Aviators, how did you overcome a real life situation where your aircraft switched to Direct Law and how stressful is it going into Direct Law unexpectedly?
Posted by SkydivingSquid@reddit | aviation | View on Reddit | 6 comments
Swimming_Way_7372@reddit
There was a Delta A350 that lost their auto pilot and auto thrust oast year and had to declare an emergency. I can't imagine what they would have done if they reverted to Direct law.
spacecadet2399@reddit
I assume you mean in Airbus planes since that's where the term is most used.
I've never had it happen. We're trained for it, obviously, but not really a tremendous amount because we're all pilots and we've all flown in what amounts to "direct law" in various other airplanes. It's kind of assumed we know how to control an airplane directly. And it doesn't feel much different than normal law anyway. You just have to manually trim and stuff like that, which is all I ever did for my first 1,500 hours, flying GA.
But, it would be a bad day if the airplane reverted to direct law. That would mean a pretty major failure, and probably more than one, which would be the thing we'd actually be most worried about in that situation. Actually flying in direct law should be almost automatic for any pilot. The hard part would be to not be distracted by whatever actual emergency was going on. That's often the hardest part in any emergency, but it would be even more important for the pilot flying to actually focus on the flying when in direct law. We do sometimes take for granted in Airbus planes that we have protections for various things, and someone flying for many years in Airbus would probably have that pretty ingrained, so you'd really have to just get in a different mental mindset and let the non-flying pilot deal with the emergency.
Lensatic_wilkinson@reddit
For what is worth, the 737 is TECHNICALLY always in direct law lol, no one seems to mind all that much.
Every-Progress-1117@reddit
Assuming you mean Airbus modes of operation - it is incredibly unlikely that this would happen. Such systems are designed with the idea of managed degradation, that is the systems hand over control to the pilot (or vice versa) in a structured way.
Of course, this can be mismanaged by the pilots and catastrophic failures can occur, but TBH, would be so catastrophic you're not really going to be that concerned about the niceties of which protection modes are in operation.
There's famous lecture on aircraft automation that is very much worth watching called Children of the Magenta Line: https://www.youtube.com/watch?v=5ESJH1NLMLs It'll help you understand how automation works.
Apprehensive_Cost937@reddit
There's nothing scary about flying the aircraft in direct law, just need to use manual trim, and that's it.
Thousands of airliners are in the air every day, whose every second of the flight is done in what you'd call "direct law", and they fly just fine.
Independent-Reveal86@reddit
It's never happened to me. It would be a very rare event to go to direct law unexpectedly, "normally" you get direct law after putting the gear down on approach when you were previously in alternate law. The relevant checklist reminds you of this. I've never been in alternate law either, except in the sim. Direct law isn't scary though, it just flies like a normal aeroplane. FBW airliners aren't like unstable fighter jets that have computers rapidly working to make the aircraft seem flyable, FBW in airliners consists of protections and helpers that just make life easier and safer.