Royal Navy Shorts Stingray S.1

[CammNut]

Meet the Shorts PD.13, loser to the Blackburn B.103 Buccaneer in the competition for the Royal Navy's NA.39 requirement for a carrier-based strike aircraft.


Compared with the Buccaneer, the PD.13 was an unconventional design, a tailless aircraft with a highly swept "aero-isoclinic" wing and thrust vectoring. 


An aero-isoclinic wing is a swept wing designed to maintain constant incidence as it flexes under aerodynamic loads, incidence being the built-in angle between the wing chord line and the aircraft longitudinal axis. In an aero-isoclinic wing, the change of incidence due to twisting of the wing is neutralised by that produced by wing bending.

Thin swept wings of the time were prone to aileron reversal, tip stall and flutter as aerodynamic loads caused the structure to bend and twist. The aero-isoclinic wing was designed to avoid this by locating the torsion box well back so that the loads would act to stabilize the wing.


In Shorts' design, the wingtips pivoted up and down, functioning as elevons for stability and control in the absence of a horizontal tail, which reduced weight and drag. The concept was developed by Geoffrey Hill and tested on the Short SB.1 unpowered glider and powered SB.4.

Designed to meet naval staff requirement NA.39 for a long-range carrier-based strike aircraft, the PD.13 was to be powered by a pair of Rolls-Royce Avons fitted with exhausts that could be deflected downwards to shorten takeoff and landing rolls.

A fighter-style cockpit was offset to the left while the navigator sat Sea Vixen-style in a "coal hole" under a hatch on the right side.



The PD.13 had an internal bomb bay, and fairings on the wing trailing edges housed the main landing gear. The aircraft sits quite nose-up in the ground, like a Vought Cutlass, and there is a small retractable tailwheel. I suspect the aircraft was to be pulled tail-down for launch from the RN's relatively short carrier flightdecks, as was the Buccaneer.

This is a 1/72 resin kit from Unicraft so you can imagine the...simplicity. But it is also unique and the shape looks about right based on the very few drawings available. The fuselage is in two halves but they are so thick that the finished model feels like solid resin. The surface finish is smooth enough but the panel lines are 'orrible. I could not be arsed to fix them. Instead I got my pencil out.


This is the first model where I used brass rods to pin the wings and tail. My drilling was a little imprecise, but the result is much improved robustness. I was also able to use brass rods to make the outer wing sections pivot so they could be posed. Which is just as well as a lot of sawing was involved separating the wing sections from their pour stubs and my sawing, like my drilling, is sloppy. The inner and outer wing sections were never going to meet precisely.


The left and engine nacelles are not the same length (which I did not correct). Neither were the left and right inlet ducts and I found myself taking an uncomfortably large drill to one of them. As for the exhausts, luckily I had brass tubing big enough to represent the nozzles. The engine nacelles are solid resin so I was not about to start hacking and hewing in a vain attempt to model the nozzles in their dropped, vectored position.

The cockpit is a rough-walled cave in the sandstone-textured resin that I left as an undetailed black hole, except for a floor, seat and panel. The landing gear is from the spares box, their lengths and locations guesstimated from the simplistic drawings available. (After taking pictures, I noticed one of the main gear doors fell off). I went for my favourite Buccaneer scheme, all-over dark grey. Markings are from various RN Buccaneer sheets.

[scooter]

Looks like something Britain's Batman would fly

[perttime]

Isn't that a little bit unusual     

[Leading Observer]

   Excellent work - I have considered buying the Unicraft model on more than one occasion, but Unicrafts reputation for being "difficult" to work with has always put me off. Maybe one of the current crop of 3D printing model makers will add this to the growing list of what ifs now available 

[Steel Penguin]

you've done a top job on that 
with the twist on the wing tips giving it a very " alive" look.

[PR19_Kit]

That's one SUPERB model of a very interesting aeroplane. 

And considering it was a Unicraft kit originally it's MIRACULOUS!

[The Rat]

Most excellent!   

[Accidental Loggie]

Lovely.  With that stance and AOA I can just imagine the steam from the catapult swirling around it immediately before launch.

[Thorvic]

Brave man trying to turn a unicraft kit into a presentable model, but you managed it and it looks good.

How does it look alongside a Buccaneer ?

[CammNut]

Thanks folks!

Here it is compared to the incomparable Buccaneer (AEW version)

[Thorvic]

Cheers, so a similar size then 

[buzzbomb]

Well that is a real gem. Terrific work

[Weaver]

That's excellent, especially starting from a Unicraft kit, which I've heard described as more a matter of sculpting than model-making.

The board that chose the B.103 (Buccaneer) were really impressed by the PD.13, but they thought the design was more appropriate for a mach 1.3 fighter than a subsonic strike aircraft, so they didn't think the technical risk was worth it for the requirement. The most impressive thing about the PD.13 was that it had an estimated roll rate of 720 deg/second!

[kerick]

That's an impressive piece of model building. Well done!

[McColm]

Well done