Purist.)

[1] https://www.jomashop.com/glycine-watch-gl0134.html

I was curious, so I dug out the watch. It is a Glycine Airman 2000. See here for a review from 1999:

https://www.timezone.com/2002/09/17/the-glycine-airman-2000-...

EDIT: A couple of differences from the watch presented in the article:

- My watch has a transparent back.

- My watch is 42mm and not 40mm (I may be wrong on this last one).

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