* Many warnings to pilots are irrelevant, outdated
* Air Canada incident in 2017 highlighted problems
* Pilots want warnings prioritised, in plain English
When it came time to land at San Francisco on July 7, 2017, the pilots of an Air Canada jet could not recall a critical piece of information buried on page eight of a 27-page briefing package: the closure of one of the airport's two runways.
Mistaking the runway they were cleared to land on for the one that was closed, the fatigued pilots chose the wrong reference point and lined up to land on a parallel taxiway instead. They came within seconds of colliding with four planes.
More than three years later, a global campaign has been launched to improve aviation safety by reducing the kind of information overload experienced by the pilots of Air Canada 759.
The reform of the more than century-old system of Notices to Airmen (NOTAMs) - originally modelled after Notices to Mariners - is part of a wider push to make aviation simpler, particularly in the wake of two Boeing 737 MAX crashes.
For long-haul flights, there can be up to 200 pages of NOTAMs for pilots to review on paper or an iPad, many of them as irrelevant as general bird hazard warnings, grass-cutting at airports or low-altitude construction obstacles relevant only to helicopters and light planes.
For decades, such standardised bulletins issued by national air navigation authorities - part of a global safety regime overseen by the United Nations - have helped to keep aviation safe.
But the industry has grown so large that the noise created by redundant warnings is increasingly seen as a hazard.
Displayed in unpredictable order and written in a telegraphic code conceived decades ago, the upper-case notices are riddled with byzantine abbreviations that can pose problems even for experienced pilots when they are overworked, particularly for non-native English speakers.
A warning that a navigation aid will be unavailable at Hong Kong International Airport for less than two hours in late May, for example, appears as:
A0290/21 NOTAMN Q) VHHK/QNMAU/IV/NBO/AE/000/999/2219N11355E005 A) VHHH B) 2105252130 C) 2105252329 E) SIU MO TO DVOR/DME 'SMT' 114.80 MHZ/CH95X NOT
In the United States, investigators have warned for years that the torrent of data could either overwhelm pilots or just be ignored.
Many are issued to avoid legal liability rather than improve safety, say experts.
"(NOTAMs) are just a bunch of garbage that nobody pays any attention to," U.S. National Transportation Safety Board Chairman Robert Sumwalt said at a 2018 hearing on the Air Canada incident, which helped spur the global campaign for change.
Now, the UN International Civil Aviation Organization (ICAO) is leading efforts to overhaul the system.
Its first step is to get rid of outdated NOTAMs. Officially, the warnings are supposed to expire after 90 days. But 20% of the more than 36,000 active globally notices are older than that, according to ICAO.
"You can imagine how incredibly frustrating it is for crews because basically what we're saying is, 'Here's 200 pages of junk. In there is one NOTAM that could potentially end your career, or place your aircraft and passengers in danger, and it's up to you to find it,'" said Mark Zee, the founder of flight operations advisory firm OPSGROUP, who has played a key role in lobbying for change.
The next step, which Zee said was slated for 2022, will prioritise the most important warnings at the top of the briefing package and allow airlines to filter out those not relevant for their crews.
A final step - long overdue, according to pilots - would be to change the format of NOTAMs to make them more reader-friendly.
Airspace NOTAMs, for example, are often given as a set of latitudes and longitudes that are meaningless unless pilots have time to chart them - and they do not, Australian Federation of Air Pilots Safety and Technical Director Stuart Beveridge said.
"So we've actually suggested they move into the 21st century and look at upper and lower case, punctuation, plain standardised language, time formats that are not just strings of numbers, and where possible, graphical information," he said.
While the campaign is promising, it demonstrates the glacial pace of change in global aviation, safety experts say, adding it could take years more before all countries put changes into effect.
In Albania, for example, there is an active NOTAM issued in 2000 that provides pilots with a telephone number to call should they have a Y2K-related communications problem.
"So I'm basically reading about Y2K thinking they can't possibly mean that thing from 20 years ago that never happened," Zee said.
"And right at the bottom there's one that says, for example, no jet fuel available for two weeks. I've missed it. Now I've flown in and I can't get fuel to get back out again."
