Pretty sure all current large commercial planes have 3 ADIRUs each with its own laser gyro. This is not to say there have not been issues with correctly chosing the right 2 of 3...
The assumption is you’ll only lose one at a time (because most everything is isolated, duplicated, and redundant), so there are three because one will be odd man out, and you ignore that one.
Nope.
How Zero-G Planes Work - YouTube
That weight on the string would be doing exactly what the presenter’s body would be doing. Floating
Yes, they are many illusions that humans suffer from (somatogravic as an example) But, that’s why they pay us the big bucks to not react to those. You can put me upside down in the dark, with no horizon) and give me a partial panel and I should be able to recover from it.
I’ve actually always joked about a what a great thing a yaw string would be on nose of the airplane. With a piece of string and the sound of the slipstream (airspeed cue) an experienced pilot should be able to fly the airplane and need nothing else. As I fly a visual approach (the hardest thing when flying a 60 ton airplane), I look through the windscreen at an aiming point on the runway and walk the thrust levers back and forth. It’s physics: you put a correction in, and wait. Your eyes move fast and your hands move slow.
As far as stalls goes, even when the stall is accelerated, the airplane tells you what’s happening. As the laminar airflow separates it generates buffet-It’s unmistakable. So, even if all the primary and secondary indications are inoperative, the buffet is there, and you feel it in the airframe, long before the actual stall.
Nope.
You’d be falling at that stage and zero g and know it’s game over. Before you go into the stall the weight + string angle would be telling you you were headed for disaster.
But you’ve just given me an idea for another super simple KYAG ( ‘kiss your *** goodbye’) sensor.
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AOA is displayed on the PFD (primary flight display) as an option above and to the right in the 737. My airline opted for AOA in our MAX fleet. AOA should be displayed in all aircraft and taught in primary training.
Funny how many pilots miss that though - again , I respect what you guys do and cannot imagine how stressful an impending stall must be, but it seems to happen too regularly for comfort.
As a pilot do you have a view on this? Human factors engineering maybe?
As a pilot do you have a view on this? Human factors engineering maybe?
I think some pilots don't know. I've seen those "Air Craft Disaster" videos where the pilots ignored the instruments and flew by the seat of their pants... and crashed. I've seen where they flew by the instruments and ignored their gut instincts (what they're supposed to do I guess) and crashed because the instruments were way off. I've seen where the plane was overspeed (because it was free falling) and the pilots thought they were flying level at altitude.
Some of these were instrument error, some pilot error, some both. A lot can go wrong!
Ummm.... if that were true how does the big airliner making the zero-G runs in the above video do it over and over with out it being “game over”?
No. Pitch attitude and AOA are not analogous.
Also, in this aircraft, that weight on a string would be showing normal the entire time, hence why the liquid is pouring out, into the glass, at one G, regardless of the attitude of the airplane -
Bob Hoover trick in 2006 - YouTube
I have a huge amount to say on the subject, but then that would make feel like I'm at work 😀
When we go to the "school house" each year we spend the vast majority of our time on how engineering and human factors work (or do not work) together in the cockpit. The entire training event and footprint are laid out to explore how we solve problems and how barriers to communication prevent solutions: It's in everything that we do. When that years events are complete, we begin inventing new ones for the following year, which are partly or wholly based on real occurrences / factors, like the ones that led to these unfortunate events.
Cheers,
Greg
They do know. What’s happening is that they aren’t using it as a resource. There’s a very long chain of events in an accident (the chain could be months or years long for a single accident). What we do is break that chain through the use of training, experience, and knowledge (systems and aerodynamic).
“ Ummm.... if that were true how does the big airliner making the zero-G runs in the above video do it over and over with out it being “game over”?”
Zero G flight profile and stalling are are not the same. In a stall your forward speed drops to a very low value and the lift collapses. In a zero G flight profile you forward speed is much higher.
Zero G flight profile and stalling are are not the same. In a stall your forward speed drops to a very low value and the lift collapses. In a zero G flight profile you forward speed is much higher.
Yeah, I saw some where it seemed like the pilots should have known what was going on. One I especially remember was when the altimeter showed the plane was climbing and at high altitude when the opposite was true. The pilots had the airbrakes on because the speed was increasing uncontrollably. The sticks were shaking. The horizon indicators were erratic and an obvious clue that something was wrong. The pilot was still trying to engage the autopilot for about the tenth time when they crashed into the ocean.
It was night, just off the coast. Instead of calling an emergency and asking for an escort, the captain decided to soldier on. The crew was turning the plane around for an emergency landing, flying blind over water. They knew the plane was messed up as soon as they took off, but still thought they could fly it across the ocean.
There's so much going on, I was just WTF the whole time. Abort the flight while you can still see enough to fly without instruments.
Again, no. Zero G and stalling have noting to do with each other. I have spent a lot of time at zero G with zero forward velocity, and I’ve also stalled an aircraft with much higher than normal forward velocity.
Stalling is when the wing exceeds critical AOA and the airflow becomes detached. Period. It can happen at any attitude, altitude, or speed.
Zero-g happens when the forces on the aircraft are exactly equal to the forces of gravity - I.E., the aircraft is moving exactly at the acceleration of gravity and the occupants are ‘falling’ inside with the aircraft doing the exact same thing. This is why they fly a parabola - you get longer time weightless as the aircraft is going up and slowed by gravity, and also you keep your total velocity under control, as going too fast has some very real consequences, hence why you don’t just push over... it would work, but you’d accelerate too fast since you already had flying velocity.
Anyway, look again at the zero-g video during the shots of the plane from the outside, and you’ll observe something that only exists on flights like those - the complete absence of wing flex. Airliner wings, by deign and necessity, need to be fairly bendy, and yet in that footage the wing is almost unnaturally flat because it isn’t being used at all. It’s rather neat.
During the zero-g maneuver, the AOA is going to be zero, regardless of airspeed, forward velocity, and pitch.
Although in certain situations this is true, it is not what is stalling the aircraft. Exceeding critical AOA is what’s causing the stall. You can stall the wing with the nose pointed straight down and the airspeed higher than cruise.
Compared to what...? Again, Ive been at zero g in an aircraft with zero forward velocity, at air speeds much lower than the book’s “stall speed” and also at much higher speeds.
If you’ve been at zero g and aircraft has stalled, you’ve made an excellent recovery.
Not really an option for a 100 ton airliner. And certainly not representative of a large ‘vomit comet’ flying a zero g profile.
Not really an option for a 100 ton airliner. And certainly not representative of a large ‘vomit comet’ flying a zero g profile.
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