"Corkscrew!"

Avro Lancaster “We Dood It Too” of 150 Sqdn RAF corkscrews violently away from a German Me 110 night-fighter which has approached from the shadowy side of its flight path. This was the classic avoiding action taken by RAF heavy bombers of World War Two when being attacked by German night-fighters. That was over 70 years ago.

Today the images and sounds are just as vivid to veterans who took part in those massive aerial assaults as they were in 1944. Bill Mann, DFC, RAAF navigator aboard “We Dood It Too”, who briefed this painting just before his passing in 2002, was one of the many Australians operating with British RAF Squadrons during the dangerous years of the massive Allied bomber offensive against Germany in the latter half of World War II. His story, like so many others, tells of the appalling game of chance that the crews indulged in every time they stepped aboard their Lancasters and Halifaxes, the four-engined bombers tasked on these operations.

Accounts of the attacking German night-fighter pilots make chilling reading – their victims often having no idea that an attacker would be in the vicinity let alone 50 metres away, which is how close Luftwaffe pilots flew to ensure the destruction of their enemy. The reason they could approach so close was that the Lancaster’s ventral gun turret, built into the original design to protect the area below and behind the aircraft, was removed so that an H2S radar dome could be installed in its place. Bomber crews were acutely aware of the weak spot and developed their own defensive tactics, such as constantly weaving to give as many pairs of eyes every chance of searching each sector. Some gunners removed the inevitably-scratched perspex clear-view panel in the rear gunner’s turret to get a clearer view of the night sky. Some even tried to keep one eye closed on exposure to ground fires, anti-aircraft shell flashes and searchlights so that night vision could be preserved in that eye at least – when desperation called for it, one eye was better than none. Some Canadian crews made a hatch aft of the H2S housing from which they could fire two Browning machine guns to protect their underbelly.

The Avro Manchester from which designer Troy Chadwick developed the Lancaster

Another hazard that they could never prepare for was when bomber crews took off they didn’t know whether or not, say, a new radar device mounted on the tail of the aircraft to give warning of an oncoming fighter, was giving out a signal on which that fighter could home-in and quickly destroy them.

One overriding characteristic of the Lancaster which crews took for granted, was the toughness of the airframe. This was fortunate because if one of the crew did manage to spot a fighter, he would call for the pilot to corkscrew left or right depending on the position of the fighter. In Bill Mann’s memory, this was no gentle manoeuvre – he talked of his aircraft being stood on its wingtip before diving away to execute a corkscrew. There were other occasions of more violent evasive actions when they twisted and turned to escape the blinding glare of one of the blue-tinged radar-controlled searchlights and the inevitable flak that would follow. Despite heavy loads imposed on it in extremis by the pilot, the big beast held together.

The ‘Lanc’ first flew in January 1941 and one of the reasons for its design success was the fact that designer Roy Chadwick based its airframe on American pioneer Jack Northrop’s stressed skin construction, first seen in the brilliant Northrop “Alpha” of 1930 and regarded by him as his most important contribution to aeronautics. Instead of relying on traditional internal bulkheads, bracing wires and struts Northrop employed pieces of rolled metal sheet, riveted together on light metal formers, producing cross-sections that had no flat areas to buckle. The result was that the “stressed” skin could then take a proportion of the load off the supporting frame while its smooth exterior created less skin friction. The resulting light, immensely strong all-metal airframe could take the ever-increasing stresses imposed by new, more powerful engines and higher speeds. The Lancaster became one of those aircraft that crews most wanted to fly. Reliable and powerful, this remarkable aeroplane was able to carry the biggest bomb load the furthest distance of any operational bomber of its time and with a lower casualty rate. None of it was possible without Jack Northrop’s genius and the skill and courage of men like Bill Mann who flew them.

An examination of the cellular pattern of rivets on the Lancaster skin, compared to those on the Northrop Alpha of 1930 confirms the Lancaster's heritage.