6 ms·

So, they're not nearly as fast as you're describing, but Cirrus does have parachutes on a lot of it's planes: https://en.wikipedia.org/wiki/Cirrus_Airframe_Para

by dlgeek 8y ago

So, they're not nearly as fast as you're describing, but Cirrus does have parachutes on a lot of it's planes: https://en.wikipedia.org/wiki/Cirrus_Airframe_Parachute_System https://en.wikipedia.org/wiki/Cirrus_Airframe_Parachute_Syst...

namibj 8y ago
I know, the issue there is that if you deploy a parachute at over about Mach 0.4~0.5, you will either rip the airframe apart or reduce survival chances of large vertebrae due to the massive acceleration. The solution there would be going into a stall, as that usually serves to provide the drag needed to slow down to safe parachute speeds, but not so much that the airframe can't be reasonably build strong enough to not suffer damage that matters if one considers the plane scrap metal once it lands with the parachute. This is just too slow to get the main benefit of air travel, which is being able to go at barely subsonic speeds without handling being a massive headache. Of course you will have worse handling at barely subsonic speeds, due to any large deflection going transsonic and having the potential to result in loss of control. But that can easily be handled electronically, especially if the plane is at least somewhat aerodynamically stable, i.e. won't require constant corrections to not go into stall (like some modern fighter jets do).
- sokoloff 8y ago
  If you only have to go a couple hundred miles, the cruise speed isn't a significant factor to the overall trip time. Let the airlines handle the 1000+ mile trips (with all the associated hassles); slower airplanes don't give up near as much time on short legs. Door to door, I can beat the airlines on most trips under 1000 miles. I don't need to get to the airport 90 minutes ahead of departure, go through security, wait for boarding to complete, wait for pushback, connect through a hub, wait for bags, and can often land at an airport closer to where I want to be and have a rental car or cab waiting. The fact that cruise speed is only 215 mph/350 kph is made up for by all the slippage inherent in airline travel.
  - namibj 8y ago
    Yes, the one thing missing that would be being able to start from a normal road, and land on something similar, which could allow pretty much door-to-door is too hard to make work for how many could afford it.
    - sokoloff 8y ago
      In Alaska, Montana, Idaho, North Dakota, and South Dakota, it's legal to land on rural roads. Even in places where you can't land on roads, there are WAY more airports than you probably think in the US. It's about 19K, with a little over 5K of those being public use. (Even the private ones are often accessible with just a coordinating phone call.) Of those, fewer than 400 are "Primary" airports (defined as having scheduled commercial service and more than 10K enplanements [commercial passengers outbound] per year).
      - namibj 8y ago
        Yes, I know there are many airports. This is about starting from "The next road with sufficiently little traffic that has suitable clearance and curvature to start from", and maybe something like folding wings inwards or so to get it small enough for maneuvering it as a large car.

by dlgeek 8y ago

namibj 8y ago

I know, the issue there is that if you deploy a parachute at over about Mach 0.4~0.5, you will either rip the airframe apart or reduce survival chances of large vertebrae due to the massive acceleration. The solution there would be going into a stall, as that usually serves to provide the drag needed to slow down to safe parachute speeds, but not so much that the airframe can't be reasonably build strong enough to not suffer damage that matters if one considers the plane scrap metal once it lands with the parachute. This is just too slow to get the main benefit of air travel, which is being able to go at barely subsonic speeds without handling being a massive headache. Of course you will have worse handling at barely subsonic speeds, due to any large deflection going transsonic and having the potential to result in loss of control. But that can easily be handled electronically, especially if the plane is at least somewhat aerodynamically stable, i.e. won't require constant corrections to not go into stall (like some modern fighter jets do).

sokoloff 8y ago
If you only have to go a couple hundred miles, the cruise speed isn't a significant factor to the overall trip time. Let the airlines handle the 1000+ mile trips (with all the associated hassles); slower airplanes don't give up near as much time on short legs. Door to door, I can beat the airlines on most trips under 1000 miles. I don't need to get to the airport 90 minutes ahead of departure, go through security, wait for boarding to complete, wait for pushback, connect through a hub, wait for bags, and can often land at an airport closer to where I want to be and have a rental car or cab waiting. The fact that cruise speed is only 215 mph/350 kph is made up for by all the slippage inherent in airline travel.
- namibj 8y ago
  Yes, the one thing missing that would be being able to start from a normal road, and land on something similar, which could allow pretty much door-to-door is too hard to make work for how many could afford it.
  - sokoloff 8y ago
    In Alaska, Montana, Idaho, North Dakota, and South Dakota, it's legal to land on rural roads. Even in places where you can't land on roads, there are WAY more airports than you probably think in the US. It's about 19K, with a little over 5K of those being public use. (Even the private ones are often accessible with just a coordinating phone call.) Of those, fewer than 400 are "Primary" airports (defined as having scheduled commercial service and more than 10K enplanements [commercial passengers outbound] per year).
    - namibj 8y ago
      Yes, I know there are many airports. This is about starting from "The next road with sufficiently little traffic that has suitable clearance and curvature to start from", and maybe something like folding wings inwards or so to get it small enough for maneuvering it as a large car.