Wilde Sau Wilde Sau ( German for " wild boar " ) was the term given by the Luftwaffe , during World War II , to the technique by which British night bombers were mainly engaged by single - seat fighter planes . Origins . The originator of this operational technique was Luftwaffe officer Major Hajo Herrmann . A highly decorated bomber pilot , in early 1943 Herrmann was serving in a Luftwaffe staff position , studying operational practices and techniques , including counter - measures to the Allied bombing offensive gathering apace at the time . Implementation . In the spring of 1943 , Herrmann proposed an experimental evaluation in the use of free - ranging day fighters ( and to a lesser extent night fighter s ) at night to counter the increasingly destructive RAF night attacks . Fighter planes were not directed as in the " " Himmelbett " " ( four - poster bed ) technique using the tactical guidance of radar ground stations to the target , but rather interception was based ( after radio guidance to the general area of the bomber stream ) simply on the pilot ' s vision and own judgement ; " Wilde Sau " " wild boar " was used as opposed to the " Zahme Sau " ( " tame boar " ) method wherein an interceptor was guided by ground control . In May 1943 , the British acquired a Junkers Ju 88 R - 1 night fighter ( " Werknummer " 360043 ) when its crew defected to the Allied side and flew the aircraft to Scotland . The aircraft carried the initial " B / C " form of the UHF - band Lichtenstein radar , so its existence was revealed to the Allies ; subsequently , RAF Bomber Command were approved to deploy a new form of window or chaff ( aluminium strips ) sized to jam the Lichtenstein B / C radar . This brought about the need to deploy new night - fighting methods that no longer relied solely on AI radar until the longer wavelength , VHF - band Lichtenstein SN - 2 radar could be perfected and produced for use in German night fighters defending the Reich . To this end , fighter pilots wherever possible sought to identify and intercept enemy bombers by sight . This was to be achieved by acting against the principle of the blackout , and Herrmann proposed that the attacked city was to produce as much light as possible . Being contrary to orthodoxy , this method was resisted by the city " Gauleiter n " and not enforced . As a substitute , searchlights were used to illuminate the sky . Initial tests using former flying instructors experienced in blind - flying techniques suggested the ideal weather conditions were when a certain ( not too thick ) lower level cloud cover prevailed , since then the bomber would be silhouetted against the back - lit clouds and the high - flying German fighters could easily spot their targets . Since the " Wilde Sau " technique only worked if lighting was adequate , its application was limited to the immediate metropolitan city areas , as in most cases this was the only place where an assembly of sufficient searchlights was in place . It was therefore essential that the RAF ' s intended target was determined quickly . This was made more difficult to predict because the bomber stream often flew in a zigzag course across Reich territory . To remove the threat from their own flak , aircraft were limited to certain altitude bands . This " ceasefire " was initially only practised in the Berlin airspace , and it showed that co - ordination of fire breaks was problematic . As night - flying aids in a day fighter were rudimentary , an accordingly elaborate system of visual aids to navigation was established , encompassing light beacons , searchlight patterns , flak firing combinations of various tracer colours through the clouds , and parachute flares . The firestorm bombing of Hamburg proved disastrous for the Luftwaffe , after the Allies ' first use of window effectively knocked out the " Himmelbett " radar defence system . As a result , every other promising measure of preventing such a recurrence was considered . Hermann ' s original experimental unit was , therefore , rapidly expanded into a full " Jagdgeschwader " , " Jagdgeschwader 300 " , which used the " Wilde Sau " tactic for the first time on the night of 3 / 4 July 1943 , when 653 RAF aircraft attacked Cologne . The German fighters , taking advantage of the illumination from searchlights , target indicator flares , and ground fires , claimed 12 aircraft shot down , but had to share their claims with the antiaircraft batteries which also claimed the downings . As agreed , to avoid fratricide , antiaircraft batteries restricted the height of their flak and the fighters operated above that previously agreed ceiling . The employment of this procedure was most successful on the night of 23 / 24 August 1943 , when Berlin was attacked . The " Wilde Sau " aircraft , under the personal leadership Geschwaderkommodore Hajo Herrmann , claimed 57 aircraft brought down . Herrmann received the Oak Leaves to the Knight ' s Cross for this action . Limitations of this method of attack . If the cloud ceiling at the time of the attack were too high , restricting the lighting effect , the optical conditions were insufficient to apply " Wilde Sau " . The success of the attacks was also lost with the onset of bad winter weather in late autumn 1943 , when wastage through accidents and icing soared . German pilots were always at risk from their own antiaircraft fire . Even if " Wilde Sau " were also partly accomplished by twin - engine night fighters , the bulk of the action was carried out by conventional day fighters borrowed from the day " Jagdgeschwaders " . This double load of day and night operations and the resulting erratic maintenance schedules meant fighter serviceability rates dropped drastically . Participating units . The specially established " 30 . Jagddivision " consisting of " Jagdgeschwader " 300 , 301 and 302 , all named " Wilde Sau " , applied this technique . Also attached to 30 . JD was III . / KG 3 which was tasked to fly above the bomber stream and illuminate it with flares .