3 ms·

No One Can Explain Why Planes Stay in the Air

4 points by _ttg 5y ago

macilacilove 5y ago
"The page you were looking for could not be found. " Maybe someone found out since then. :)
- _ttg 5y ago
  Oops. submitted the wrong link and it doesn't seem like I can edit the url https://www.scientificamerican.com/article/no-one-can-explain-why-planes-stay-in-the-air/ https://www.scientificamerican.com/article/no-one-can-explai...
  - PaulHoule 5y ago
    Delete it and try again. The title sounds a little cringeworthy to me because it sounds like it is about the fake controversy about the Bernoulli Principle. The Bernoulli Principle doesn't explain lift from aircraft wings at all (particularly in that the 'angle-of-attack' is so critical to lift) and all reference to it should have been excised circa 1960 but oddly it has survived in this narrative that there are two competing theories about lift that has chronically survived in places like the manual for the 1980 Microsoft Flight Simulator.
    - simonblack 5y ago
      Bernoulli's Principle explains the force which is (wrongly) called 'lift'. The force is perpendicular to the aerofoil, whether the aerofoil is top-towards-ground (plane flying upside down) or top-towards-sky (plane flying right way up). The angle of attack is always measured relative to the airflow, whether that relative airflow is upwards or downwards or sideways. Note that at zero degrees of angle of attack, the wing still provides 'lift' due to the Bernoulli Principle. At negative degrees angle of attack, the wing moves 'downwards' relative to the airflow, when the angle of attack is positive the wing moves 'upwards' relative to the airflow. NOTE: the terms 'upwards' and 'downwards' here are directions relative to the aerofoil/wing and have nothing at all with the orientation of the wing to the ground. (If a plane is flying upside-down, 'downwards relative to the wing' would lead to an increase in the plane's altitude.) When the angle of attack exceeds roughly 15 degrees relative to the airflow the fluid ('air', in other words) becomes turbulent which destroys the 'lift' and the wing is said to be 'stalled'. Being stalled is a dangerous situation and leads to aircraft literally falling out of the sky.

4 points by _ttg 5y ago

macilacilove 5y ago

"The page you were looking for could not be found. " Maybe someone found out since then. :)

_ttg 5y ago
Oops. submitted the wrong link and it doesn't seem like I can edit the url https://www.scientificamerican.com/article/no-one-can-explain-why-planes-stay-in-the-air/ https://www.scientificamerican.com/article/no-one-can-explai...
- PaulHoule 5y ago
  Delete it and try again. The title sounds a little cringeworthy to me because it sounds like it is about the fake controversy about the Bernoulli Principle. The Bernoulli Principle doesn't explain lift from aircraft wings at all (particularly in that the 'angle-of-attack' is so critical to lift) and all reference to it should have been excised circa 1960 but oddly it has survived in this narrative that there are two competing theories about lift that has chronically survived in places like the manual for the 1980 Microsoft Flight Simulator.
  - simonblack 5y ago
    Bernoulli's Principle explains the force which is (wrongly) called 'lift'. The force is perpendicular to the aerofoil, whether the aerofoil is top-towards-ground (plane flying upside down) or top-towards-sky (plane flying right way up). The angle of attack is always measured relative to the airflow, whether that relative airflow is upwards or downwards or sideways. Note that at zero degrees of angle of attack, the wing still provides 'lift' due to the Bernoulli Principle. At negative degrees angle of attack, the wing moves 'downwards' relative to the airflow, when the angle of attack is positive the wing moves 'upwards' relative to the airflow. NOTE: the terms 'upwards' and 'downwards' here are directions relative to the aerofoil/wing and have nothing at all with the orientation of the wing to the ground. (If a plane is flying upside-down, 'downwards relative to the wing' would lead to an increase in the plane's altitude.) When the angle of attack exceeds roughly 15 degrees relative to the airflow the fluid ('air', in other words) becomes turbulent which destroys the 'lift' and the wing is said to be 'stalled'. Being stalled is a dangerous situation and leads to aircraft literally falling out of the sky.