Another interesting Martin-Baker bird the MB.4

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Bill-Higdon

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Found this one today
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The second of the three MB.3 prototypes ordered by MAP, R2496, was intended to be Griffon-powered, and was referred to as the MB.4. At the time of R2492's crash, the necessary drawing amendments for the MB.4 were complete and manufacture had started.
It was intended to enter the competition against Specification F6/42 but the attempt was unsuccessful. However, Martin felt that he could improve on the MB.3/MB.4 concepts. R2496 was left uncompleted and work on the third intended aircraft, R2500, was not begun. Early in 1943, the difficult decision was taken to start afresh, tempered by the knowledge that the firm had received verbal assurances from MAP that if a new fighter design were produced, a contract for one prototype would be awarded, again to Specification F5/39.
With the then hand-built nature of a prototype, in an experimental shop, with design adjustments made on the spot, and drawings brought into line afterwards, made resources available out of all proportion to the effort. By 1943, when work on the MB.5 had begun.
 

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Vigilant1

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They are good looking planes. I wonder why the fuselage was kept relatively deep all the way back to the tail. Maybe it was simpler to build, maybe the depth allowed adequate strength with reduced number/thickness of longerons in the rear, etc. It should have allowed a slightly smaller fin, anyway.
 
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cluttonfred

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They are good looking planes. I wonder why fuselage was kept relatively deep all the way back to the tail. Maybe it was simpler to build, maybe the depth allowed adequate strength with reduced number/thickness of longerons in the rear, etc. It should have allowed a slightly smaller fin, anyway.

I suspect you’re right on both the structural and aerodynamic intended benefits. The original drawings for the MB2 had no fin at all, just a rudder on the fuselage, though I don’t know if it flew that way. It soon grew a small fin and finally a conventional fin and rudder.

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Riggerrob

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I suspect you’re right on both the structural and aerodynamic intended benefits. The original drawings for the MB2 had no fin at all, just a rudder on the fuselage, though I don’t know if it flew that way. It soon grew a small fin and finally a conventional fin and rudder.

View attachment 129633
Either built it with a deep fuselage - with square corners - or add on a dizzying array of dorsal fins, ventral fins, strakes, etc. to tame spin characteristics. See the modern turbo-prop trainers: Diamond, Epsilon, Grob, Harvard II, Pilatus PC-?, Texan II, Tucano, etc.
 

Vigilant1

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The "generous" gear spats/fairings on early fixed gear versions added quite a bit of side area (slightly) forward of the CG, so I can understand needing to have quite a bit aft as well to get the CP correct for positive yaw stability. But, you can get away with a smaller amount of area (and less skin friction drag) if it is further aft.

Battle damage tolerance is also a consideration, and that thick rear fuselage would have survived a lot of holes and remained structurally okay.
 

flitzerpilot

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It was a shame that the MB-3 was destroyed before the test programme was completed. The aircraft as built had a more conventional upper rear fuselage without the all-round vision hood, although later drawings and 'doctored' photographs of the first prototype showed the later hood, as illustrated in the side view of the MB-4.

The later MB-5 on test proved to be an outstanding fighter on many levels and would have been one of the fastest single-engined fighters of the war. It had beautiful handling and the aerobatic displays performed by test pilots were remarked on as exceptional, demonstrating
superb manoeuvrability. The access to systems and to gun bays were described as excellent and would have facilitated rapid servicing and re-arming.

The replica, using some Mustang components, was merely a lookalike, but nonetheless was a genuine attempt by enthusiasts to re-create something of the original and much credit must be given them for that endeavour.
 

cluttonfred

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A simplified, scaled-down MB2 would make a great starting point for an original design in the spirit of a 1930s racer. An upright Suzuki conversion from Aeromomentum or Air Trikes would suit it well with cowling taller than it is wide and the spinner centered vertically on the cowling like the MB2. You might even be able to work a pair of racing motorcycle radiators into the two spats instead of the MB2’s single oil cooler. 7/8 scale gives a 29’ 9” span, 30’ 5” length, and 162 sq ft of wing area so not at all small, in fact, it would make a nice two-seater. 3/4 scale gives 25’ 6” span, 26’ 1” length, and 119 sq ft of wing area so still a generous size for a big and tall pilot, fuel for good range, and baggage.

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cluttonfred

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What is the cooling system architecture? That little scoop on the lower cowl in the OP can't possibly support coolant, oil, and intercooler.

Napier Dagger was an air-cooled 24-cylinder H-type engine, basically two vertically-opposed flat-12 engines side-by-side on a common block. The top air intake cooled the two rows of six upright cylinders on top and the botTom intake did the same for corresponding inverted cylinders on the bottom. The oil cooler was in the left landing gear fairing.

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Riggerrob

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A simplified, scaled-down MB2 would make a great starting point for an original design in the spirit of a 1930s racer. An upright Suzuki conversion from Aeromomentum or Air Trikes would suit it well with cowling taller than it is wide and the spinner centered vertically on the cowling like the MB2. You might even be able to work a pair of racing motorcycle radiators into the two spats instead of the MB2’s single oil cooler. 7/8 scale gives a 29’ 9” span, 30’ 5” length, and 162 sq ft of wing area so not at all small, in fact, it would make a nice two-seater. 3/4 scale gives 25’ 6” span, 26’ 1” length, and 119 sq ft of wing area so still a generous size for a big and tall pilot, fuel for good range, and baggage.

View attachment 129672
Amusing how most of the airframe is simple, straight lines or simple single curves, but the horizontal tail is elliptical.

Did they hire an outside engineer (Supermarine or Heinkel) to design the tail? We all know how well outside engineers contributed to the wing design of the Messerschmitt 210. Hah! Hah!

Seriously, an elliptical tail makes sense if you are bending and laminating tip-bows with multiple layers of wood.
 

Tiger Tim

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Napier Dagger was an air-cooled 24-cylinder H-type engine, basically two vertically-opposed flat-12 engines side-by-side on a common block. The top air intake cooled the two rows of six upright cylinders on top and the botTom intake did the same for corresponding inverted cylinders on the bottom. The oil cooler was in the left landing gear fairing.

View attachment 129674
What a monster that is! Imagine living a life where you rely on all the parts of that thing cooperating.

For your scale replica I’m now wondering if two Rangers could be Frankensteined together into some sort of vertically opposed twelve cylinder…
 
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