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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.
Two satellite communication companies tell us that satellites communications are good. Send money now.
This sounds a lot like the same sales pitch which was being made to explain the purpose of In Trail Procedures (https://www.faa.gov/nextgen/programs/adsb/pilot/itp/), which to my knowledge hasn't really gone very far just yet. Anybody know if there's been any progress in making ITP a real thing?
I believe it has been ascertained that, once a sufficiently large number of people start using this, the end result is that traffic jams move from one location to a different one, and then back, as people readjust. Thus, instead of having a huge traffic jam in a location, we end up with a round-robin succession of not significantly smaller traffic jams in several different locations.
There must be a lot of traffic jams over the ocean.
Is the idea that flight routes aren't already optimally planned? That existing weather systems that might impact a specific flight aren't built into the flight plan, with fine adjustments made by pilots to alter course based on actual flight path conditions?
The summary makes it sound like planes aren't already flying the shortest possible path already. I mean, airspace over the open ocean is pretty goddamn empty, it's not like they're trying to avoid a jam-up on the 405.
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
Sounds cool, but airports have limited gates and work to a schedule. You can't just rock up ahead of your scheduled arrival time.
On the longest flights like the Qantas service between Perth and London (17h20m), the planes can come in up to one hour ahead of the scheduled arrival time if they encounter favourable winds.
The airline may save money on fuel, but pays money in fines from the airport for not sticking to schedule and the passengers will be spending the same amount of time in the cabin as the plane may have to wait for its gate to open up.
long haul navigations services worked from the very beginning thanks to shortwave radio services.
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.