View Full Version : Whirly€¦ Update

12-14-2005, 09:28 AM











To be continued...

12-14-2005, 09:49 AM
I waaaaant a Whirlwind!

12-14-2005, 09:53 AM

12-14-2005, 11:19 AM

12-15-2005, 05:35 AM
Good read. Thanks, old boy.

12-15-2005, 06:00 AM
Good read thanks.

Whirlwind rocks, has always looked better than that Mozzie...

12-15-2005, 12:25 PM
She certainly is a beauty!


12-15-2005, 12:34 PM
She certainly is.



12-15-2005, 01:34 PM
Extremely Good article... Thank's for Posting.

12-16-2005, 01:46 PM
Just in case there is anyone out there who doesn't know about Peregrines ands Whirlies, I've had the following away from Wikipedia:-


The Peregrine was a 885hp liquid-cooled V-12 aircraft engine designed by Rolls Royce in the early 1930s. It was essentially a "rationalized" version of their Rolls-Royce Kestrel, which had seen widespread use. The introduction of a "ground level" supercharger and several design changes improved the power-to-weight ratio considerably, and it was generally felt that the new Peregrine would be the "standard" fighter engine for the upcoming war. Two Peregrines bolted together on a common crankshaft would produce the Rolls-Royce Vulture, a 1,700 hp X-24 which would be used for bombers.

As it turned out, aircraft designs rapidly increased in size and power requirements to the point where the Peregrine was simply too small to be interesting. Rolls' internal project to "fill in the gap" between the Peregrine and Vulture resulted in the Rolls-Royce Merlin, which as a more attractive competitor annihilated any demand for the smaller, less powerful Peregrine.

In the end only two aircraft used the Peregrine, the Westland Whirlwind and the Gloster F9/37, both twin-engine designs. The F9/37 was never developed beyond prototype stage, and the Whirlwind, despite having excellent low-altitude performance, proved uneconomical compared with single-engined fighters, and also suffered from reliability problems. Only small numbers of Whirlwinds - and therefore of Peregrines - were built.

While reliability problems were not uncommon for Rolls-Royce's new engine designs of the era, the company's testing department was told to spend all of their time on developing the more powerful Merlin to maturity. As a result of the Merlin's priority, the unreliable Peregrine was abandoned, its production ending in 1940.

Configuration: V-12, liquid cooled, supercharged
Bore and Stroke:
Displacement: 2,223 cu. in.
Performance: 885 hp

The Whirlwind was a small twin-engine heavy fighter from the Westland Aircraft company. It was one of the fastest aircraft in the air when it flew in the late 1930s, and much more heavily armed than anything flying. Protracted development problems with the Rolls-Royce Peregrine engines it relied on delayed the entire project, and only a relatively small number were built.

A serious problem for air planners of the 1930s was that one could build a nimble plane only if it was small. Such a plane had the problem of not having enough range to fight in anything other than defensive operations, and could not take the fight to the enemy. The only way that a plane could lift enough fuel to do so would be to mount two engines, but it seemed that any plane large enough would be too unwieldy to fight its single engine counterparts.

The Germans and US pressed ahead with such programs anyway, resulting in the Messerschmitt Bf 110 and the Lockheed P-38. Soon the Luftwaffe was boasting that the 110 could beat any single engine fighter, and do so while operating at long ranges escorting their bombers. This piqued the interest of the Air Ministry who finally decided to try their hand at such a plane, and sent out a contract for designs. Gloster, Hawker and Westland all responded, with the Gloster F.9/37 and Westland F.37/35 designs given the go-ahead (Hawker was busy with the Hurricane).

Westland's design team, under the new leadership of Teddy Petter (who later designed the English Electric Canberra and Lightning), returned a plane that employed state-of-the-art technology. The fuselage was a small tube with a T-tail at the end, built completely of stressed-skin monocoque duraluminum. The pilot sat high under one of the world's first full bubble canopies, and the low and forward location of the wing made for superb visibility (except directly over the nose). In the nose were four 20 mm cannons, making it the most heavily armed plane of its era, and their clustering meant there were no aiming problems as there are with wing-mounted guns.

The plane was quite small, only slightly larger than the Hurricane in overall size, but smaller in terms of frontal area. All of the wheels fully retracted and the entire plane was very 'clean' with few openings or bumps. Careful attention to streamlining and two 885 hp Peregrine engines drove it to over 360 mph, the same speed as the latest single-engine fighters mounting much larger engines. The speed quickly garnered it the nick-name Crikey, meaning "my god!" or more accurately "Christ's keys".

The prototype flew on October 11 1938 and production started early the next year. It had excellent handling and it was considered to be very easy to fly at all speeds. The only exception was landing, which was all too fast. Fowler flaps were added to correct for this problem, which also required the horizontal stabilizer to be moved up, out of the way of the disturbed air flow when the flaps were down. Hopes were so high for the design that it remained 'top secret' for much of its life, although it had already been mentioned in the French press.

But there were problems as well. The plane actually had quite short range, under 300 miles combat radius, which made it less than useful as an escort. More troublesome was the continued failure of the Peregrine engines. Originally intended to be one of Rolls' main designs, the Merlin had since become much more important to the war effort and the Peregrine was ignored. Soon the engine was cancelled outright, and since much of the performance of the plane depended on the careful streamlining around that specific engine, there was little choice but to cancel the plane as well.

Westland argued for the creation of the Mk. II model using two Merlin engines, but by this time the role was becoming less important. As Bomber Command turned to night bomber missions the need for an escort fighter became less important. Meanwhile by this time the Supermarine Spitfire was mounting 20 mm cannons, so the 'cannon armed' specification was also being met. The main qualities the RAF were looking for in a twin was range and ordnance load (to allow for the carriage of radar), which the Bristol Beaufighter could do just as well as the Whirlwind.

In the end only 116 Whirlwinds were produced in total, arming two squadrons (No. 263 Squadron RAF in July 1940 and No. 137 Squadron RAF in November 1941). Due to their good low-altitudes performance, they were used primarily as strike fighters and referred to as Whirlybombers. However even this role was soon marginalized with the introduction of the Hawker Typhoon, and the Whirlwind was removed from service in late 1943. Today none exist.

In 1941 the Luftwaffe started a number of extremely high-altitude bombing missions using specially modified Junkers Ju 86 bombers and Messerschmitt Bf 109 fighters carrying bombs. These were met by modified Spitfires, but the pilots were extremely exhausted as a result of the forced-air breathing system. The Air Ministry then ordered a new purpose-built high-altitude fighter with a pressurized cockpit, and Westland responded with a modified Whirlwind known as the Welkin However the Germans called off the attacks, unaware of the British problems, and the Welkin was produced in an even more limited number, only 77.

Specifications (Whirlwind)

General Characteristics
Crew: one pilot
Length: 32 ft 3 in (9.83 m)
Wingspan: 45 ft 0 in (13.72 m)
Height: 11 ft 7 in (3.53 m)
Wing area: 250 ft² (23 m²)
Empty: 8,310 lb (3,768 kg)
Loaded: 10,356 lb (4,697 kg)
Maximum takeoff: 11,410 lb (5,175 kg)
Powerplant: 2 x Rolls-Royce Peregrine I, 885 hp (660 kW) each

Maximum speed: 360 mph (560 km/h)
Range: 808 miles (1,300 km)
Service ceiling: 30,315 ft (9,240 m)
Rate of climb: ft/min ( m/min)
Wing loading: 41 lb/ft² (204 kg/m²)
Power/Weight: 0.17 hp/lb (0.28 kW/kg)

4x Hispano 20 mm cannon in nose
2x 250 lb (115 kg) or 500 lb (230 kg) bombs

The Welkin was a twin-engine heavy fighter from the Westland Aircraft company, designed to fight at extremely high altitudes in the stratosphere. It was created in response to the arrival of modified Junkers Ju 86 bombers flying reconnaissance missions which suggested the Luftwaffe might attempt to re-open bombing of England at high altitudes. In the end this threat never materialized, and the Welkin was produced only in small numbers.

The Welkin was essentially an evolution of the Whirlwind, fitted with a much larger wing, new engines in the form of Rolls Royce Merlin 76/77's, and a pressurized cockpit. The last item required the majority of the effort in designing the Welkin. After extensive development a new cockpit was developed that was built out of heavy-gauge duraluminum bolted directly to the front of the main spar. The cockpit hood used an internal layer of thick perspex to hold the pressure, and an outer thin layer to form a smooth line. Heated air was blown between the two to keep the canopy clear of frost.

The pressurization system was driven by a Rotol supercharger attached to the left-hand engine, providing a constant pressure of 3.5 lb/in² (24 kPa) over the exterior pressure. This resulted in an apparent altitude of 24,000 ft (7,300 m) when the plane was operating at its design altitude of 45,000 ft (13,700 m). This apparent altitude is still too high for normal breathing, so the pilot still had to wear an oxygen mask during flight. A rubber gasket filled with the pressurized air sealed the canopy when the system was turned on, and a valve ensured the pressure was controlled automatically.

Other than that, changes were minor. The wings were so large that the Fowler flaps used on the Whirlwind weren't needed, and were replaced by a simple split-flap. The extra wing area also required more stability, so the tail was lengthened to provide a longer moment arm.

By the time the plane was complete and rolling off the line, it was apparent that the Germans had lost interest in the high-altitude mission, due largely to successful interceptions by specially modified Supermarine Spitfires. In the end only 75 Welkins were produced. A two seat version known as the Welkin Mk. II was produced in only two examples.

The Welkin was seriously handicapped by compressibility problems exacerbated by its long but thick wings, causing the flyable speed range between high-incidence stall and shock-stall to become very small at high altitudes - any decrease in airspeed causing a 'normal' stall, any increase causing a shock-stall due to the aircraft's limiting critical Mach number. This reduction of the speed envelope is a problem common to all subsonic, high-altitude designs and also occurred with the later Lockheed U-2. When W. E. W. Petter came to design his next aircraft, the English Electric Canberra, it was distinguished by noticeably short wings.

Specifications (Welkin)

General Characteristics
Crew: one pilot
Length: 41 ft 6 in (12.67 m)
Wingspan: 70 ft 0 in (21.30 m)
Height: 15 ft 9 in (4.80 m)
Wing area: 250 ft² (23 m²)
Empty: 8,310 lb (3,768 kg)
Loaded: 10,356 lb (4,697 kg)
Maximum takeoff: 11,410 lb (5,175 kg)
Powerplant: 2x Rolls-Royce Merlin 76, hp ( kW) each

Maximum speed: 385 mph (625 km/h)
Service ceiling: 30,300 ft (9,237 m)
Rate of climb: ft/min ( m/min)
Wing loading: 41 lb/ft² (204 kg/m²)
Power/Mass: hp/lb ( kW/kg)

4x 20 mm Hispano cannon in nose

12-16-2005, 02:51 PM
Low_Flyer_MkII... Excellent article.


<span class="ev_code_YELLOW">Welkin Fighter</span>


12-16-2005, 04:12 PM
I copied every word http://forums.ubi.com/images/smilies/10.gif


12-16-2005, 04:49 PM
http://forums.ubi.com/images/smilies/16x16_smiley-surprised.gif http://forums.ubi.com/images/smilies/16x16_smiley-very-happy.gif


12-16-2005, 05:10 PM
Based on those pages, sounds like the thing was a hazard to fly, and had a low dive speed. Wouldn't fair too well against the 109s in the dive based on those figures, I'd say.

12-16-2005, 05:19 PM
Low_Flyer_MkII... So what is Your Wife going to say about that New Aircraft Kit... has she cooled down from the Last Purchase??? http://forums.ubi.com/groupee_common/emoticons/icon_biggrin.gif

12-16-2005, 06:19 PM
Goddammit..that Pidgeon is overmodelled,... http://forums.ubi.com/images/smilies/blink.gif

12-17-2005, 05:50 AM










12-17-2005, 08:22 AM
May I have some more, please, Sir?

12-17-2005, 10:46 AM
Great reading, always loved the sleek look of the whirlwind!...

Regards... Dave S.

12-17-2005, 10:49 AM
Excellent armament for the time!

Imagine those guns for bringing down Heinkels in the BOB!

I think it would have been there in 1940 wouldnt it? Had they done a full production run?

12-17-2005, 11:43 AM
Whilst it was indeed operating with a fighter squadron in July 1940, numbers were somewhat low. The Whirly had to wait until February 1941 for it's first kill - an Arado floatplane.

12-17-2005, 11:53 AM
Thanks for the info Lowflyer !


12-17-2005, 11:58 AM
Plenty more where that came from - stay tuned http://forums.ubi.com/images/smilies/16x16_smiley-wink.gif

12-17-2005, 03:31 PM
Hmmm€¦ I€ve always thought that the Air Ministry were very prone to faffing about with the Whirly and reading between the lines, Mr Penrose seems to concur with that supposition. Westlands were not thought of as a major aircraft manufacturer and as such were not given to having their aircraft designs getting the€ Green light€ to go straight from the drawing board to War time orders€¦ Also Mr Petter seems to be another unknown quantity in the Air Ministries eyes€¦ And although the Whirlwind was the way ahead in design of aircraft in general, it was just too much to soon for the €˜Men from the Ministry€ to back.
Funny how in the intervening years between the beginning and the end of the War their out look on what they wanted changed€¦ The De Havilland Hornet was what the Whirlwind should have been from the start, but for its Makers name and choice of engines€¦