Royal Air Force A I R P O W E R REVIEW Volume 10 Number 1 Spring 2007 Relearning Air-Land Co-operation Wg Cdr Harv Smyth US Weaponization of Space Wg Cdr Johnny Stringer RAF Nuclear Deterrence in the Cold War Mr Paul Graham Legal and Moral Challenges for Today’s Air Commanders Wg Cdr Andy Myers Electronic Warfare and the Night Bomber Offensive Wg Cdr Rob O’Dell RAF Historic Book Review Gp Capt Neville Parton 96 97 Photo: RAF AHB A Boeing Fortress B Mk III electronic warfare aircraft of RAF Bomber Command To What Extent Did Royal Air Force Employment of Electronic Warfare Contribute to the Outcome of the Strategic Night Bomber Offensive of World War II? By Sqn Ldr Rob O’Dell RAF The war in the air is a technological war technical operations. In particular, the which cannot be won by a technologically night bomber offensive of World War II inferior fighting force, however high its moral saw the first intensive employment of or dauntless its resolution’ Electronic Warfare (EW), precipitating a (Luftwaffe 158 victory ace, race for technical supremacy arguably Colonel Johannes Steinhoff.2) unprecedented in the history of warfare. Introduction Many contemporary studies of the Royal During World War II offensive strategic Air Force (RAF) bomber offensive have air power evolved from principles little suggested that the campaign was of changed from the German Gotha raids little relevance to the final collapse of of World War I to highly complex and Germany. Indeed, RAF ‘area bombing’ 98 99 of German cities has sometimes been The campaign is examined in 4 stages. accused of undermining the moral Firstly, the period from September 1939 superiority of the Allies. Moreover, fuel to December 1941 saw extremely poor shortages and the loss of the Luftwaffe’s results from RAF night bombing due early warning network of radars and to unsuitable aircraft and navigation Command and Control (C2) facilities to methods, while German military advancing Allied land forces is generally expansion had emphasised offensive cited as the primary factor in the final rather than defensive operations. collapse of Germany’s night defences. Consequently, Luftwaffe night defences were ill-equipped to challenge early This essay offers an alternative RAF bomber sorties; however, the perspective that RAF employment of appointment of the inspirational EW was the most significant factor in Colonel Josef Kammhuber saw a the campaign. Bomber Command EW rapid expansion of the night-fighter allowed the RAF to limit the effects of force, enhanced by improved C2 increasingly advanced Luftwaffe C2 and Germany’s technological lead and fighter technologies, ultimately in early warning and gun-laying reducing German Air Defences (AD) to radars. Nevertheless, Britain retained virtual impotence. It is also suggested a lead in Airborne Interception (AI) that RAF navigational systems enabled technology which enabled RAF night- quantum leaps to be made in bombing fighters to challenge early Luftwaffe accuracy, given the conditions and intruder operations over Britain. technology available. Moreover, British AI radar contributed significantly to Britain’s development In reaching its conclusions, this essay of long range navigation capabilities. examines the impact of the principle Overall, the period was characterised RAF and Luftwaffe EW technologies by stalemate between the RAF and upon the strategic night bomber the Luftwaffe as they each struggled offensive against Europe during 1939- to overcome early technical and 45. The EW capabilities examined organisational limitations. include navigation, radar, passive detection, Signals Intelligence (SIGINT) The second phase, between January 1942 including Electronic Intelligence and July 1943, saw rapid developments (ELINT) and Communications by both sides. The Luftwaffe took an Intelligence (COMINT), and Radio increasing toll on RAF bombers as Counter Measures (RCM) jamming. The the so called ‘Kammhuber Line’ was significance of such systems is compared refined and Germany’s own AI radar with other factors in the campaign equipped night-fighters entered service. such as leadership, C2, and the wider However, the RAF introduced a variety strategic context of the conflict. RAF of navigation and RCM systems which studies suggested that loss rates of improved bombing accuracy and 5% over a period of 3 months reduced enabled more effective penetrations of the effectiveness of a bomber force to Luftwaffe defences. Despite innovative unacceptable levels, whilst losses of 7% German technology, further RAF tactical made a force ineffective.3 Therefore, refinements, under the leadership of the for the analytical purposes of this essay, aggressive ‘Bomber’ Harris, led to RAF RAF losses exceeding 5% are considered ascendancy during this period which unacceptable whilst those exceeding 7% included the ‘Thousand Bomber Raids’. are classed as unsustainable. Nevertheless, RAF losses were barely 98 99 sustainable and at times threatened to the most significant single factor in curtail the entire campaign. RAF victory during the night bomber campaign. The third phase commenced in July 1943 with the Battle of Hamburg. September 1939 – December 1941: This was a pivotal operation in which Stalemate RAF employment of ‘Window’ EW jamming paralyzed existing methods …only 5% of aircraft getting within 15 of Luftwaffe C2. After a brief period miles of their targets…I don’t think it where RAF losses plummeted, Window would have surprised anyone who was precipitated an overhaul of German bombing in 1941. defences and the introduction of a Bomber Command Pilot4) wide range of innovative measures which allowed a rapid recovery by Faced with the threat of German the Luftwaffe. RAF losses reached aggression, Britain had emphasised unprecedented levels in early 1944 defensive measures during its pre-war and forced the withdrawal of a third expansion. Therefore, in 1939 Bomber of Harris’ bombers from operations. Command could muster a combined Ironically, much of the Luftwaffe’s daily average of just over 200 of its success was due to passive tracking principle aircraft types, the Whitley, 5 Part of the of the navigation and EW systems Wellington and Hampden. All 3 were Chain home upon which the British crews were characterised by inadequate performance, radar system increasingly reliant. Only continued payload and RAF RCM, diversionary tactics and defensive armament. expanding Allied aircrew training and Significantly, they aircraft manufacturing programmes also lacked any form prevented RAF failure. of accurate long- range navigational From April 1944 the RAF regained system beyond the initiative from the Luftwaffe. The dead reckoning invasion of Europe and decreasing navigation supported German fuel supplies were significant by radio fixes and factors in this reversal. However, it is astro-navigation. In suggested that omnipotent RAF EW contrast, Luftwaffe and, in particular, the formation of a doctrine emphasised dedicated Bomber Command RCM the offensive tactical and intruder force ultimately proved employment of air decisive. Despite continued German power in support of technological developments during the land forces.6 Indeed, last year of the War, Luftwaffe defences Germany considered and C2 were systematically disrupted the possibility of by this RAF EW supremacy. nocturnal attacks by bombers so remote it The primacy of EW was illustrated in possessed only small June 1945 when RAF and Luftwaffe numbers of obsolete personnel evaluated Bomber Command biplanes for night- tactics during trials against the largely fighting tasks in 1939.7 intact German C2 system in Denmark. The emerging EW It is suggested that these experiments, capabilities of each against an AD system unhindered by nation reflected these Allied land forces, proved that EW was priorities. 100 101 Britain had developed the Chain Home but, lacking AI, the Bf109D proved AD radar and its associated C2 system, severely limited in the role.12 and led the world in airborne radar technology. In contrast, Germany had Following the German bombing of focused upon the offensive potential Rotterdam on 14 May 1940, Churchill of EW. The Knickebein (Crooked Leg) authorised attacks against point targets navigation system allowed accurate in mainland Germany. By 4 June 1940, ‘blind’ bombing through cloud cover. RAF bombers had flown some 1700 However, in September 1939 Germany night sorties over Germany for the loss also possessed small numbers of Freya of only 39 aircraft.13 However, without early warning and prototype Wurzburg navigation aids crews struggled to gun-laying radars, each developed in find their targets. One pilot describing complete secrecy.8 Freya had a range a bombing raid against a railway of 75 miles but could not measure an station in Dusseldorf stated that upon aircrafts altitude whilst Wurzburg reaching their target area German was a small radar with a range of 25 blackout procedures prevented them miles and an ability to plot an aircraft’s from locating the station. They then position and altitude to extremely fine conducted a fruitless ‘square search’ of limits.9 Yet despite German success the city before dropping their weapons in navigation and ground based into the darkness.14 This illustrates the radar, the Luftwaffe lagged behind problem of locating targets at night Britain in night-fighter AI technology without appropriate navigation systems and C2. German disregard of such and the impotence of German night defensive EW capabilities would later defences at the time. Furthermore,