petej wrote: ↑Tue Mar 22, 2022 1:28 pm
inactionman wrote: ↑Tue Mar 22, 2022 11:48 am
TheFrog wrote: ↑Tue Mar 22, 2022 11:32 am
Suicide?
Is there no automatic protection build in to prevent extreme maneuvers?
I've been out of loop for a few years, but the simple answer is not really. There are stick shakers on Boeings* that make it hard/uncomfortable to get the aircraft into dodgy positions, but the pilot is the ultimate arbiter of intent.
Also worth noting that sensors etc can fail and it's possible to get into weird configurations as the aircraft gets a bit flummoxed - and, perhaps more significantly, the crew can misinterpret and start to contradict in all sorts of weird and wonderful ways. Especially if in a high-stress situation
* Airbus took a different approach and would essentially refuse or water down pilot commands to avoid e.g. stall, but in my understanding the 737 family is still cables and pulleys and direct mechanical/ hydraulic coupling so it can't 'undo' pilot commands, just add weight to the controls to try to make it difficult to do something daft.
Wasn't there a military airbus where a copilot got an object stuck/wedged near the controls putting it into a dive and the safety systems stabilised and levelled the aircraft?
I'm not aware of that case. I'd imagine it can be placed into autopilot in that situation, although that won't be of much use if it's in a nosedive and the autopilot can't recover. Other than that, the aircraft very rarely tries to overcome the pilot, as it simply cannot reliably infer what the pilot is intending to do and it's not good to have pilot and aircraft fighting each other.
As a notable exception, most large aircraft have mechanisms to prevent deep stalls, where they become too nose-up to maintain speed and essentially fall down flat, as these are almost impossible to recover at low altitudes - there's no airflow over control surfaces and not enough thrust to accelerate out of the problem. I'm not aware of anything limiting ability to dive - I understand that the aircraft won't pull out of an instructed dive because, as far as the aircraft logic can ascertain, the pilot is making the aircraft dive. The pilot in no situation or context ever wants to enter deep stall, which is why there are safety features* - I'm not sure if there are any limiters to angle of attack of dive, although there are sink rate and ground warnings galore.
I'll concede I haven't worked with Airbus or RR for 8 or 9 years so things might have moved on, but this would require rewrites of design and certification standards and ATA chapters etc (the 'rulebook' which governs how aircraft are designed, operated and maintained) which moves at pretty glacial pace.
* intended to be safe, anyway - good old MCAS on the 737 Max was a system designed to stop the nose pulling up under thrust, and that didn't work out so well.
eta: just found the case you're referring to - what a dipshit
https://www.theregister.com/2017/02/07/ ... t_martial/
Sounds like co-pilot got back into the cockpit - matey was on his tod with his camera beforehand - and regain control . Sounds like autopilot was on, but there are modes where it will still respond to stick commands.