Bae P.112

[dy031101]

I recently bought "British Secret Projects: Jet Fighters Since 1950", and it mentions a BAe P.112, saying that it "utilised a promising new advanced engine configuration called RALS (remote augmented lift system) which, besides the main rear nozzle, had a pair of remote nozzles at the front taking bleed air from the main jet."

Three questions I'd very much appreciate if experts can elaborate:

1. what does bleed air mean? (I wanna make sure.)

2. what are the exact locations of the remote nozzles?  Just in front of the main engine, or somewhere around the forward fuselage?

3. it came from ASTOVL studies, but can it indeed land vertically?

Thanks very much in advance.






Hum...... it's hard not to think of it as related to BAe P.106, experience on which was used for development of JAS-39 as well...... you know...... if RALS allows for vertical landing and Gripen can use RALS......

[elmayerle]

In answer to your questions:

1.  It's air taken from (bled off) the engine compressor after a few stages.

2.  From what I've seen in papers and such, the RALS nozzles are generally at the front of the aircraft.

3.  From all descriptions, it was intended primarily for vertical ops.

From what I've read, it also sounds like something of a fuel guzzling approach, which may be one reason it never made flying hardware.

[dy031101]

From what I've read, it also sounds like something of a fuel guzzling approach, which may be one reason it never made flying hardware.

Hum...... even in short takeoff mode?

(Vertical takeoff and vertical landing are expected to be fuel guzzling, aren't they?)

[elmayerle]

Yes, even in stol operations.  The idea is to take high-pressure bleed air, duct it to where you want the nozzle, mix in fuel, and ignite it like an afterburner to provide a secondary lift jet.  By its nature, this is going to guzzle fuel as without the burning, you're looking at no more than the attitude control jets as used by the Harrier or, in a more limited manner, for roll control on the F-35B.

[Zen]

RALS, remote augmented lift System.

In diagrams I've seen it shows a pegasus like engine, but the bypass (fan) air is ducted via pipework to a nozzle near the front of the aircraft, that nozzle is a variant of the PCB type (plenum chamber burning - a type of very short reheat).

When not in VL mode the air is then ducted via pipework to a seperate rear nozzle where a conventional afterburner is located.

The rest of the engines flow is seperate as is its afterburner and vectoring nozzle.

P112 seems to utilise two RALS, but their drawn from one engine, likely a direct Pegasus variant, so as they can use its existing twin ducting for the forward nozzles.

[Thorvic]

P116 Model from Warton

[Thorvic]

And another view

[Thorvic]

Ditto

[Thorvic]

Undersides

(I got these photos when the guy was selling them on ebay after the projects division closed down at Warton - I never saw them i just asked for additiona shots and got these.  I think he made in the region of about 2-3 grand off the sales !!!)

[dy031101]

P116 Model from Warton

Thanks a lot!

I was engaged in a brain-storming exercise on a what-if scenario continuing from the Mirage IIIV discussion (for its replacement in this case, at least as sophisticated as Gripen and excluding F-35B)......

[Archibald]

P116 Model from Warton

Thanks a lot!

I was engaged in a brain-storming exercise on a what-if scenario continuing from the Mirage IIIV discussion (for its replacement in this case, at least as sophisticated as Gripen and excluding F-35B)......

Yeah a flyoff between P.112 and General Dynamics type 200!    

[dy031101]

Yeah a flyoff between P.112 and General Dynamics type 200!

That's Pegasus development with afterburning twin ducting VS some thrust-vectoring turbofan with two liftjets...... which one, in people's estimation, would be more efficient (i.e. would the afterburning ductings burn more fuel and weigh more than two liftjet engines)?

What about the weapons fit of BAe P.112?  If the P.106 before was any indication, wouldn't it probably have two wingtip Sidewinder rails and at least six underwing hardpoints to play with?

How could GD Model 200 have evolved by the time BAe P.112 was cooked up?

[Archibald]

IHMO the Pegasus reached its limits quickly. Fan diameter is rather big, so building a supersonic aircraft around a Pegasus is rather difficult (albeit certainly not impossible).

The Type 200 looks much better than this fat P.112    

[dy031101]

Here's another P.112 artist impression that I found.

Six hardpoints for AAMs and two wingtip pods (probably as part of EW suite).

[elmayerle]

I'd say the engine is more likely a derivative of the late-model Pegasus, but with a lower bypass ratio fan; alternatively, it's a new twin-spool design to much the same ratings and requirements.  In either case, I'd love to see test-rig data for the RALS system as I truly wonder about duct flow loses causing performance problems.  IMHO, for the simplest vstol engine installation, a "three-poster" with PCB appears the simplest, likely followed by - if you could get very reliable mechanicals - the tandem fan concept.  The way taken with the X-35B/F-35B is simpler than additional lift jets, but it has its own peculiar problematic aspects.