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Satellites Could Show Airplanes Faster Long-Haul Routes in Mid-Air (qz.com)
The promise of powerful satellite constellations orbiting hundreds of miles above the earth can seem, well, a little distant. But what if they could make long-haul flights faster? From a report:
Operators like Iridium and Inmarsat are promising that jet liners linked to space communications networks can save fliers money, time and carbon impact, as more efficient flights cut fuel use. Today, an airliner flying five miles over the open ocean, beyond the reach of the radar systems used by civil air controllers, is dependent on flight plans written well before take-off, and what pilots could report over the radio to scattered air traffic controllers. Weather bulletins still arrive in the cockpit as brief text messages. But a true global communications network -- one orbit around the earth -- could give pilots the flexibility to react to changing situations in real time, the same way Google Maps now allows drivers to re-route around traffic jams as they drive.
right now we can lose aircraft over sea and not even know which direction they went.
at least this way we'll be able to pick up body parts
I think the whole point is adjusting for weather conditions. They want to optimize flights to avoid turbulence and maximize tailwinds. The assertion in the summary is that pilots don't have enough information to do a good job on that right now (at least when flying over the ocean). I wouldn't be surprised if you could average a 15-minute improvement over the Atlantic and double that over the Pacific, which would translate into a lot of fuel savings for the airlines.
Flights over the Atlantic are coordinated between Canada and the UK. There is a set of 10 "routes" each way and the air traffic agency responsible (Canada for east to west, UK for west to east) sets up the routes (which vary daily) and the scheduling of aircraft on the routes.
This is done so while aircraft are over the middle of the Atlantic where there is no radar coverage, they won't encounter traffic - either because they're running into slower traffic ahead, traffic going the other way, or traffic beside them.
It's not the most efficient, but it's the safest route - and very little deviation is allowed.
And yes, there are traffic jams, which is why there are 10 different "lanes" going both ways.
The thing is, ADS-B (yes, ADS-B) is being implemented worldwide. Unlike the US system though, most countries are going with a space-based satellite system, so your ADS-B transponder will talk to the satellites. (The US went with ground based systems because there is so much airplane traffic that it would overload the satellites). With this it means the location of all aircraft will be known, so it will be possible to control aircraft beyond radar coverage (just because they are beyond radar coverage doesn't mean they are beyond radio range - satellite messaging and HF radio allow all aircraft to still be in communication).
That is because of airplane departure time. If you push back on-time, then it was an on-time departure. Doesn't matter if you sit there for 3 hours before you finally take off - the departure was on-time because the definition of departure time is when you push back.
Browsing at +1 - no ACs, I ignore their posts. So refreshing!
and observing vertical separation minima distance it's a very deep stack of lanes too
The article is a bit unclear because it is a sales pitch aimed at a very small market.
What they are mainly talking about is airspace separation. In controlled airspace air traffic controllers maintain a significant buffer around each aircraft to ensure that they don't get too close and 'overlap'. The size of the buffer is significantly impacted by the accuracy of the monitoring, if you want a 5km gap and you know the location of aircraft within 5km you need a 15km gap.
There are a whole bunch of technologies used but the fallback is waypointing. The aircraft reports that it is at waypoint A proceeding to waypoint B at 600knots. You then can then predict where the aircraft is but accuracy is terrible, consequently the separation required is huge.
ADS-B is a new surveillance technology (2004) where each aircraft broadcasts its position every second. Ground stations can then pick up this broadcast and feed it to the air traffic controllers. It is significantly cheaper and covers a much larger footprint than a secondary radar system.
Aireon is monitoring the ADS-B signals from low orbit communication satellites and providing a feed of that data to air traffic controllers. This solves the obvious difficulties of installing ground monitoring stations in the middle of the ocean. It may also significantly boost worldwide adoption by avoiding the need to install ground stations at all.