interesting on wiki - clearly at 113db it was insanely loud, but they seemed on track to hit 95db at 200ft - which is massively quieter.

at these lower levels, was it still to be a dead duck?

PS is it right that a single pegasus engine failure (not unheard of in the harrier), would have been catastrophic in any non-conventional flight modes of the Do-31, and maybe in any regime? Did it ever fly with someone not in an ejector seat?

Hmm - maybe. I suppose whoever's in possession of the design could license it to an enterprising Chinese aerospace company to see if they could make anything of it.

dead_ pan

To get on the wheel you had to fly (or at least try).

Re the killer app, have a look for the Flight article to which I referred. The Eurocopter head was talking about large capacity VTOL flying short-haul routes as an alternative to building additional runway capacity, with all its associated costs and timeframes.

JF - you've lost me there.

V/STOL Wheel
 

According to the website:

So stillborn projects such as the Br.1030 do not appear on the Wheel.

Ahh okay.

I suppose that Heath-Robinson-esque contraption recently built and flown by the Australian husband-and-wife team doesn't really count, as it is not an 'official' project. According to the NASA Dryden web site, the X-wing did fly but without the rotor attached.

The Do-31? I see it as the rich man's Osprey.

New video.

It's actually quite a good looking aircraft, with shades of Flash Gordon's War Rocket Ajax in its appearance (google it). The flexing of the wings on landing was impressive, and makes you wonder at what point the engine pods would come off.

The question I have is with regard to later Pegasus variants, which could have substituted the RB162 batteries and turned the Do 31 into a four Pegasus design, making it even more useful by not having to cart around the batteries when they were not doing anything useful. Four Mk.103s would have given over 80,000lb of thrust, as opposed to the Pegasus 5/RB162 combination as used, which gave a combined 66,000lb.

Buried in that original link was this...kind of looks familiar!

https://en.wikipedia.org/wiki/VFW_VAK_191B

What about the DO 29? I always thought it was great.

https://en.wikipedia.org/wiki/Dornier_Do_29

Couple o' issues here.

First, this would be horribly inefficient compared to alternatives. Compromises acceptable in a fighter/attack vehicle won't do for a transport, which is what Do-31 kind of was. If FVL-Heavy or Ultra comes about, a large Tilt-Rotor would meet the cargo craft need much easier.

Second, any engine power loss would result in an instant and uncontrollable roll unless there was a very fast acting system to reduce power on the other side which would allow you to crash inn a level attitude instead. On VTOL jets that have more than one lift source (Yak-38, F-35B, etc.) if one of the lift sources goes down, the aircraft autoejects you almost instantly. Not a viable option in this type of craft.