What if? Grumman Sabrecat Mk. II; aircraft "C-3M/JZ931 of 800 NAS, Fleet Air Arm; 1945

[dizzyfugu]

Ich poste das Ding mal, weil es einen 2014 "Whiffie" (auf whatifmodelers.com) gewonnen hat - und ich muss etwas ausholen. Eigentlich ging alles mit dieser naiven Skizze los, die ein Jung-Modellbauer auf Anregung eines anderen Bastlers gepostet hatte:



Das wiederum hat gleich zwei Leute (mich inklusive) angeregt, diese ummotorisierte Grumman Bearcat, nun aufgrund des Motors in "Sabrecat" umgetauft, als Modell(e) zu bauen.

Und dies ist bei mir dann daraus geworden:

Some background:
The so-called 'Sabrecat' was a special high performance derivate of Grumman's F8F Bearcat for the British Navy's Fleet Air Arm, tailored to the needs in the Pacific WWII theatre.

The original Bearcat concept began during a meeting between Battle of Midway veteran F4F Wildcat pilots and Grumman Vice President Jake Swirbul at Pearl Harbor on 23 June 1942. Lieutenant Commander Jimmie Thach emphasized one of his most important factors in fighters to Mr. Swirbul, "climb rate", which connoted "power." After intensively analyzing carrier warfare in the Pacific Theater of Operations for a year and a half, Grumman commenced designing the G-58 Bearcat.

, on Flickr

on Flickr

Work on the Bearcat began in 1943 with the specifications calling for an aircraft able to operate from the smallest carrier, primarily in the interceptor role. The F6F's Pratt & Whitney R-2800 engine was retained, but compared to the Hellcat, the Bearcat was 20% lighter, had a 30% better rate of climb and was 50 mph (80 km/h) faster - it was, effectively, the smallest possible airframe mated with a strong and proven engine. Compared to the larger F6F, range was necessarily sacrificed, but rate of climb and agility were superior.

The FAA had immediate interest in the type for its carriers in the Pacific, too, since such a fast and agile type was missing in the British arsenal. But the FAA demanded that the type would be adapted to British standards, and also carry a domestic engine - the powerful Napier Sabre had already been chosen. The Sabre was a very different engine, though: a H-24-cylinder, liquid cooled, sleeve valve, piston aero engine, designed by Major Frank Halford. It was a promising engine: in its early stages in 1938 it had been developing 2,200 hp (1,640 kW), and this should reach up to 3,500 hp (2,600 kW) in late-model prototypes.

, on Flickr

, on Flickr


The Sabre engine necessitated a redesign of the complete Bearcat forward fuselage, though, including a large, chin-mounted radiator for the water-cooled engine. The oil coolers in the wing roots were retained. For the Sabrecat, a modified version of the Sabre III (intended for the stillborn Blackburn Firebrand naval fighter), the Sabre IIIA, was chosen. This engine was based on the Sabre IIA, but featured a revised ignition system with a maximum boost of  9 lbs and a Hobson fuel injection system. On the original Sabrecat, the Sabre IIIA drove a large, four-bladed Rotol propeller with a spinner. The Sabrecat's performance (considering rate of climb and top speed) was slightly better than the original F8F-1's, even though its range fell shorter.

From the start, many equipment pieces were replaced by equivalents of British origin, including the armament. This comprised four 20mm Hispano cannons and various external stores unter the wings, inclusing drop tanks, bombs of up to 1.000 lb calibre or six unguided air-to-ground rockets. Other differences to the Bearcat were not so obvious, e. g. the lack of the F8F's unique detachable wingtip system (if the "g"-force exceeded 7.5 "g", then the tips would snap off, leaving a perfectly flyable aircraft still capable of carrier landing).

, on Flickr

, on Flickr


The first F8F prototype for the US Navy flew on 31 August 1944, and the first Sabrecat only three months later, on 1 December 1944. Development was rather quick, since many improvements of the F8F were immediately integrated into the Sabrecat's design.

The first production aircraft for both USN and FAA were delivered in February 1945, and the Sabrecats were immediately thrown into service - now designated Sabrecat Mk. I and initially based on the carrier HMS Indomitable, serving alongside FAA F6F and F4U fighters.

One specific flaw of early Sabrecats turned out to be its poor directional stability, caused by the draggy chin radiator. An enlarged/higher tail fin solved the problem (this fin was later incorporated into the USN's improved F8F-2) at high speeds, and this detail was changed after only 20 aircraft had been built. Nevertheless, the large propeller of the Mk. I Sabrecats caused considerably handling trouble at low speeds and made starting and landing on carrier decks more than hazardous.

Since the already nose-heavy and short aircraft precluded the use of a contra-rotating propeller, trials with a 5-bladed propeller of smaller diameter were hastily undertaken, and this eventually lead to, after only 35 produced Mk. I Sabrecats, the modified Mk. II, which served in parallel.
At this time, the WWII hostilities were already coming to an end. Only 16 Mk. II Sabrecats were eventually built and delivered to the FAA until May 1945, and these were only used for about seven weeks - mostly from land bases, and as fighter bombers against ships and ground targets.

, on Flickr

, on Flickr


After the hostilities ceased, all Sabrecats were quickly withdrawn from service, since other types offered more versatility and even better performance.


General characteristics
Crew: 1 pilot
Length: 30 ft 4.5 in (9.28 m)
Wingspan: 35 ft 10 in (10.92 m)
Height: 13 ft 9 in (4.21 m)
Wing area: 244 ft²[42] (22.67 m²)
Empty weight: 7,070 lb (3,207 kg)
Loaded weight: 9,600 lb (4,354 kg)
Max. takeoff weight: 12,947 lb (5,873 kg)

Powerplant
1× Napier Sabre IIIA 24 cylinder H-engine, 2.300 hp (1.691 kW)

Performance
Maximum speed: 447 mph (720 km/h) at 18,000 ft (5,500 m)
Range: 700 mi (1.127 km) with internal fuel; 1.040 mi (1.675 km) with two 90 gal drop tanks
Service ceiling: 36,500 ft (11,125 m)
Rate of climb:  4,700 ft/min (23.9 m/s)
Wing loading: 66.7 lb/ft² (192.1 kg/m²)
Power/mass: 0.22 hp/lb (360 W/kg)

Armament
4× 20 mm Hispano Mk II cannon
6× 3 in (76.2 mm) RP-3 unguided air-to-ground rockets; alternatively, 6× 250 lb (113.5 kg), 2× 500 lb (227 kg) or 2× 1,000 lb (454 kg) bombs could be carried, or 2× 45 gal (205 l) or 90 gal (409 l) drop tanks.


, on Flickr

, on Flickr


Das Basismodell ist die sehr gute, rel. neue Mixed-Media-Bearcat von ART Model aus Osteuropa, der Napier Sabre stammt von der Matchbox Hawker Tempest, die den kompletten Bug als Optionsteil enthält. Ansonsten ist der Propeller neu (von Pavla, für eine Griffon-Spitfire) und die britischen Flugkörper anstelle der amerikanischen HVARs.
Bemalung und Markierungen orientieren sich an einer Grumman Hellcat der FAA aus 1945 - wie üblich alles mit Emaille-Farben und Pinsel gemacht.