thinking time Vought f7u Cutlass (Gutless)

[lenny100]

The Vought F7U Cutlass was a the time a highly unusual, semi-tailless design, allegedly based on aerodynamic data and plans captured from the Germans.

Regarded as a radical departure from traditional aircraft design, the Cutlass suffered from numerous technical and handling problems throughout its short service career. The type was responsible for the deaths of four test pilots and 21 other U.S. Navy pilots. Over one quarter of all Cutlasses built were destroyed in accidents.
The poor safety record was largely the result of the advanced design built to apply new aerodynamic theories and insufficiently powerful, unreliable engines.
So the royal navy sees potential as a night fighter to replace the Sea hawk on the smaller carriers were the larger sea vixen could not operate. now the wanted a UK engine to replace the Westinghouse J46-WE-8B turbojets s details below.

General characteristics

   Type: Afterburning Turbojet
   Length: 198 in (5.0 m)
   Diameter: 34 in (0.86 m)
   Dry weight: 2100 lb (952.5 kg)

Components

   Compressor: Single-Spool, 11-stage Axial
   Combustors: Annular
   Turbine: 2-stage turbine

Performance

   Maximum thrust: 4800 lbf (21.4 kN) dry, 6,000 lbf (26.7 kN) afterburning
   Overall pressure ratio: 6:1
   Air mass flow: 70 lb/sec
   Thrust-to-weight ratio: 2.3:1 dry, 2.9:1 afterburning

now i have had several thoughts

1  2X Bristol Siddeley Orpheus as used in the "gnat". its slightly smaller in size and has a simler dry thrust, and is reliable, but i can't find if they ever thought about fitting a afterburner!

2  2xRolls-Royce Avon RA.7R although i can't fined the size of this early engine only the later big boys!

Am i thinking along the right lines?

[The Rat]

Sounds good so far. The Cutlass is one of those aircraft that absolutely demands to be whiffed, and a new engine is the first thing that has to be done. Another mod I've had running around in my brain is an extended forward fuselage with canards.

[Dizzyfugu]

A Cutlass derivate that I'll tackle some time is a (real!) twin-turboprop version! It had slender engine nacelles in front of the fins, and a more slender fuselage, even with a tail barbette, IIRC. THAT should look cool... 

Anyway, a RN/FAA Cutlass should look nice - there were already several Panthers/Cougars, and different guises from the well-known dark blue overall suit these aircraft well. 

[JayBee]

1  2X Bristol Siddeley Orpheus as used in the "gnat". its slightly smaller in size and has a simler dry thrust, and is reliable, but i can't find if they ever thought about fitting a afterburner!

The proposed supersonic Gnat Mk5 was to have two RB 153R engines, alternatively two Viper 20s. I have no idea about the output of these engines.

How about the RR Avon RA14R as proposed for the P1083 thin wing Hunter.

Jim

[Old Wombat]

Well, with the later RA.24 series being approx 127" long & 42" diameter with afterburner, the RA.7 or RA.14 should both fit nicely (although, like the CAC Sabres, the Cutlass' will need fatter engine housings.

The (UK) National Archives have the following publications;
- Established Performance Data and Installation Notes: Avon Mark 1 Engine  PA1716/5/12/29  1950s
- Estimated Performance Data and Installation Notes: Avon R.A. 50 Rating Engine  PA1716/5/12/22  1950s
- Provisional Performance Data and Installation Notes: Avon R.A. Rating Engine  PA1716/5/12/21  November 1952
- Aero Engine School Course Notes: Avon 100 Series  PA1716/5/12/4  1955
- Provisional Performance Data and Installation Notes: Avon R.A.24 Rating Engine  PA1716/5/12/23  October 1955
- Estimated Performance Data and Installation Notes: Avon R.A.29 Rating Engine  PA1716/5/12/27  December 1955
- Provisional Performance Data and Installation Notes: Avon Mk. 522, 524 and 525 Engines  PA1716/5/12/3  1957
- Estimated Performance Data and Installation Notes: Avon Engine R.A. 29 Stage 3  PA1716/5/12/24  March 1957
- Estimated Performance Data and Installation Notes: Avon Engine R.A.29 Stage 4 Performance Rating  PA1716/5/12/28  March 1957
- Established Performance Data and Installation Notes: Avon Mk.202 Engine  PA1716/5/12/5  June 1958

Interestingly they also have this;
- Provisional Performance Data and Installation Notes: Avon R.A. 28 Rating Engine  PA1716/5/12/9  November 1953

Which indicates that the RA.28 series engines were available in 1953/54.

Unfortunately, I have no idea how to access the information in these, except by visiting the (UK) National Archives in person.

However, given that F7U Cutlass' were in service from 1954 to 1959 the Avon RA.24R Mk.200R engines from the Lightning F.1/F.1A, in service from 1959, may be suitable.

These are listed as having the following attributes/dimensions;

Dry Thrust:  11,250 lbf
Wet Thrust: 14,370 lbf
Length:       126.9"
Diameter:    42.0"

Or the closer period engine, the Armstrong Siddeley Sapphire ASSa.6 Mk.101 used in the Hunter F.2/F.5, Hunter prototype, Javelin F(AW).1/F(AW).2/T.3/F(AW).4/F(AW).5/F(AW).6 with a dry thrust of 8,300 lbf (no wet...ish figures until the ASSa.7);

Specifications (ASSa.7 / 7LR) (from Wikipedia: http://en.wikipedia.org/wiki/Armstrong_Siddeley_Sapphire)

General characteristics
   Type: ASSa.7 Turbojet, ASSa.7LR Augmented turbojet
   Length: ASSa.7 125.2 in (3,180 mm), ASSa.7LR 293 in (7,442 mm)
   Diameter: 37.55 in (954 mm)
   Dry weight: ASSa.7 3,050 lb (1,383 kg), ASSa.7LR 3,180 lb (1,442 kg)

Components
   Compressor: 13 stage axial flow
   Combustors: Annular with 24 hockey-stick vaporisers
   Turbine: Two stage
   Fuel type: Aviation kerosene to DERD 2482 or DERD 2486
   Oil system: Flood feed, minimum oil pressure 12 psi (83 kPa), tank capacity 18 imp pt (10 l), oil grade to DERD 2487.

Performance
   Maximum thrust: ASSa.7 11,000 lbf (49 kN) at sea level at 8,000 rpm, ASSa.7LR 12,390 lbf (55 kN) above 20,000 ft (6,096 m).
   Specific fuel consumption: 0.885 lb/hr/lb (90.214 kg/kN/hr) at Take-off rating
   Thrust-to-weight ratio: 3.607 lbf/lb (0.035 kN/kg)

Probably no help... but I tried!