5 ms·

> Such aircraft are complex to control I wonder if 737 Max is making them rethink this already. I love how it looks though.

dotancohen 7y ago
This has absolutely nothing to do with the 737 Max. Airbus in particular has been using fly-by-wire for years. The issue with the 737 Max is that it felt different to control under different flight conditions from the classic 737 and Boeing tried to patch that difference in software. There would be no such issue in a new from-the-CAD-file-up airframe.
- qaq 7y ago
  And there are failure modes where solution is basically reboot the computer. This would not go well in wing body design.
  - dotancohen 7y ago
    Maybe you should tell that to Northrup Grumman.
    - qaq 7y ago
      Are you saying Airbus is equipping planes with ejection seats like Northrup Grumman?
      - dotancohen 7y ago
        Are you saying that ejection seats are considered safe for use when your computer fails?
        qaq 7y ago
        It’s not controlled by flight computer
  - doikor 7y ago
    How is this any different from current Airbus planes? They are all fly by wire. If you turn off the computer in them you will lose all control. This is why they have a bunch of redundancy built in.
    - qaq 7y ago
      There is some level of mechanical control. The airframe is stable in wing design computer is continuously adjusting control surfaces it's not flyable by a human.
hobofan 7y ago
The 737 Max situation (among other things) stems from trying to cram a complex system into an existing simpler one while staying within existing constraints to avoid recertification. With a new design "from scratch" like this which would need new certification anyway, this wouldn't be an issue.
GuB-42 7y ago
There is nothing wrong with fly-by-wire and full authority controls as long as it is done correctly, it can even be more reliable than traditional mechanisms. The way these things are made reliable is by redundancy and formal testing. The Boeing 737 Max MCAS had neither: it relied on a single angle of attack sensor and the software wasn't certified up to the appropriate level. The big mistake was that they gave the system more authority than what it was originally designed for, without an appropriate requalification.
- jillesvangurp 7y ago
  Exactly. MCAS had only one goal: making the Boeing Max feel like the old Boeings by fiddling with the trim so that expensive retraining could be avoided. A fly by wire solution would have resulted in more design changes in the cockpit thus requiring a new type rating for lots of pilots. IMHO it is entirely fixable technically but of course the scrutiny of the FAA on this and the resulting steady flow of management fuckups, more potential issues being unveiled, and the apparent failure of the certification process is pretty much guaranteeing this to take quite long. Last year I was still optimistic it would fly again soon but given the recent trickle of more issues, I think this is going to be a pro-longed grounding. Airbus had it's fair share of incidents involving fly by wire in the eighties and nineties. However, more recent incidents seem to be not related to that anymore (terrorist attacks, bird strikes, bad weather/decision making, etc.). So, fly by wire is entirely safe if done properly these days and also not optional for flying most modern military planes. Airbus basically laid the foundation for their current success in the market right then. IMHO pilots are increasingly becoming safety pilots (i.e. emergencies and unusual situations are the only times they fly manually) and we're not that long away from fully autonomous planes. Right now, aside from takeoff and landing, most passenger planes are controlled via the auto pilot only. The pilot doesn't touch the yoke and instead fiddles with buttons to direct the auto pilot. Cat III landings can be fully automated technically and certified pilots are required to fly a certain amount of fully automated touchdowns regularly. The military routinely flies remotely controlled drones and fully autonomous drones already. So, a design like this could make sense. 20% reduction in drag is quite a lot of gain and fly by wire has been used for decades to make all sorts of otherwise unstable configurations flyable.
rsynnott 7y ago
Airbus has a lot of experience with fly-by-wire. The problem with the 737 MAX wasn't fly-by-wire as such.

dotancohen 7y ago

This has absolutely nothing to do with the 737 Max. Airbus in particular has been using fly-by-wire for years. The issue with the 737 Max is that it felt different to control under different flight conditions from the classic 737 and Boeing tried to patch that difference in software. There would be no such issue in a new from-the-CAD-file-up airframe.

qaq 7y ago
And there are failure modes where solution is basically reboot the computer. This would not go well in wing body design.
- dotancohen 7y ago
  Maybe you should tell that to Northrup Grumman.
  - qaq 7y ago
    Are you saying Airbus is equipping planes with ejection seats like Northrup Grumman?
    - dotancohen 7y ago
      Are you saying that ejection seats are considered safe for use when your computer fails?
      - qaq 7y ago
        It’s not controlled by flight computer
- doikor 7y ago
  How is this any different from current Airbus planes? They are all fly by wire. If you turn off the computer in them you will lose all control. This is why they have a bunch of redundancy built in.
  - qaq 7y ago
    There is some level of mechanical control. The airframe is stable in wing design computer is continuously adjusting control surfaces it's not flyable by a human.

hobofan 7y ago

The 737 Max situation (among other things) stems from trying to cram a complex system into an existing simpler one while staying within existing constraints to avoid recertification. With a new design "from scratch" like this which would need new certification anyway, this wouldn't be an issue.

GuB-42 7y ago

There is nothing wrong with fly-by-wire and full authority controls as long as it is done correctly, it can even be more reliable than traditional mechanisms. The way these things are made reliable is by redundancy and formal testing. The Boeing 737 Max MCAS had neither: it relied on a single angle of attack sensor and the software wasn't certified up to the appropriate level. The big mistake was that they gave the system more authority than what it was originally designed for, without an appropriate requalification.

jillesvangurp 7y ago
Exactly. MCAS had only one goal: making the Boeing Max feel like the old Boeings by fiddling with the trim so that expensive retraining could be avoided. A fly by wire solution would have resulted in more design changes in the cockpit thus requiring a new type rating for lots of pilots. IMHO it is entirely fixable technically but of course the scrutiny of the FAA on this and the resulting steady flow of management fuckups, more potential issues being unveiled, and the apparent failure of the certification process is pretty much guaranteeing this to take quite long. Last year I was still optimistic it would fly again soon but given the recent trickle of more issues, I think this is going to be a pro-longed grounding. Airbus had it's fair share of incidents involving fly by wire in the eighties and nineties. However, more recent incidents seem to be not related to that anymore (terrorist attacks, bird strikes, bad weather/decision making, etc.). So, fly by wire is entirely safe if done properly these days and also not optional for flying most modern military planes. Airbus basically laid the foundation for their current success in the market right then. IMHO pilots are increasingly becoming safety pilots (i.e. emergencies and unusual situations are the only times they fly manually) and we're not that long away from fully autonomous planes. Right now, aside from takeoff and landing, most passenger planes are controlled via the auto pilot only. The pilot doesn't touch the yoke and instead fiddles with buttons to direct the auto pilot. Cat III landings can be fully automated technically and certified pilots are required to fly a certain amount of fully automated touchdowns regularly. The military routinely flies remotely controlled drones and fully autonomous drones already. So, a design like this could make sense. 20% reduction in drag is quite a lot of gain and fly by wire has been used for decades to make all sorts of otherwise unstable configurations flyable.

rsynnott 7y ago

Airbus has a lot of experience with fly-by-wire. The problem with the 737 MAX wasn't fly-by-wire as such.