5 ms·

> The same thing that happens in any other plane. https://en.wikipedia.org/wiki/List_of_aircraft_structural_failures https://en.wikipedia.org/wiki/List_of_airc

by blunte 5y ago

> The same thing that happens in any other plane. https://en.wikipedia.org/wiki/List_of_aircraft_structural_failures https://en.wikipedia.org/wiki/List_of_aircraft_structural_fa... The faster you are traveling (which really matters as a factor of the drag you are experiencing), the more serious any event is which changes the shape of your vehicle. Even non structural failures, such as an engine cowling coming off mid-flight can strike other parts of the aircraft, resulting in damage and changes to the structure. Tolerances for these events are much lower the faster you're going, meaning the outcome is more likely to be severe if you're traveling much faster than we currently do with passenger aircraft. Military fighters are built with higher tolerances and structural strength (and come in heavier, requiring more fuel and reducing range). Commercial aircraft are just impractical to operate safely at such high speeds. With respect to diversions and changes of route, you have to consider several things. Faster, heavier aircraft need longer runways to land. That limits your alternate landing choices. Diversions may cost you more fuel since they may be much greater distances away. And you cannot simply make a "sharp turn" at high speed. Your passengers (and the airframe on a large craft) are not prepared for 4G turns. They aren't even designed for 2G turns. Ask yourself this, can you turn your car as sharply at highway speed as you can in the parking lot? Sure you can slow down and then turn, but that takes time. That would not be considered "sharp". So while you're decelerating and turning, you are eating up great distances. It would be easy to overshoot a nearby location; thus you would need to plan ahead, take big slow turns, etc. Do you have enough extra fuel for that? Are you able/allowed to pass through all airspaces conveniently, or will that require extra planning and maneuvering? The complexity of flying larger and/or faster aircraft is much more than one might think.

stouset 5y ago
> The faster you are traveling (which really matters as a factor of the drag you are experiencing), the more serious any event is which changes the shape of your vehicle. Even non structural failures, such as an engine cowling coming off mid-flight can strike other parts of the aircraft, resulting in damage and changes to the structure. Yes, an engine falling off will be more impactful to a plane traveling at supersonic speeds. But these types of incidents are an extremely minor fraction of overall failures, and particularly during cruise at altitude (e.g., when the risk of bird strikes is minimal). Engineering steps can be taken to minimize risks like this further since the consequences of failure are higher. > Commercial aircraft are just impractical to operate safely at such high speeds. This argument was made when the first jetliners were being rolled out too. It carries about as much weight now as it did then. > Faster, heavier aircraft need longer runways to land. That limits your alternate landing choices. Diversions may cost you more fuel since they may be much greater distances away. This hasn't stopped faster, heavier aircraft from becoming commercial successes so far. A diversion is already extremely expensive for a myriad of reasons. Schedules, aircrew, and sometimes planes have to be shuffled around. Stranded passengers often need accommodation and/or alternative transport arranged. Airfare credits are often handed out. Incurring slightly higher fuel costs from having to divert a bit farther is just not that significant of a factor here, and one that is easily compensated for by adjusting ticket prices. Bumping the cost of an uncommon, already-expensive event by a few percentage points just doesn't move the needle much. > And you cannot simply make a "sharp turn" at high speed. Your passengers (and the airframe on a large craft) are not prepared for 4G turns. They aren't even designed for 2G turns. That's my point. Nobody is making sharp turns in airliners anyway. Routes are determined with weather accounted for in advance, and if a diversion around unplanned weather mid-flight is needed, airliners make long, sweeping turns to avoid it already.
LargoLasskhyfv 5y ago
They go higher than normal passenger jets. Thus they could glide longer, because they'd start from an altitude of anywhere between 13 to 16 kilometers up, maybe even 20km. There is almost no weather to speak of there, and if so it wouldn't require a sharp turn, because anything reaching up there would be visible from far away. (like a thunderstorm) That's the whole point of so called high-altitude/high-atmospheric platforms as an alternative to low orbiting satellites. (Think stationary blimp with many antennae/transponder on its belly for internet, or something) What are you smoking!?
stouset 5y ago
Also, you might want to actually read the Wikipedia article you linked. There have been ten total cases of structural failure in the past twenty years of aviation. Two of those involved spacecraft (Space Shuttle Columbia and VSS Enterprise). One of them was a terrorist bombing (Metrojet 9268). One was a fighter jet (F-15). So six left. In all of those six, there were essentially 100% casualties. So how exactly would a supersonic jet be "worse"?

by blunte 5y ago

stouset 5y ago

> The faster you are traveling (which really matters as a factor of the drag you are experiencing), the more serious any event is which changes the shape of your vehicle. Even non structural failures, such as an engine cowling coming off mid-flight can strike other parts of the aircraft, resulting in damage and changes to the structure. Yes, an engine falling off will be more impactful to a plane traveling at supersonic speeds. But these types of incidents are an extremely minor fraction of overall failures, and particularly during cruise at altitude (e.g., when the risk of bird strikes is minimal). Engineering steps can be taken to minimize risks like this further since the consequences of failure are higher. > Commercial aircraft are just impractical to operate safely at such high speeds. This argument was made when the first jetliners were being rolled out too. It carries about as much weight now as it did then. > Faster, heavier aircraft need longer runways to land. That limits your alternate landing choices. Diversions may cost you more fuel since they may be much greater distances away. This hasn't stopped faster, heavier aircraft from becoming commercial successes so far. A diversion is already extremely expensive for a myriad of reasons. Schedules, aircrew, and sometimes planes have to be shuffled around. Stranded passengers often need accommodation and/or alternative transport arranged. Airfare credits are often handed out. Incurring slightly higher fuel costs from having to divert a bit farther is just not that significant of a factor here, and one that is easily compensated for by adjusting ticket prices. Bumping the cost of an uncommon, already-expensive event by a few percentage points just doesn't move the needle much. > And you cannot simply make a "sharp turn" at high speed. Your passengers (and the airframe on a large craft) are not prepared for 4G turns. They aren't even designed for 2G turns. That's my point. Nobody is making sharp turns in airliners anyway. Routes are determined with weather accounted for in advance, and if a diversion around unplanned weather mid-flight is needed, airliners make long, sweeping turns to avoid it already.

LargoLasskhyfv 5y ago

They go higher than normal passenger jets. Thus they could glide longer, because they'd start from an altitude of anywhere between 13 to 16 kilometers up, maybe even 20km. There is almost no weather to speak of there, and if so it wouldn't require a sharp turn, because anything reaching up there would be visible from far away. (like a thunderstorm) That's the whole point of so called high-altitude/high-atmospheric platforms as an alternative to low orbiting satellites. (Think stationary blimp with many antennae/transponder on its belly for internet, or something) What are you smoking!?

stouset 5y ago

Also, you might want to actually read the Wikipedia article you linked. There have been ten total cases of structural failure in the past twenty years of aviation. Two of those involved spacecraft (Space Shuttle Columbia and VSS Enterprise). One of them was a terrorist bombing (Metrojet 9268). One was a fighter jet (F-15). So six left. In all of those six, there were essentially 100% casualties. So how exactly would a supersonic jet be "worse"?