VTOL double-delta "Drakens"

[steelpillow]

Hawker's P.1126 project is said to have been a VTOL fighter looking much like the Saab Draken. But very little seems to be published about it.

Tony Buttler; British Secret Projects 2: Jet Bombers Since 1949, Crecy, 2018. Chapter 10 references the P.1126 - can anybody summarise what he has to say?

Mike Pryce's defunct harrier.org.uk website is (mostly?) preserved by the Wayback Machine and notes:

P.1126​

Multiple lift engine VTOL strike aircraft​

2 x Bristol Orpheus and 12 x RB.108​

1957​

Resembled SAAB Draken with horizontally retracted lift jets​

It also has this drawing to offer:


I am sure I have seen similar images published elsewhere, without their origins being credited.
Can anybody provide any further information/sources?

 

[iverson]

Hawker's P.1126 project is said to have been a VTOL fighter looking much like the Saab Draken. But very little seems to be published about it.

Tony Buttler; British Secret Projects 2: Jet Bombers Since 1949, Crecy, 2018. Chapter 10 references the P.1126 - can anybody summarise what he has to say?

Mike Pryce's defunct harrier.org.uk website is (mostly?) preserved by the Wayback Machine and notes:

P.1126​

Multiple lift engine VTOL strike aircraft​

2 x Bristol Orpheus and 12 x RB.108​

1957​

Resembled SAAB Draken with horizontally retracted lift jets​

It also has this drawing to offer:


I am sure I have seen similar images published elsewhere, without their origins being credited.
Can anybody provide any further information/sources?

I've seen a model of this somewhere. As far as I recall, it was said to be a Rolls-Royce study.

 

[overscan (PaulMM)]

Source:

Mike Pryce - Beyond the Harrier - Kingston V/Stol Projects 1957-1988

SAE MOBILUS

The drawing is credited to "General Arrangements collection" at Brooklands.

Considering its longevity, it is perhaps surprising that Ralph Hooper’s P1127 was the first V/STOL design undertaken at Kingston. The second project was Ron Williams’ P1126 (the number had been booked first, but design work began later), [73] a VTOL strike fighter that resembled the SAAB Draken.

Figure 1. P1126. Note use of landing skids [26]

The P1126 had six lift jets lying horizontally in each inner wing that hinged downwards for vertical flight. Two Bristol Orpheus propulsion engines were used for forward flight. This project was the precursor of a considerable number of multiple engine schemes studied by Ron Williams and John Fozard, with project numbers in the P1136-P1149 range. [26, 65, 66] The majority of these utilised a combination of dedicated lift engines (RB.153 or RB.162) in addition to others used for both lift and cruise propulsion, the latter either fuselage-mounted or in tilting wingtip pods (conceptually these designs were similar to the contemporary German VJ 101C and the later Soviet Yak-38). These designs could be very complicated; for example the P1137 had two aft-mounted lift/propulsion engines, a further pair in swivelling wing-tip nacelles and three lift engines in the forward fuselage. A high degree of automation would have been required to control such an aircraft.

I'd suggest Chris Ferrara at Brooklands would be worth contacting.

My feeling is this was a counterstudy or baseline to P.1127 using a "conventional" approach rather than a serious design.

 

[steelpillow]

I am sure I have seen similar images published elsewhere, without their origins being credited.
Can anybody provide any further information/sources?

I've seen a model of this somewhere. As far as I recall, it was said to be a Rolls-Royce study.

Aha, jogged my memory. It's the R-R one I remembered seeing but forgot whose it was. It seems to postdate the Hawker one, appearing at Farnborough in 1961. Note the differing arrangement of fewer more powerful lift engines, and only a single thrust engine:

 

[steelpillow]

Here is a translation of the relevant text from the Les Ailes report on Farnborough 1961, per the image in my previous post. Not overly informative, but some interesting context. My bold:

"...the small RB.145, intended for propulsion as well as lift, and which already gives 1,250 kg of thrust for a weight of 138 kg (reheat is planned); a coupling of two RB.108 (21,130 kgp), with retractable bladed grid contrilling the flow in vertical and oblique flight; the model of a steerable jet deflector is also exhibited, as well as several models of vertical take-off aircraft: two of them schematize what could be conventional transport planes equipped with two fairings with 10 and 16 vertical engines, authorizing vertical take-off; a third represents a V.T.O.L. with 4 vertical engines and 1 horizontal bypass turbofan (SC.1 solution); the fourth model, 6 surprise, represents a swept-wing V.T.O.L. equipped with two groups of two vertical engines and two horizontal engines equipped with jet deflectors: this mixed solution makes it possible to reduce the importance of the vertical engines, and therefore represents a compromise between the SC.1 and the P .1127... Rolls-Royce also confirms the work carried out on the RB.162 lift jet (thrust/weight ratio of around 16) on behalf of the Germans and the French."

 

[iverson]

The Rolls example looks a little more practical than the Hawker. How would transition have worked in the latter?

 

[steelpillow]

The Rolls example looks a little more practical than the Hawker. How would transition have worked in the latter?

Much the same way. Lift engines to take off, then fire up the thrust engines and progressively throttle back the lift engines until flying normally, then retract the lift engines sideways just like wheeled undercarriage. Note the T-shaped slots in the wing to accept the skids fixed to the engine doors. But it is not clear how the lift engine intakes would have been supposed to work; narrower longitudinal doors in the upper wing surface, perhaps.
The Rolls is single-engined for thrust and has much the same Avon as the Draken. The Hawker has twin Bristol Orpheus, again giving roughly the same max thrust in total (This suggests Hawker might have had the Navy in mind, as they tend to prefer twin engines and minimal takeoff runs). So all three are likely to be comparable in size, with the Hawker one a bit bigger and heavier than the Draken and with reduced performance, thanks to carrying its lift engines around. The Rolls one benefits from several more years of lift engine development, hence a neater installation which puts it somewhere between the other two. The cockpit canopy proportions for the three types look reasonably consistent with that.

 

[steelpillow]

Here's another British VTOL Draken, this one from Short Bros. This composite clipping is from Flight, 16 Dec 1960, p.944. Does anybody know anything more about it, such as its designation?

 

[steelpillow]

The Sud Aviation X-600 grew Draken-like as it progressed, and spawned the externally similar X-601, discussed at https://www.secretprojects.co.uk/threads/sud-aviation-x600-vtol.14633/
Here is a taster from it:

 

[Maveric]

A great drawing by a great draughtsman.

 

[steelpillow]

Are the Rolls-Royce and Sud designs in fact the same project?
The French translation above notes that "Rolls-Royce also confirms the work carried out on the RB.162 lift jet (thrust/weight ratio of around 16) on behalf of the Germans and the French."
The clipping below says that "Four in-line RB.162s provide lift thrust for V/STOL fighter under development by Sud-Dassault consortium."


The next clipping gives the engine rating as 6,000 lb:


The RB. 162 was rated around 5,000 lb and a production version might well have reached 6,000 lb.

So on the face of it, RR were developing the RB.162 on behalf of Sud/Dassault, with a view to dropping four of them into a Franco-German VTOL fighter. The RR concept and the SA X-600 are much the same size, with both in the 20-24,000 lb MTOW class.

But the X-600 did not use the four-in-line layout. Might the RR concept actually be the X-601? Or were Sud working on two closely similar projects at once? Was a journalist misled somewhere? Or what?

There is an article on Sud's fighter projects, including the X-600, in le Fana de l'Aviation, No. 492, Novembre 2010.
Our Jean-Christophe Carbonel also covers the X-600 and -601 in his French Secret Projects vol. 1.
Does either shed any light on all this?