5 ms·

> Second problem landing strips, which also are limited (limited length, limited width). Direct-to-tower delivery. Removes the need for transport on the ground

> Second problem landing strips, which also are limited (limited length, limited width). Direct-to-tower delivery. Removes the need for transport on the ground for the last miles and the need for a crane.

simne 3y ago
That is problem. You sure could make tiny strip (10m x 250m), nearly everywhere, even at the center of old city. But large planes need much larger strips, for example typical international airport have strip 30m x 1600m. Why so much difference, because economy. It is much more effective to make large strips in large cities (or near them), than to make off-road planes (google Bush plane) which will have much more expensive cost to transport weight-kilometer or passenger-kilometer. From where become expensiveness. Well, most effective planes flight fast at high atmosphere (because speed of sound is significantly higher in low pressure), but they also have high landing speed, and unfortunately, brakes (very similar to automobile) need to dissipate all energy from speed, calculated from simple formula (m*v^2)/2, so with double speed have quadruple energy. Energy dissipation from plane brakes is really big problem, so big that nearly all big planes have special "thermo-accumulating" weights inside landing gear, which considered to heat fast when braking and then few hours dissipate heat. Extreme example was Concord, on which brakes cooling about 11 hours after landing. Bush planes are slow, so they don't have this problem. Second problem, because of engineering considerations (physics), large planes usually are tall, but not too wide inside, and very big loads are just considered to transport in "horseman" configuration, mean load placed on top of plane, so need special crane to load/unload.
- almostnormal 3y ago
  GGGP was suggesting use of an airship.
  - simne 3y ago
    And who will build network of hangars for it? Aliens?

simne 3y ago

That is problem. You sure could make tiny strip (10m x 250m), nearly everywhere, even at the center of old city. But large planes need much larger strips, for example typical international airport have strip 30m x 1600m. Why so much difference, because economy. It is much more effective to make large strips in large cities (or near them), than to make off-road planes (google Bush plane) which will have much more expensive cost to transport weight-kilometer or passenger-kilometer. From where become expensiveness. Well, most effective planes flight fast at high atmosphere (because speed of sound is significantly higher in low pressure), but they also have high landing speed, and unfortunately, brakes (very similar to automobile) need to dissipate all energy from speed, calculated from simple formula (m*v^2)/2, so with double speed have quadruple energy. Energy dissipation from plane brakes is really big problem, so big that nearly all big planes have special "thermo-accumulating" weights inside landing gear, which considered to heat fast when braking and then few hours dissipate heat. Extreme example was Concord, on which brakes cooling about 11 hours after landing. Bush planes are slow, so they don't have this problem. Second problem, because of engineering considerations (physics), large planes usually are tall, but not too wide inside, and very big loads are just considered to transport in "horseman" configuration, mean load placed on top of plane, so need special crane to load/unload.

almostnormal 3y ago
GGGP was suggesting use of an airship.
- simne 3y ago
  And who will build network of hangars for it? Aliens?