Rolls-Royce Liftjets from RB82 to XJ-99

[alertken]

I do not see a distinctive asset of team spirit to explain the business outcome of P.1127/VT vs. Balzac/liftjets. A felicitous "community" is just as central to any project's technical and business success as it is, say, in a marriage. The Hawker and Bristol Aero-Engines' Project Teams had a shared investment in the VT concept, just as Griffith's liftjet was embraced by RR, as policy, and by Short's, Dassault and the German teams. That NBMR.3 was "won" by VT and RAF's spinoff from NBMR.4 by liftjets, was not due to engineers' teamwork...alone. As with a marriage, harmony must be presumed: RR, I daresay, will have put just as much corporate heft into teamwork with AMD (RB162/Mirage IIIV), EWR (RB145+153+162/VJ101s), HSAL (Medway+RB162/HS681), as (to be) BSEL did with HSAL (Pegasus/P.1127+HS681; BS.100/P.1154), Dornier (Pegasus/Do.31).

Directors' commitment of funds ahead of a customer was, indeed, "a highly unusual state of affairs in the aircraft industry", c. 1958. Sir Arnold Hall did that, not in community with his VT Project Team, but to preserve his firm's credibility as a contract partner: FRG selected NBMR.1, G-91R, 3/59, with licenced Orpheus, core of BE.53 (to be Pegasus).

Pegasus was on HS.681 right up to ITP (a model at SBAC Show, 9/1963, had the nacelles covered up: RB142 was substituted for BS.53 during the Show). RAF had no interest in P.1127 before 2/65 and little, ever, in NBMR.3 due to complexity - operational and industrial: life was fraught already with, say, reheated Avon/Lightning from the home industry, so to add unproven power+distant foreigners would have been odd. RAF settled for P.1154/BS.100, 2/63, only after Ministers despaired of France accepting it as NBMR.3 winner-in-collaboration.

The downsides of the liftjet concept were dead weight in every operational phase bar TOL, and the cost of putting longevity into expendable GW power. Just like the weight of a fat VT fan and the cost/reliability of its hot swivelling nozzles. That's why V/STOL became a maritime asset, except only the very Forward Edge of the (N.German) Battlefield. F-5E/G-91R/Alphajet/Lansen off-autobahns dispensed with runways. VT was not inherently superior to liftjet, nor was the Bristol+Hawker community "better" than say, that ultimate V/STOL device, EWR/Fairchild AVS. Harriers became, after much evolution, operable in specific roles at costs some Users could swallow. No liftjet type has done so, but not, I suggest, due to poor community of their Project Teams.

 

[Barrington Bond]

 

[tartle]

Alertkin,
I was wondering what reaction there might be to their views....... There is an underlying thread in the whole paper that sticking to one's technological solution 'guns' is a bad thing if the result is not successful but good if it is. I think your comments underline the difficulties of hindsight. It was not obvious how the scenarios for these aircraft were going to develop and it was good that we investigated the alternatives. Whilst Shorts were sticking to one solution, working together with with RR , and therefore finding out what were the challenges ... these informed the Bristol/Hawker approach, especially on control.
As to the G.91 etc off-autobahn solution.. it is interesting to consider how much Harrier was used in a STO mode rather than VTO... anyone know the answer.
As you rightly point out ... going ahead with the contract in spite of bidding too low would have been a commercial credibility decision perhaps in the knowledge that there was a good team that would keep costs under control on this project.. the lack of interest from RAF may have been an asset as it enabled the spec to remain intact for longer!

 

[tartle]

BB.. great material... thanks for sharing.
your second dwg ties in with picture of hardware here

 

[alertken]

My understanding is that RAF, 1/65, wanted the entire P.1154 budget assigned to 175 F-4D, after Defence Scientific Advisor Zuckerman lodged his judgement that it was "a technological and economic impossibility” SZ,Monkeys Men & Missiles, Collins, 88, P.383. The notion of jumping in the heat of NEAF/FEAF was risible, and was pointless for 38 Gp. off West Raynham's ample strip. It could only have some purpose in RAFG, but payload would a trade for verticality. Minister of Aviation Jenkins, with an industry sponsor role, put forward P.1127(RAF) to salvage something from the detritus of P.1154/HS681/imminent TSR.2. CAS chose not to argue, to accept what Ministers were minded to buy, with his priority on dumping TSR.2 for F-111K. He invented a Mission for a baseful of jumpers: encopsed before very forward RAF Gütersloh was lost, incendiary hops would delete Sov. POL dumps; like Guderian in the Bulge, Red armour would splutter. Iron first sortie by RAFG, WE.177A second, from Wittering-based Sqdns. The type had puff enough for that job. 175 F-4M became 116 F-4M + (6 DB+) 60 (to be) Harrier GR.1.

The process (F-111K - AFVG - UKVG - MRCA) which replaced RAFG Canberra also threw up Jaguar S, which had payload and range and autobahn-compatibility. Harriers evolved some payload, retained the iron role of disruption-from-dispersed hides, but passed the nuke sortie to F-4M, then Jaguar, then Tornado.

 

[JFC Fuller]

I am well versed in the relationship between the P.1154, Phantom, Jaguar and then Tornado (although the latter does so much more and is far more important- in my opinion).

Zuckerman follows up his opinions of the P.1154 with a series of quotes from the Crossman diaries (which I must get my hands on), the most interesting phrase, in reference to P.1127, being as follows:

"...Cabinet agreed that the cancellation would not take place and that it was still an extra outside the defence budget."

In short, if this is true, P.1127 was procured for the RAF out of extraordinary funds rather than from the core defence budget, that would go some way to explaining the increase in the number of squadrons that the procurement of the type caused. The services were hardly going to argue against something they did not even have to pay for. Of course, the obvious question then becomes why it was felt so important to keep the aircraft alive; I suspect a combination of factors, firstly it acted as cover for the mass cancellations of the big projects (look, British industry is still doing something!) and there was still US interest. They had part-funded it in the first place through MWDP; I have a note saying 75% of Pegasus development came through MWDP with Bristol providing the other 25% (same arrangement as Orpheus), P.1127 must have been cheap. Harrier must have been even cheaper; the nav-attack system (Ferranti INAS) was a derivative of the one being used in the Phantom and the airframe was an improved version of the already flying P.1127, it was basically all sunk cost, and some of it not even British sunk cost. According to Saki Dockrill (Britain's Retreat from East of Suez) the cancellation of P.1127 would have yielded a £35 million saving in 1966 and the purchase of 110 P.1127s would have cost an additional £300 million over 10 years.

For Phantoms, my understanding was that the original order was for 150 (almost a one-for-one replacement for the P.1154) but that the final 32 were cancelled and 20 of the reduced RN order diverted to the RAF resulting in 7 rather than 8 RAF squadrons being sustained. However, prior to that Dockrill has a suggestion of 205 Phantoms, 150 plus a further 55 replacing a planned 110 P.1127s.

 

[tartle]

Fascinating stuff gentlemen!
As an apprentice, one of my assignments was in the Phantom Spey Development Office and I remember seeing trade-offs between performance and cost going on to see what could be sacrificed on the first Spey Phantoms in order to get the unit cost down... subsequent developments would hopefully restore some of the losses. Must see what is about on this subject.

 

[LowObservable]

Interesting stuff...

My recollection and study of the P.1127 and its descendants was that - from the earliest tests of STO modes in late 1961 - the ability to perform a simple and effective STO was the discriminator over other V/STOL designs.

A few points:

At the time, no VTO could be designed with acceptable warload/range.

Not only was the T/O run short but the liftoff speed was low, so relatively uneven surfaces were acceptable.

Landing distances were seen as a bigger limiting factor than T/O distances. (Sweden was regarded as the source of funny looking cars, trendy furniture and blonde au pairs.)

VT meant no faffing around with starting/stopping/throttling lift jets in the take-off - just a stop on the nozzle control. LPLC designs have a lot of intake momentum drag that's can't be offset by full-aft vectoring. (Look at an F-35B, taking off with a giant airbrake behind the cockpit.)

Reality today is a different story. The Marines are talking about 3000-foot "austere" strips - it's not certain how that relates to F-35B performance (since the land STO run KPP has not been released, if indeed there is one), or whether it's for KC-130 support. If anyone knows of an affordable supersonic fighter that can operate all day long from 800 meters, maybe they could give the Commandant a call...

 

[alertken]

SLL, 18/3: I doubt there was ever a CAS Plan for 110, or any other number, of P.1127s, before Roy Jenkins salvaged 60 (plus 6 DB) from the detritus of P.1154, 2/65.

2xP.1127 were taken on, 22/6/60, in MoA's Aircraft Research budget. This was a modest, RAE backwater where orphans lingered - Hunting Jet Flap, SC.1, Marshall MA.4 and Cranfield/HP sucker aerofoils. NBMR.3, supersonic, was initiated 8/61 and was won by P.1154 by late-62...except in France. By then Ministers had judged that Hunter FGA.9/FR.10 and Sea Vixen FAW.2 should both be replaced by a common airframe (though with 1 and 2 seat variants) combining supersonic dash and (V-)STOL. At no point between 6/60 and 1/63 did RAF evince any more interest in P.1127 than they did in MoA/AR's other toys. P.1154 was funded 18/2/63 (BS.100 defeating swivelling Twin Spey, 25/3/63). To demonstrate that V/STOL was the right way for Central Front, Forward Edge of the Battle Area mud-moving, Tripartite Kestrel Evaluation Squadron was funded 11/1/63, operating with 9 a/c, 1/4/65 - 30/11/65: but note who was in it. A small RAF contingent (and it was based on RAF W.Raynham), but: no RN, no USMC, no USN. Luftwaffe, US Army and USAF were there - none of whom pursued the V/STOL notion. US and FRG took their share of the kit away, and did next to nothing with them. What they wanted, was what RAF wanted: F-4s in profusion, because that type offered all the payload, over all the range anyone could use. From a runway. So NATO chose to ignore Scuds targetting every Euro-strip, and to assume an iron interlude from immortal concrete. And then the tactical nuke exchange, deeper and with heavier load than any Stoltype could haul.

We cannot de/re-construct these procurement decisions in isolation from the perceptions of the time, that nukes would, or maybe not, be used early, later or not at all. Harriers before about GR.7 could only payback their cost if they delivered one WE177A close and quick. Only a few armour blockers would be risked on iron because most must be preserved for that nuke sortie. So one iron Wing, 24 a/c, on Gutersloh, plus one nuke Wing sallying forth from Wittering, 24 a/c, was all we needed.

 

[tartle]

This lecture by John Farley fleshes out the essence of what I have posted on the Pegasus genesis... really good overview of Harrier history! Read the lecture to see the first solution to Ralp Hooper's problem.

 

[tartle]

The XJ99 was built in 2 versions one with a toroidal combustion chamber and one with a 'conventional annular combustion chamber.
To help think what the toroidal chmaber might have been consider the circular gas flow that 'sits' downstream of a fuel nozzle.. then consider half the flow pattern ... lower half say of a picture like fig 2 in this paper . In the upper diagram of this fig cut off the diagram about a fifth of the way from left and think of that as the chamber and presto we have something like the XJ99?

 

[alertken]

(T: on the Hyper/problems thread, you: found the first performance calcs that I did ...on an Allison lift jet years prior to the XJ-99 collaboration). Any more in depths of brain/tea-chest? My memory from MoA's initial funding of XJ99 was of liftjets being seen as a one-way flow of info, Allison seen as recipient, not real, originating collaborator. Work was only in part to produce a dead-weight VTO device, and just as interesting was lightweight-but-resilient components, to be fed into any engine. That's why funding endured awhile after early-1968 chop of EWR AVS.

 

[tartle]

Allison was a recipient of funding from the USAF continuing Technology Program. The first to be built was the 610-A1 gas generator core followed by the -D1 lift fan and then the -B5 direct lift turbojet. The lack of a V/STOL aircraft project meant work switched to the B5 early on and only started again in support of XJ99 joint program(me) mid-66. The fan engine was designed to achieve 10,000lbt at 20:1 T/W and a BPR=2.5 giving sfc of 0.634.
The B5 was a lower thrust pure jet, weighing in at 21/1 T/W, feeding into a design for a lift engine for the US/German joint strike V/STOL fighter.
Note the wiring on the very long turbine blades that drive the fan.. or could be clappers; these will be to alter the natural vibration frequencies.

 

[Johnbr]

Very good post.

 

[alertken]

Thank you, again. all new to me.

 

[starviking]

To help think what the toroidal chmaber might have been consider the circular gas flow that 'sits' downstream of a fuel nozzle.. then consider half the flow pattern ... lower half say of a picture like fig 2 in this paper .

Would I be correct in saying that the flow would be like a stationary, continually replenished smoke ring (in reverse?)

 

[tartle]

That's a good way of describing it!

 

[starviking]

That's a good way of describing it!

Cheers!

 

[tartle]

The RAF Historical society published this on the Harrier ...pages 14-38 give insights into the development of the engine and also a comparison of P1127 and SC1 vertical flight ch'ics.
The evolution of the Pegasus was encapsulated in diagram below.

 

[tartle]

Another rival project for the RB108 experimental test aircraft (that resulted in the Short SC.1) was a version of the Avro 707B... see below

 

[lancer21]

Gentlemen,

Hope this is not too off topic. I found some fascinating info both here on SP and on the net about the history of 3BSN developments, and found this image of a RB.153 mock-up with a 3BSN earlier in this topic:

http://www.secretprojects.co.uk/forum/index.php?action=dlattach;topic=2069.0;attach=149206;image

Now do any of you gents know when and where was the image taken, and was it a public image at the time? Is this version called RB.153-76A?

And on a more general note, i was trying to find out who really invented the 3BSN as we know it in the first place, i am familiar with the Lockheed claims (they don't mention british or german work on the subject), but upon some google searching i found this from Flateric:

F-35В и опыт Як-141 - использован ли? [Форумы Balancer.Ru]

..и если да, то как и насколько: Встречаются утверждения, что в F-35В довольно много от Як-141 и его проектных наследников - причём якобы не просто вследствие заимствования неких общих решений, а по…

forums.airbase.ru

Any additional details would be greatly appreciated, thank you.

 

[Mike Pryce]

From "Jet V/STOL propulsion systems of the 20th century", Hirschberg, Michael J.; Pryce, Michael J.; Müller, Thomas.

Annual Forum Proceedings - AHS International|Annual Forum Proc. AHS Int.. Vol. 3 Alexandria, Virginia, USA : American Helicopter Society International, 2011. p. 1784-1813.

RB.153-76A Lift/Cruise Engine
The engines for the VJ 101E were planned to be the RB.153-76A, an 8,480 lb (37.7 kN) version of the RB.153-61, capable of 14,790 lb (65.8 kN) thrust in afterburner. Thrust increase was through 25% more airflow. The engines were to vector the thrust from horizontal to vertical via three-bearing swivel nozzles, called a Schwenknachbrenner (SNB) or “swiveling afterburner”.

Figure 57. RB.153-76A lift/cruise engine
Despite the lack of funding for the VJ 101E concept, a contract was received from the BMVg for development of the nozzle in 1964. One-quarter scale cold and hot models were tested to solve the cooling and pressure challenges. A half-scale actuatable nozzle and a full scale fixed nozzle were also built, but funding was halted just prior to testing in mid-1966.

Figure 41. Half-scale actuatable SNB nozzle
A joint US-German agreement was consummated in December 1964 to begin preliminary work for the joint development of an Advanced V/STOL Strike (AVS) weapons system. With some funding from General Electric, the capability to deflect afterburning flow in the swivel nozzles was substantiated by MAN for AVS in full-scale demonstrator engine tests performed in September 1967 on an RB.153-61.
Run time on the nozzle was 29 hours; tests were conducted in afterburner for 2.5 hrs at the full deflection angle (90°), as well as similar time at 0° and 45°. Although some small cracks were found in the overlapping flaps at the liner segment joints, the tests did provide an initial substantiation of the first nozzle capable of providing afterburning thrust in lift and cruise.

 

[charleybarley]

And on a more general note, i was trying to find out who really invented the 3BSN as we know it ?

How about Jack Britt, Rolls-Royce? (patent filed June 1954) U.S. Patent 2,933,891, "Jet pipe arrangements for jet propulsion engines". He even has an arrangement for reversing thrust. http://www.google.com/patents/US2933891

There is also a drawing of a 3BSN, Fig 21-8, in "The Jet Engine" RR Limited, 3rd edition dated July 1969.

And, filed May 1967, a P&W cooling scheme for an afterburner 3BSN. http://www.google.com/patents/US3429509

The first to fly? Perhaps this is a 3BSN on the YAK38 http://scalemodels.ru/modules/photo/viewcat.php?id=4223&cid=170&min=60&orderby=dateA&show=12

 

[sferrin]

And on a more general note, i was trying to find out who really invented the 3BSN as we know it ?

How about Jack Britt, Rolls-Royce? (patent filed June 1954) U.S. Patent 2,933,891, "Jet pipe arrangements for jet propulsion engines". He even has an arrangement for reversing thrust. http://www.google.com/patents/US2933891

IIRC this one was also before US efforts:

 

[tbritt]

And on a more general note, i was trying to find out who really invented the 3BSN as we know it ?

How about Jack Britt, Rolls-Royce? (patent filed June 1954) U.S. Patent 2,933,891, "Jet pipe arrangements for jet propulsion engines". He even has an arrangement for reversing thrust. http://www.google.com/patents/US2933891

IIRC this one was also before US efforts:

Jack Britt is my Grandfather. He died in 2005 and I don't know very much about his career at RR, however, my father always told me he "invented" this engine

 

[Archibald]

Google books shows that "the XJ99 made early test runs in 1969"

"allison""XJ99" - Recherche Google

 

[alertken]

I have XJ99/Allison/M.A.N/RR ITP 10/65, bench test 7/68 (though its intended application, Fairchild/EWR AVS was canx 1/68), continuing on dribble Research funds into 1971 as composite/lightweight components demonstrator, so feeding into (to be RB199/Tornado).

 

[TsrJoe]

RB.162, 'Aeroventure', South Yorkshire Aircraft Museum, Doncaster, 2022