I don't think that dragonfly like wings could be structurally strong enough to support a human size being in flight. The largest prehistoric dragonflies weren't nearly as large as a human.
I think I remember that it was calculated that humans should be able to fly with artificial wings on Titan due to the low gravity and dense atmosphere. Because of the ...
Its not unplausable, however there needs to be a reason for the creature not flying again.
Animals are very much living creatures, and all things equal - being alive tops being dead.
Also if these creatures have general intelligence there will be a learning period, this is often provided for by the parent/herd/pack. In the absence of the mother these ...
To calculate it, you need to choose a wing-loading factor:
Wing loading for birds is generally between 1 to 20 kg/m2. The maximum possible wing load before a bird is unable to fly is about 25 kg/m2. This is when the bird is too heavy for its wings (like the kiwi, which has tiny wings and a large body mass).
So 1638 lbs is c.a. 743kg. That means:
with a ...
In order to have a large flying hexapod, you might want to consider adding:
Flaps between limbs
A habitat near some form of updraft - ocean winds, volcanic wind, or some manufactured thing.
Honeycombed bones; an organ to create hydrogen
An incredibly large diet; perhaps hibernation when this isn't possible
One thing that could explain large size is a decent Ozone Layer, I saw something about a guy who grew a giant piranha using nothing more than having additional Ozone in the micro-ecosystem he created for it...
If gravity was 1.5 times stronger, a flying creature would need 1.5 times the lift to fly. This could be achieved by flying faster or flying through denser air, but either flying faster or flying through denser air would increase drag. The net effect is 1.5 times gravity requires 1.5 times the power to fly.
Given the limits seen in large flying creatures on ...