Junkers Ju 87 at night to drop flares and fragmentation bombs, inspired the Luftwaffe to form its own "Störkampfstaffeln" (harassment squadrons). On 23 July 1942, Junkers offered the Ju 87 B-2, R-2 and R-4s with "Flammenvernichter" ("flame eliminators"). On 10 November 1943, the RLM GL/C-E2 Division finally authorised the design in directive No. 1117. This new equipment made the Ju 87 more difficult to detect from the ground in darkness. Pilots were also asked to complete the new "Blind Flying Certificate 3", which was especially introduced for this new type of operation. Pilots were trained at night, over unfamiliar terrain, and forced to
Junkers F 13 It was the world's first all-metal passenger aircraft and Junkers' first commercial aircraft. The designation letter F stood for "Flugzeug", aircraft; it was the first Junkers aeroplane to use this system. Earlier Junkers notation labelled it J 13. Russian-built aircraft used the designation Ju 13. Like all Junkers duralumin-structured designs, from the 1918 J 7 to the 1932 Ju 46, (some 35 models), it used an aluminium alloy (duralumin) structure entirely covered with Junkers' characteristic corrugated and stressed duralumin skin. Internally, the wing was built up on nine circular cross-section duralumin spars with transverse bracing. All control surfaces were horn