Hawker Siddeley P.1154

Harrier was good for 100 plus passes on CBR6 and above surfaces without PSP. (For guidance;- CBR6 is approx the consistency where a normal weight person will not leave foot prints in the soil)

However PSP made sense for most operations and guarded against changes in weather conditions such as rain;- turning a CBR6 to 4 in minutes.

When any aircraft operates from unprepared surfaces FOD damage is unavoidable and expensive. During one very public drought relief operation using C130’s on unprepared surfaces the cost repairs due FOD (quietly paid by the tax payer) was nearly equal to the amount of money raised by the public charities. At the time it was largest charity fund raiser up until that that date.
 

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With regard to the status and viability of PCB at the time of the cancellation of the BS.100 and P.1154, Andrew Dow Pegasus: The Heart of the Harrier, states that PCB was never run on the BS.100 but was extensively rig tested on Pegasus test engines. The implication being that PCB worked in the sense that it generated thrust with an efficiency that was understood. However, that still leaves considerable scope for subsequent technical challenges had the programme continued with the oft referenced Hot Gas Reingestion (HGR) being an obvious one. One of the things tested in the early phases of the 1983-86 Shoeburyness PCB trials with the tethered Harrier test rig was the scaling rule developed in the 1960s to predict full scale HGR characteristics and it was found that the rule underestimated the effect on engines with augmented front nozzles. That does suggest that the P.1154 would have run into issues had it continued, whether they would have been insurmountable or not is far beyond my understanding.

Source: Proceedings of the 1985 NASA Ames Research Center's Ground-Effects Workshop

The current state-of-the-art in the U.K. on predicting full- scale HGR characteristics for STOVL aircraft from model
tests set up using scaling rules originally proposed twenty years ago can be summarised:

The rules give good model/full-scale agreement for both mean intake temperature rise and temperature distortion​
contours for STOVL aircraft, such as the P1127/Harrier, with cool front jets (circa 4OOK) and hot rear jets​
(950K) with no fountain control devices.​
​
Within limitations of current model/full-scale geometric similarity the rules appear to underpredict levels of​
mean temperature rise and temperature distortion from a 'test bed' type STOVL aircraft fitted with an augmented​
vectored thrust engine with front nozzle jet temperatures up to 1400K.​
​
Additional observations for the Tethered Harrier programme can be made:

The full-scale data produces a good collapse of mean intake temperature rise with simple front jet excess temperature supporting the 'old t rule.​
​
A greater discrepancy exists between full-scale and model predicted intake mean temperature rise than for​
temperature distortion.​
​
Intake temperature distortion contours at full-scale,although higher than model predictions, exhibit the same general​
shape.​

Accordingly it is considered that the scaling rules must be open to question and a programme of work has been outlined in the U.K. to investigate various aspects of scaling. These are discussed in the following section.
Click to expand...
 
Hawker-Fiat Pact
Fiat is negotiating for a licensed production agreement with Hawker Siddeley Aviation for possible manufacture of the Mach 2.5 P.1154 VTOL strike fighter and will drop its own project in this area, the G.95/6.

In a parallel move, Fiat also is negotiating for license rights to the 32,000lb.-thrust Bristol Siddeley BS.100/9 vectored thrust engine which will power the P.1154.

Move gives impetus to an envisioned multi-nation program for the P.1154 and, for all practical purposes, throws Italian support behind the aircraft in the now-shaky North Atlantic Treaty Organization competition for a V/STOL close support fighter.

In discussing the negotiations. an Italian spokesman pointed out last week that the G.95/6, if continued, would have been in all probability a single-nation program, with Italy absorbing all the costs. With the P.1154, a large share of its development costs have been or will be paid by Great Britain, and other nations may yet participate. Republic Aviation and Fokker also have been discussing possible participation in the P.1154 program with IIawker Siddeley.
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Aviation Week October 15 1962 P31
 
overscan (PaulMM) said:
Hawker-Fiat Pact
Fiat is negotiating for a licensed production agreement with Hawker Siddeley Aviation for possible manufacture of the Mach 2.5 P.1154 VTOL strike fighter and will drop its own project in this area, the G.95/6.

In a parallel move, Fiat also is negotiating for license rights to the 32,000lb.-thrust Bristol Siddeley BS.100/9 vectored thrust engine which will power the P.1154.

Move gives impetus to an envisioned multi-nation program for the P.1154 and, for all practical purposes, throws Italian support behind the aircraft in the now-shaky North Atlantic Treaty Organization competition for a V/STOL close support fighter.

In discussing the negotiations. an Italian spokesman pointed out last week that the G.95/6, if continued, would have been in all probability a single-nation program, with Italy absorbing all the costs. With the P.1154, a large share of its development costs have been or will be paid by Great Britain, and other nations may yet participate. Republic Aviation and Fokker also have been discussing possible participation in the P.1154 program with IIawker Siddeley.
Click to expand...

Aviation Week October 15 1962 P31
Click to expand...

Nice Info my dear PaulMM,

but can you imagine the only reason for cancellation was McDonnell F-4 Phantom-II ?,RAF could
be operating them together,and both had different job !.
 
A Fanfare of Strumpets.

NBMR3 by 10/62 had narrowed to Mirage IIIV vs.P.1154, so jilted losers sought anybed. T.584 rejected, BAC threw themselves at (AMD) Dassault.
D.24 Alliance rejected, Fokker and Republic both prostrated themselves to HSAL., as did SABCA/Belgium, already in bed with AMD. G.95/6 rejected, FIAT clambered onto P.1154, to join Breguet, Focke-Wulf/Avions Fairey and SABCA, who were also on AMD's team. Boeing let it be known they were disposed to AMD, despite already scheming with FRG on (to be) AVS.

As would emerge on nearly all 47 NBMRs...it was all nonsense, because NATO (then) had no procurement budget of its own. The Working Party of Interested Nations declared the winner to be Mirage IIIV...on technical grounds...and P.1154 on Collaboration. So UK 1963 solo-funded P.1154, France, IIIV.

Hesham: F-4 was not the "only" cause for chop, though even UK's Speyed version was dramatically cheaper to buy (and would have been to own, though in 1965 no-one could calculate through-life cost of ownership). When it became clear that those Forces carrying US AW would be unable to disperse from Main Operating Base (because USAF Munitions Teams alone, tied to MOB, could release their sunshine to fly), then VTOL Interested Nations narrowed to US, UK, France, happy to pursue solo schemes. They, in turn, had worked out by the time, 1/68 of AVS' demise, that dispersal was all too hard and that one AW sortie would be possible Long-TOL. So F-111E/F, Mirage 2000N, Tornado and close-up various. (P.1127(RAF) was to have a precise Task on the Hanover autobahn, WE177A to top and tail armour columns, until folk realised how juicy a target that would present to (very) nearby WarPac Special Forces.)

None of the anti-AW Protestors ever rumbled that Long-TOL AW would conflict with public assertions of No NATO First Use.

USSR saw low-payload VTOL as pointless (on land) compared with more Long-TOL platforms for less investment. They had no No First Use confusion.
 
What was the expected empty weight of the 1154 and the 'dry' thrust expected to be on its engine?

I always read about how Plenum Chamber Burning was never going to work, ground/deck erosion and hot gas recirculation, but what I never see asked/answered is why it was necessary in the first place to use PCB for this. Sea Harrier (ultimately carrying 4 AMRAAMs) and others take off and land just fine on water-augmented 'dry' thrust so why was PCB never considered a 'STO and mach 2 facilitator only'?
 
PCB was an NGTE concept meeting the normal Scientific Civil Service mindset, that what can be evolved...should be: by professional
upbringing scientists do not get their hands dirty or bother with mundane grease monkey matters such as maintainability, operability.

The finest example was RAE's post-FIDO infatuation with Blind Landing, down to zero vis. Their Leader Cable concept involved digging long trenches into the threshold. It never crossed their mind that at end of landing roll the a/c could go nowhere, nor could disembarked walking pax then get on a bus.

See also crash survival 9G coffee machines to serve 3G humans.
 
henshao said:
What was the expected empty weight of the 1154 and the 'dry' thrust expected to be on its engine?

I always read about how Plenum Chamber Burning was never going to work, ground/deck erosion and hot gas recirculation, but what I never see asked/answered is why it was necessary in the first place to use PCB for this. Sea Harrier (ultimately carrying 4 AMRAAMs) and others take off and land just fine on water-augmented 'dry' thrust so why was PCB never considered a 'STO and mach 2 facilitator only'?
Click to expand...
P.1154 was still primarily conceived as VTOL.

Harrier STO techniques developed over time after P.1154 cancellation, and the invention of the ski-jump was a key part of making it viable. Sea Harrier deflects the nozzles down at about 40-60 degrees during STO, so there would likely still be potential damage to the decking from PCB.

Harrier development was constantly limited by available power; PCB seems a cheap fix for this. You could takeoff and recover vertically with a full weapons load, or have a payload in STO more comparable to a conventional aircraft.
 
Not really 'proper' info but an anecdote that supports info already posted -

Some years ago, I was looking at a house with a view to buying it. Got talking to the gentleman selling and in the course of the conversation, he mentioned he'd worked on PCB and apparently they all knew it was a 'non-starter' even as they developed it.

Extra info - just to be clear, [and this is based on recollections of a conversation nearly 8 years ago...] the gentleman in question told me it worked alright but just that it wasn't much use ...other than to dig holes.
 
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What would that have done to the usability, range and payload etc?
 
In Mike Pryce's P.1216 book, he covers the PCB problem quite well. The weird aircraft shapes that were designed to get around it are quite interesting (P.1214 & P.1216) He also explains why it would never have gone on an operational Harrier.
 
overscan (PaulMM) said:
PCB worked perfectly from an technical and engine thrust perspective. I think operationally it could be been challenging, but at least a carrier deck could be appropriately designed to cope.
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Same here.
Though I find the whole use of rolling VL for the F-35B ironic. As that was the solution for the P.1154.
 
The RAF 1154 was going to be based at "conventional" airfields in the UK, Germany, the Gulf and Far East.
It would be interesting to know if squadrons intended to deploy away from them as they did with the P1127RAF.
A rolling take off and vertical recovery to damaged airfields seems reasonable.
 
It does come down to the rolling deflected thrust STO technique. If this technique is unknown or not allowed then I agree the problem of PCB affect on the surface seems larger. (Russians simply thermally reinforced the landing area on their ships for the Yak-38 pure turbojet output IIRC) Otherwise, especially with the benefit of hindsight, the jet could be designed to inhibit PCB with the nozzles vectored (and gear down) so the pilot could simply perform the drive-out phase of the takeoff on max output and then vector thrust normally without worry of damage to the deck/surface. After all the engine is working alongside the wing, not doing it alone.

Of course if the jet is designed to hover without PCB the nozzle/engine/CG placement might have to be adjusted for the perceived 'dry' thrust center. One possible benefit though is that, a jet which is neutrally balanced on vectored non-burning nozzles, will have a pitch moment with vectored burning nozzles (because only the forward nozzles burn), and in a potentially favorable way: the classic Vectoring In Forward Flight technique would encourage the nose to rise under burning vectored thrust. That is to say, at minimum this hypothetical 1154 would have a tremendous instantaneous turn rate in that regime particularly at low airspeed.
 
Shed of dread, per your comment in#172, "...in the course of the conversation, he mentioned he'd worked on PCB..."
Was this in Stockport ?? SE of Manchester, UK ??
If so, could just be the guy I knew who scoffed at PCB, but whose team found a 'better' solution, albeit still NDA...
--
Totally un-connected, has any-one seen a twin-Pegasus sorta-Harrier with the engines stacked on centre-line like EE Lightning ??
Probably 'napkinwaffe' but, IIRC, while both engines fed the 'cool' front nozzles, one engine fed the rear nozzles, the other a 'bucket' diverter that, in level flight, fed a genuine after-burner...
 
What was the planned flyoff price for p.1154? Or did they not get to that point.
 
I am wondering whether the RAF planned to use the P1154 in the same way as the later Jaguar rather than the P1127.
The service Harriers especially the later variants rarely operated away from comfortable airbases.
Comparing P1154 with Jaguar seems to me a way of explaining why the P1154 was too complicated for the job and probably too expensive.
The Six Day war in 1967 with Israel smashing Arab aircraft on their airfields led to lots of images of P1127RAF hiding in photos. But noone took these seriously. Switzerland and Sweden stuck to the easier solution of using roads as runways. The UK practised the same with Jaguar though not with Phantoms.
theaviationgeekclub.com

VINTAGE FOOTAGE SHOWS JAGUAR ATTACK AIRCRAFT UNDERTAKING MOTORWAY TRIALS - The Aviation Geek Club

VINTAGE FOOTAGE SHOWS JAGUAR ATTACK AIRCRAFT UNDERTAKING MOTORWAY TRIALS
theaviationgeekclub.com theaviationgeekclub.com
 

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It's a reasonable argument that the Swedes hit the right solution.
As did the French until finances forced them away from the F2 to the cheaper F1.
 
cjc #181: did they not get to that point.
By 2/65 it was not yet possible to guess a Unit Production Price for BS.100, nor the avionics fit. Ministers were uncovering 2 scandals first sniffed when they were in Opposition: pricing at BSEL and at Ferranti. BSEL's scandal was Contract A, Repair of Engines and Contract B, Repair of Spares (intended for those items removed by the User and sent directly to BSEL)....You guessed it: BSEL dismantled complete engines on Contract A and charged parts reclamation to A and to B. Ferranti was Bloodhound eqpt. developed with and priced for valves, then delivered with trannies, no discount offered. A fixed Unit price would not be agreed for Harrier GR.1/Ferranti kit/(ex-BSEL, now RR) Pegasus until 1968.

F-4M (US content) was on offer at fixed Unit Price and that on 10-years' deferred payment. No brainer, after SoS/Def Healey asked one of his simple questions: what sortie required VTO+supersonic dash? None. So he bought enough P.1127(RAF) for the sole V/Really STO sortie: close up near Gutersloh.

uk75 above. Runways. After NBMR3 failed, US+FRG explored their own P.1154 as AVS, intended to replace USAFE F-4C/D and FRG F-104G in the AW role. USAFE could disperse with AW into hides/onto autobahns, but FRG could not, because USAFE Munitions Custodials must Release nukes. By Heidelberg Agreements FRG (et al) Army AW Units had USArmy Custodials deployed, as fighting soldiers, with their SP guns and SSMs: they were under host Command except for Release Authorisation. How do we do that for dispersed aircraft? Should we even try?

WarPac (presumably) had the same issue. So both Pacts chose to assume runway availability - if briefly damaged by HE/dibbers. So AVS was chopped, and 1968 intent that its FRG replacement NKF90/to be Tornado should have shortish TO capability would gently fade.
 
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In previous posts, a link to the P.1154 story in the, now defunct, harrier.org.uk site was shared. That link was based on an article published in the Sprint 2000 issue of the Air Britain journal Aeromilitaria. For those that might be interest, here is the original article:
https://air-britain.com/pdfs/aeromilitaria/Aeromilitaria_2000.pdf

It contains a nice production breakdown of the P.1154 in page 10.
 
There was a long thread about the P1154 and PCB on PPRUNE around ten years ago to which John Farley (the Harrier test pilot) contributed.
To paraphrase what I remember of what he said, he refused to have anything to do with, or fly a PCB Harrier as he believed it was a death sentence for the pilot. He also suggested his views may have been responsible for the P1154 demise.
When asked to explain his rationale was that the aircraft would need to be so heavy that plenum chamber burning would have been essential during takeoff and landing to provide enough vertical thrust. That brought two insoluble problems:
Firstly hot gas ingestion would have stifled the engine, making it flame out.
Secondly the hot blast from the forward PCB nozzles would have destroyed any surface the aircraft was operating from, leading to massive FOD damage to wheels, airframe and engines.
In his view the two together created an insoluble fatal risk.

If you search the old archived section of PPRUNE using John's name you may still be able to find the thread
 
Unfortunately not.
Airfix did make a kit of the prototype P.1127 which has seen reissues every few decades (still pops up on evilbay)
Maintrack Models released vacuform kits of the P.1154 RAF. and RN. versions and Freightdog Resin did make a rather nice 72 scale kit of the P.1154 RAF.
 
randyrippley said:
There was a long thread about the P1154 and PCB on PPRUNE around ten years ago to which John Farley (the Harrier test pilot) contributed.
To paraphrase what I remember of what he said, he refused to have anything to do with, or fly a PCB Harrier as he believed it was a death sentence for the pilot. He also suggested his views may have been responsible for the P1154 demise.
When asked to explain his rationale was that the aircraft would need to be so heavy that plenum chamber burning would have been essential during takeoff and landing to provide enough vertical thrust. That brought two insoluble problems:
Firstly hot gas ingestion would have stifled the engine, making it flame out.
Secondly the hot blast from the forward PCB nozzles would have destroyed any surface the aircraft was operating from, leading to massive FOD damage to wheels, airframe and engines.
In his view the two together created an insoluble fatal risk.

If you search the old archived section of PPRUNE using John's name you may still be able to find the thread
Click to expand...

Found it (me thinks) https://www.pprune.org/military-aviation/478767-no-cats-flaps-back-f35b-26.html
John Farley posts are well worth a read.
https://www.pprune.org/7144279-post514.html
https://www.pprune.org/7144498-post517.html
 
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overscan (PaulMM) said:
PCB worked perfectly from an technical and engine thrust perspective. I think operationally it could be been challenging, but at least a carrier deck could be appropriately designed to cope.
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Probably need to wet down the carrier deck to prevent it from catching fire.
Hah!
Hah!
 
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