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Old 5th Aug 2019, 17:59
  #121 (permalink)  
pattern_is_full
 
Join Date: Jan 2008
Location: Denver
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Originally Posted by Less Hair
The main problem for battery powered aircraft I see is their weight. Especially on landing. An empty battery is as heavy as a fully loaded one. That's like every landing will be a heavy landing. Combine that with short endurance and many short flights and you have a high structural fatigue and you will need more robust structure.
Yes, but at what point does landing weight become a special factor? I.E. must be a value less than MTOW, and so-listed in the manual? And assumed by the engineers? And does that include any aircraft likely to be electrified any time soon?

If a given design has a MLW of 5000kg, it can land at 5000kg. That is the spec, and it can be landed that way on every landing. There's nothing in the books that says "MLW - but only use this 10% of the time!"

And it doesn't matter how that weight is divided between structure, engines, batteries/fuel, and payload. Payload being the factor where adjustments are most easily made.

The difference between MTOW and MLW for a Twin Otter is 200lb/90Kg. Leave out one seat = end of problem.

Of course, that doesn't contradict the general idea that weight is always a critical problem in any aircraft, from balloons to A380s. And that electric flight beyond a certain point will depend on "unrealized" technology, like the ability to make aluminum engine blocks in place of cast-iron was for aviation 116 years ago.

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