Thank folks
Boulton-Paul Paladin Fighter - The Vickers Vortex Goes to WarBoulton-Paul Aircraft's P.91V
Paladin 'prototype' had been a bit of a lash-up job using the maximum number of unchanged components from the
Defiant turret fighter. The production model Boulton-Paul
Paladin was mor refined. The pilot's position was moved slightly aft to reduce heat transfer and gun gas build-up in the cockpit. Visibility from the cockpit was actually improved as a result of the Air Ministry's insistence that a standard
Spitfire windscreen and sliding hood replace the
Defiant-style glazings of the prototype.
Another obvious change was a new, lighter-weight main undercarriage. [1] Derived from
Spitfire components, this simplified, inward-retracting landing gear also created space for small, triangular auxiliary fuel tanks in the
Paladin wing centre-section. Less obvious was a switch to side-draught carburettors (which 'cleaned up' the nose profile while improving airflow to the ventral radiator bath). Armament for the
Paladin Mk.I consisted of the Vickers Class 'M' 1-inch motor-cannon trialled in N1592 as well as six wing-mounted .303-inch Browning machine guns.
The new Boulton-Paul aircraft was naturally compared with the RAF's in-service fighter types. Despite the increased power from of its
Vortex engine, the
Paladin was slightly slower than the
Merlin-powered
Spitfire Mk.IA. In theory, the new fighter was also inferior in range and endurance as well. But, superior range figures for both the
Spitfire and
Hurricane rely on those fighters flying at very slow speeds (168 mph in the case of the
Hurricane Mk.I). By contrast, quoted
Paladin range of 555 miles was based on a cruising speed of 275 mph.
Of course, the real difference with the
Paladin was its hard-hitting 1-inch main gun. That, and the fighter's endurance led to it being first adopted as a comparatively long-range bomber interceptor. Although manoeuvrable, the weight of the auto-cannon was seen as a disadvantage in fighter versus fighter combat. But that was not to be the experience of No 141 Squadron, RAF when the
Paladin Mk.I first entered service in early September 1940 - replacing that unit's
Defiants at Prestwick. No 141 was tasked with intercepting
Luftflotte 5 aircraft attacking Britain from bases in occupied Norway. In the first successful interception, a
Paladin pilot blew the entire tail off of a Heinkel bomber with one shot of his 1-inch gun.
That lucky shot would not be typical but there was no denying that the Class 'M' gun was deadly. The surprise came when No 141 began 'mixing it' with the bombers' Bf 110 escorts. With sufficient preparation time, 'vectored'
Paladin pilots found that they could tackle the twin-engined Messerschmitts head-on. A few round of 1-inch cannon fire could be loosed before coming into range of the Germans' MG-FF guns. At that point, the faster and more manoeuvrable
Paladins could disengage at will. This tactic was so successful - against escorts and bombers - that many No 141
Paladins flew with reduced wing armaments, pilots choosing to emphasize their heavy cannon instead. [2]
Paladin Mk.III - The Emergence of a True Gun-FighterIn late October 1940, No 141 Squadron moved south to join the newly re-equipped No 264 Squadron. With the Battle of Britain coming to a close, it was decided to employ the
Paladins on cross-Channel raids. Both squadrons used their 1-inch cannons to shoot up German invasion barges and other shipping moored in French Channel ports. Here the heavy guns came into their own ... but the low-flying
Paladins were usually escorted by higher-flying
Spitfires. The
Paladin pilots resented this 'nannying' but escorting
Spitfires did eliminate the element of surprise from German interceptions. Once 'bounced', the
Paladins could usually fight their way out and head for home.
A proposed all-cannon armament
Paladin Mk.II never emerged. Rather, it was the
Paladin Mk.III which brought a complete cannon armament to the breed. Wing-mounted machine guns were replaced with a pair of the new Vickers Class 'J' .75-inch auto-cannons. These potent guns fired a powerful 19 x 194mm cartridge, giving their shells the same flat trajectory as the 1-inch motor cannon rounds. The incorporation of some light alloys into the construction of the Class 'J' also meant that this gun installation actually reduced the weight of the
Paladin Mk.II as compared with its six machine gun-toting predecessor.
The
Paladin Mk.III eclipsed the proposed Mk.II, in part, because it introduced the
Vortex V powerplant. It was obvious that the
Paladin airframe would benefit from a higher-powered engine. But equally obvious was that the airframe would need more side area. Added to that was that the Vickers engines had proven hot-running - so the higher-powered
Vortex V would dictate a larger coolant radiator. Boulton-Paul solved both issues in a stroke. The ventral radiator bath was enlarged and extended aft - providing both added side area and space for enlarged glycol and oil radiators. [3]
(To be continued ...)
____________________________________
[1] The heavy
Defiant undercarriage by Lockheed had been causing problems in any case. Boulton-Paul had been investigating a replacement landing gear by Dowty even before the advent of the
Paladin.
[2] As a result of these field modifications, Boulton-Paul proposed a
Paladin Mk.IA delivered from the factory with wing armament reduced to four .303-inch machine guns. This proposal was not accepted.
[3] A less noticeable improvement was increased gas venting for the motor cannon to do a better job of keeping the cockpit clear of cordite fumes.