Could a marble prevent a plane crash?
Discussion
Didn’t know where to put this but this seemed the right place.
I watch (too many) air crash investigation programmes.
One of the things that is often part of the cause of an accident are pilots becoming situationally confused.
They, in some cases, can’t tell up from down and which way they are turning.
Sometimes this is exacerbated by a instrument failure e.g. the attitude indicator is false reading etc.
It occurred to me that if you had a sealed clear tube that was affixed level to the wings with a marble in it, it would clearly indicate if you were pitching left or right. If you also had one running directionally nose to tail then you’d know if you were nose up or nose down.
Clearly this would be fairly impervious to mechanical failure and as a last resort would be prettty clear to see you were pitching one way or the other.
So…why is this not the perfect, low cost solution?
I watch (too many) air crash investigation programmes.
One of the things that is often part of the cause of an accident are pilots becoming situationally confused.
They, in some cases, can’t tell up from down and which way they are turning.
Sometimes this is exacerbated by a instrument failure e.g. the attitude indicator is false reading etc.
It occurred to me that if you had a sealed clear tube that was affixed level to the wings with a marble in it, it would clearly indicate if you were pitching left or right. If you also had one running directionally nose to tail then you’d know if you were nose up or nose down.
Clearly this would be fairly impervious to mechanical failure and as a last resort would be prettty clear to see you were pitching one way or the other.
So…why is this not the perfect, low cost solution?
The_Nugget said:
essayer said:
Bank left. Marble rolls left. Makes sense.
Now enter a dive. What happens to the marble? It goes up(+right). Now pilots are confused.
So the answer is g force renders it a stupid idea?Now enter a dive. What happens to the marble? It goes up(+right). Now pilots are confused.
I've seen a two axis instrument in a museum with curved glass tubes of alcohol with bubbles in them; a variation on the theme of the spirit level.
Modern equivalent would be the gyro compensated artificial horizon.
Error_404_Username_not_found said:
The_Nugget said:
essayer said:
Bank left. Marble rolls left. Makes sense.
Now enter a dive. What happens to the marble? It goes up(+right). Now pilots are confused.
So the answer is g force renders it a stupid idea?Now enter a dive. What happens to the marble? It goes up(+right). Now pilots are confused.
I've seen a two axis instrument in a museum with curved glass tubes of alcohol with bubbles in them; a variation on the theme of the spirit level.
Modern equivalent would be the gyro compensated artificial horizon.
The marble was just a pre production prototype.
essayer said:
Bank left. Marble rolls left. Makes sense.
Now enter a dive. What happens to the marble? It goes up(+right). Now pilots are confused.
You can bank left and the marble could roll to the right too.Now enter a dive. What happens to the marble? It goes up(+right). Now pilots are confused.
I don’t think pilots have a problem detecting which way they are being accelerated… it’s fairly obvious.
even sitting in seat 34A I can tell roughly whether the plane is level, climbing, descending or banking so f
k knows why a fully trained pilot would faithfully believe his faulty instruments that were telling him he was climbing when experience should tell him he was actually falling.
k knows why a fully trained pilot would faithfully believe his faulty instruments that were telling him he was climbing when experience should tell him he was actually falling. Kawasicki said:
essayer said:
Bank left. Marble rolls left. Makes sense.
Now enter a dive. What happens to the marble? It goes up(+right). Now pilots are confused.
You can bank left and the marble could roll to the right too.Now enter a dive. What happens to the marble? It goes up(+right). Now pilots are confused.
I don’t think pilots have a problem detecting which way they are being accelerated… it’s fairly obvious.
EDIT:expect that marble starts at 50 quid for a Cessna150 and only goes up from there.
Whats on Second said:
even sitting in seat 34A I can tell roughly whether the plane is level, climbing, descending or banking so fk knows why a fully trained pilot would faithfully believe his faulty instruments that were telling him he was climbing when experience should tell him he was actually falling.
Well, the pilots of Air France flight 447 managed to be completly confused about what they were experiencing & flew the aircrfat into the sea.k knows why a fully trained pilot would faithfully believe his faulty instruments that were telling him he was climbing when experience should tell him he was actually falling. Mr Pointy said:
Whats on Second said:
even sitting in seat 34A I can tell roughly whether the plane is level, climbing, descending or banking so fk knows why a fully trained pilot would faithfully believe his faulty instruments that were telling him he was climbing when experience should tell him he was actually falling.
Well, the pilots of Air France flight 447 managed to be completly confused about what they were experiencing & flew the aircrfat into the sea.k knows why a fully trained pilot would faithfully believe his faulty instruments that were telling him he was climbing when experience should tell him he was actually falling. Whats on Second said:
even sitting in seat 34A I can tell roughly whether the plane is level, climbing, descending or banking so fk knows why a fully trained pilot would faithfully believe his faulty instruments that were telling him he was climbing when experience should tell him he was actually falling.
The fairly interesting fact is that actually, you can't! (not always!)k knows why a fully trained pilot would faithfully believe his faulty instruments that were telling him he was climbing when experience should tell him he was actually falling. Instrument flying is a necessary part of pilot training precisely because what your body feels is happening may not in fact be what is happening. We normally rely on visual queues and mostly exist in a broadly 2 dimesional work (the ground) so us humans are really bad actually at "feeling" which way we are going.
https://en.wikipedia.org/wiki/Spatial_disorientati...
The other thing you can't feel, but that is critical to a plane, is the Angle Of Attack, the AOA, which is the angle at which the air hits the airframe, and may NOT be the actual direction in which it is travelling. An AOA gauge could well have saved AF447
Pilots are taught to "fly their instruments and not what they feel" for very good reason..........
Always remember that in the almost 120 years of manned powered flight, almost everything that a non-aeronautical engineer can think of has already been thought of by someone else.
And to those who think a pilot should always be able to tell which way the aircraft is pointing/moving, you really haven’t ever been truly disorientated.
And to those who think a pilot should always be able to tell which way the aircraft is pointing/moving, you really haven’t ever been truly disorientated.
MitchT said:
I once asked the same question but suggested a spirit level.....
Much better. On the right lines since the gas bubble is much less sensitive to G forces than a marble or similar. Which is why WW2 bombers were equipped with bubble sextants for navigators to fiddle with. Strangely there was a brief fashion in the 30s for bubble clinometers on ocean racing yachts but it's hard to imagine what useful purpose they served, beyond making money for the manufacturer.
Whats on Second said:
even sitting in seat 34A I can tell roughly whether the plane is level, climbing, descending or banking so fk knows why a fully trained pilot would faithfully believe his faulty instruments that were telling him he was climbing when experience should tell him he was actually falling.
Not always as easy as you think especially in a failure situationk knows why a fully trained pilot would faithfully believe his faulty instruments that were telling him he was climbing when experience should tell him he was actually falling. The_Nugget said:
Didn’t know where to put this but this seemed the right place.
I watch (too many) air crash investigation programmes.
One of the things that is often part of the cause of an accident are pilots becoming situationally confused.
They, in some cases, can’t tell up from down and which way they are turning.
Sometimes this is exacerbated by a instrument failure e.g. the attitude indicator is false reading etc.
It occurred to me that if you had a sealed clear tube that was affixed level to the wings with a marble in it, it would clearly indicate if you were pitching left or right. If you also had one running directionally nose to tail then you’d know if you were nose up or nose down.
Clearly this would be fairly impervious to mechanical failure and as a last resort would be prettty clear to see you were pitching one way or the other.
So…why is this not the perfect, low cost solution?
It's called a turn and slip indicator. Years ago, during instrument training, we were required to fly and shoot approaches on 'needle, ball and airspeed'. Partial panel is an emergency. The picture shows an electric, however they where originally powered by a vacuum pump or venturi.I watch (too many) air crash investigation programmes.
One of the things that is often part of the cause of an accident are pilots becoming situationally confused.
They, in some cases, can’t tell up from down and which way they are turning.
Sometimes this is exacerbated by a instrument failure e.g. the attitude indicator is false reading etc.
It occurred to me that if you had a sealed clear tube that was affixed level to the wings with a marble in it, it would clearly indicate if you were pitching left or right. If you also had one running directionally nose to tail then you’d know if you were nose up or nose down.
Clearly this would be fairly impervious to mechanical failure and as a last resort would be prettty clear to see you were pitching one way or the other.
So…why is this not the perfect, low cost solution?
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