tjohns

24 ms·

301.
by tjohns 4y ago
> even slightly easier to read, especially if you're busy trying a fly an aircraft Pilots read these on the ground, as part of their weather briefing. If you're reading about the TFR for the first time while you're airborn
302.
by tjohns 4y ago
There are many different reasons a TFR can be issued, with varying levels of restrictions and penalties. Some you can fly through if you follow the right procedures, others are effectively off limits. Some you'll get your license susp
303.
by tjohns 4y ago
> there are at least some use-cases where the use-case preceded the formation of any multilateral body to coordinate usage The ITU-R was founded in 1927 (it was known as the CCIR back then). At that point, we were mostly worried about te
304.
by tjohns 4y ago
In a managed corporate environment (or heck, even with family members), asking users to reinstall the OS themselves is a big deal. Also, what about apps? Non-standard drivers? Background services? System configuration?
305.
by tjohns 4y ago
Global decisions are made by treaty, through a United Nations organization known as the ITU. Some allocations are harmonized globally. Others are divided up into one of three global regions - roughly the Americas, Europe/Africa, and As
306.
by tjohns 4y ago
Related, the FCC still maintains a network of monitoring stations around the US. Back in the day they were manned, now they're automated and remotely controlled. There's a list of monitoring stations here: https://www.m
307.
by tjohns 4y ago
Many of those devices are operating under the FCC's Part 15 rules for unlicensed transmitters, which allows them to use certain bands provided that they stay below a minimum power level (or use an inefficient antenna) and don't ca
308.
by tjohns 4y ago
Yeah, there's something very suspect about this data. Just off the top of my head, I'm quite sure there were more than 3 earthquakes with magnitude between 5.0 and 6.0 for the 80 year span between 1900 and 1980. Also, there's
309.
by tjohns 4y ago
Speaking personally, I just don't usually open Twitter or news sites while I'm at the office. It's not that I don't care. (I do.) I just read everything at a digest at the end of the day. Most news doesn't require a
310.
by tjohns 4y ago
There's a certain calm that comes from closing the news sites and social networking feeds, and just checking everything as a digest at the end of the work day. Staying informed is good, but there are relatively small number of things t
311.
by tjohns 4y ago
Absolutely. Driving up from the SF Bay to Tahoe, you'll lose cell service as you pass through the mountains - especially if you take the Highway 50 route. Drive up to Oregon, and you'll lose cell service for a long stretch roughly
312.
by tjohns 4y ago
More details: https://en.wikipedia.org/wiki/Mobile_Telephone_Service
313.
by tjohns 4y ago
Try "*****", style 3 or 9. I got it to write backwards at one point.
314.
by tjohns 4y ago
Domestic civilian and military radar is the same thing. It's (mostly) all managed by the FAA, and the military just gets a copy of the civilian radar feed as part of the Joint Surveillance System. [1] The limiting factor is geography.
315.
by tjohns 4y ago
If it's using Iridum or (more likely) Inmarsat, it would technically be ADS-C. (There is also a parallel system that allows satellites to detect existing ADS-B signals, developed by Aireon - but this is relatively new and not used glob
316.
by tjohns 4y ago
I think even this number is high. 80-90% sounds about right for the mainland US and Europe, but definitely isn't true elsewhere. Canada probably has ~50% radar coverage, and oceans have essentially 0% once you're beyond line of si
317.
by tjohns 4y ago
That number can't be right. 98% of the earth doesn't have primary radar coverage, let alone secondary (transponder) coverage. ATC radar is line of sight. At an altitude of 40,000 feet, you're beyond the radio horizon and lose
318.
by tjohns 4y ago
(Following up on this, I was actually mistaken. I believe NADIN is actually an FAA network.)
319.
by tjohns 4y ago
For what it's worth, the METAR network (NADIN) is maintained by the NWS, not the FAA.
320.
by tjohns 4y ago
The problem is that "criticality" is too binary. A tower light NOTAM might be low-criticality for a fixed-wing airplane pilot flying day VFR, but high-criticality for a helicopter pilot flying at night in IMC. Similarly, chart upd
321.
by tjohns 4y ago
A pilot can legally land without a METAR, and this happens all the time. The stations can and do go offline. Sometimes they break, especially after a severe storm. Many smaller airfields don't have on-site weather reporting, some other
322.
by tjohns 4y ago
You have it backwards, ATIS doesn't pull from METARs... the METAR and ATIS recording are both produced at the same time locally by the local weather observer (usually a controller in the tower), reading raw data directly from the on-fi
323.
by tjohns 4y ago
The 3 minute delay for wake turbulence is required by ATC procedures (when applicable). It can only be waived by the pilot in specific situations, and only by the pilots request. It's built into the procedures, expected, and is total
324.
by tjohns 4y ago
> I bet that he was not cleared for a visual departure out of DCA. Why not? DCA has a charted, named visual arrival. A visual departure via pilotage is no different, and is very common for VFR flights. (Yes, they would've been given
325.
by tjohns 4y ago
The river visual is a published approach for DCA. P-56 (the restricted airspace the pilot almost penetrated) is VERY well known and would top of mind for anyone flying in that airspace - not to mention highlighted on paper charts, EFBs, and
326.
by tjohns 4y ago
Indeed. Popular landmarks used by ATC in the SF Bay Area include a sunken ship in the middle of the bay, a (particularly large) church, a community college, an AT&T telephone office, the KNBR antenna, and major freeways. Among others. I
327.
by tjohns 4y ago
The official weather notifications (METARs/TAFs) can be displayed in more modern ways, but many pilots like the brief coded weather messages because they can be easily skimmed for an entire route of flight. In my mind, AIRMETs were a b
328.
by tjohns 4y ago
Most glitches are localized, or there's backup systems, or you can fall back to manual human processes. If pilots/dispatchers can't get current NOTAMs, the aircraft can't safely depart - especially if they're flying
329.
by tjohns 4y ago
I think the implication was more that any government meteorological office's format is the default over a small private company. Especially since this API is repackaging output from the NWS's GFS model output.
330.
by tjohns 4y ago
Those can all easily be emulated in software, if you're determined enough. There's nothing about the WebAuthn protocol that forces hardware backed key storage, other than everyone collectively agreeing it's a good idea. A bot

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