Got asked so many times who that infamous “L888 guy” was..
So, myth busted: L888 is no “guy”, but an airway - a very spectacular one.
nicknamed “Silk road airway”, it‘s the shortest route from Europe to SE Asia, a THE highway to HKG. From NW China, just after the Kazakh border, it leads across the Tian Shan mountain range and the Takla Makan Desert.
It’s a rather hostile (but stunningly beautiful) scarcely populated area - which makes L888 very special for #flightplanning.
Given the mountains (and remote location) prevent normal VHF radio communication / radar surveillance, L888 is a FANS (future air navigation system) airway - with COM / SUR via satellite connection (which is why L888 was established only in the year 2000).
So, no SATCOM, no L888 - you’d be stuck with conventional routes via Middle East, or further north around the mountains (“fellow” trans Himalaya airways, ie. Y1, pose similar challenges).
Terrain rises to ~27000ft, minimum safe altitude to ~28000ft for long distances on and around L888 (center right). this is an issue - in case of decompression (i.e. having to descend to FL100).
The solution: special escape routes - effectively permitting a slalom descent around terrain, they lead to one of the few airports in the area (eg ZWWW/Urumqi) for a diversion.
flighttime above FL100 will still exceed the 15 min oxygen reserve normally carried - so to be dispatched on L888, a #plane will need additional oxygen bottles.
We calculate an escape scenario for every flight, assuming a pressurization fail at the most critical point, emergency descent, and diversion via one of the escape routes (bottom right, dark blue). the resulting long flighttime in low level may easily require not just extra O2, but also additional fuel.
To make things worse,
NOTAMs regularly close part of the route,so good planning and follow-up’s the motto — and we’ll probably be rewarded with a nice, short #flighttime!
and if weather plays along, our #pilot(s), #cabincrew and passengers hopefully have a scenic flight with breathtaking views on the Top of the World - from even higher above.