KRÅKAN - Push-Pull, Tandem Tilt-Rotor, VTOL Aircraft

Lol... It doesn't work. Push pull means that the front is pulling and the aft is... Pushing.
What then happens is that you have to go in reverse pitch with the rear engine that it can also deliver... Lift.
This means the transition can only happen while the speed is null.

There is a nearly similar solution but it's not that.

Edit:
My bad. Didn't pay attention to the thread location.
 
Might be practical with reconfigurable or morphing prop blades, say using dynamic composites (though God help you if you got hit with an EMP weapon).
 
I have had this solution on my desk for a few years. No misinterpretation of rear propeller thrust. But not without complications.
 
Wrong prop twist? Have you tried rotating backwards. ;);) (with 180 degree prop pitch control)

Do note the transition image shows asymmetric transition, so it wasn't unforeseen.
 
I think we should be glad the Rutans did not turn their gaze on such.

I can almost see a canard design with a nose prop and a w-i-d-e P-38-ish twin-boom layout, the tail rotor and engine mounted on the tail-plane so can tilt forwards...
Bwa-Ha-Ha-Haaa !!!
 
First reaction: No way! On second thought: Perhaps, but the complications seem at least equal to existing solutions. Nothing's insurmountable but I do have questions about managing the center and distribution of mass, moments, structural requirements and such.
 
Would not fly it. Not till someone demonstrated that my pea-brain understanding of aerodynamics and other magic associated with flying was incorrect.

Looks cool though; like something the Swedes would come up with.
 
Looks like something that should be tested on drones first... And I agree, the transition mode looks suspicious. One of propellers need to reverse rotation direction to transit from level flight to hovering.
 
Beyond the iffy transition, the air frame needs to support much of the vehicle weight in every direction. It is just a lot lighter to have lift devices at center of the vehicle or on the wings that is already build to hold up the vehicle.
 
The rear should be a jet engine that can be vectored downward. The shaft of that engine extends to the front, where it drives the tilt rotor at the front.

This is what the F-35B (STOVL) does. The jet engine can be vectored downward for VTOL, and the shaft of the engine extends forward to drive a lift fan.

It works.
 

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