[DebtDeflation]

I've been following the story and this has been discussed on the local Reddit subs. They are almost certainly PteroDynamics XP-4 drones flying from and to the military bases in question for testing purposes. There literally was a public demo of them on the USNS Burlington in Philadelphia a year ago.

[senkora]

Video of that model of drone: https://www.reddit.com/r/EngineeringPorn/comments/13juxdi/pt...

[VectorLock]

https://www.youtube.com/watch?v=kA1ENhxLqTo

[bloopernova]

I really like that it switches off the outer pair of propellers in level flight, that's a nice feature.

Changing the vertical alignment of the wings to horizontal after takeoff is also really cool, an interesting alternative to 4 vertical propellers with a separate pair of wings. It seems to eliminate the extra moving parts to control those vertical propellers.

[VectorLock]

The linkage system is pretty cool I will say that.

[topspin]

Something actually patent-worthy.

[fer]

How? it's just a UAV, quad version of a V-22 Osprey. Maybe I'm missing something peculiar about it?

https://en.wikipedia.org/wiki/Bell_Boeing_V-22_Osprey

[matsemann]

"just" is doing a lot of work there. Everything is "just" an evolution of something else. Doesn't mean it's not novel or clever.

[rtkwe]

The wing folding mechanism is pretty novel as far as I'm aware. The idea of quad hover to forward flight isn't new or unique but the specific configuration is something I haven't seen before. NASA was working on some that tilted the whole wing not this folding design which uses fewer motors compare to the old NASA Greased Lightning test article.

https://www.youtube.com/watch?v=kXql26sF5uc

[topspin]

Osprey has a common power shaft between the engines for fault tolerance, constraining the structure's design, such as the lack of dihedral. This has a different set of design constraints and a different solution to propulsion failure.

[throwaway48476]

The hinge mechanism and the control dynamics.

[selfmodruntime]

HN is yet again amazed that military technology is in fact used to carry out secret operations.