Absolutely tons between 10K-20k, though.

EvanAnderson 6 hours ago | parent | next [-]

My view on ADSBexchange is centered on CMH, zoomed out to Washington D.C. to the east, and filtered by 18K up I've got 142 aircraft.

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_heimdall 6 hours ago | parent | prev [-]

This tracks with what I has seem elsewhere. I don't have the details handy now, but the communication system used for long range handoffs for flights above 18,000 ft seems to be what is impacted. Keeping planes below that deck would keep them bouncing more frequently between shorter range towers but at least still tracked and in communication.

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sokoloff 6 hours ago | parent [-]

Jet efficiency that low is horrendous though. I suspect a lot of that lower is piston and turboprop, even today.

	▲	_heimdall 4 hours ago \| parent [-]
		Oh its absolutely bad fuel efficiency. I'd expect they go to that altitude where communication is still reliable and do everything they can to get flights on the ground safely regardless of inconvenience or fuel inefficiency.