months converting onto the Blenheim. In August 1939 No. 29 did convert to the Hurricane but upon the outbreak of war the squadron was reverted to the Blenheim as part of its reorientation to night fighter rather than daylight fighter operations. Braham soon earned the nickname 'Bob', which stayed with him throughout his service career. He had chosen this Christian name as his radio call sign to distinguish himself from the multitude of other Johns in the unit. Second World War Some RAF squadrons were beginning to equip with airborne radar devices. This was a pioneering technology known as airborne interception (or "AI"). It is unknown when, if, or how many of No 29 Squadron's Blenheim aircraft were fitted with them in 1940 as the squadron continued to practice, and struggle with, adapting to night-fighter tactics. A great many pilots relied on basic non-AI tactics which usually meant co-operating with search lights and using the aircrew's eyesight to seek out intruders. By the time Braham and his squadron were called upon to defend Britain from air attacks in August 1940, after the collapse of the Netherlands, Belgium and France in May–June 1940, British night fighter defences were very weak. The difficulties of night fighting was evident in the performance of the night-fighter squadrons. One Fairey Battle was shot down in error by a Blenheim which could not correctly identify the aircraft; some other Blenheims crashed after being caught in the glare of search lights at low-level and return-fire from German bombers had inflicted at least one loss whilst 29 Squadron succeeded on bring down only one German aircraft. While identification friend or foe (IFF) devices had been fitted to some British aircraft they were not always switched on. Braham also experienced technical malfunctions in the Blenheims which prompted him to call into question their reliability. On one occasion the hydraulic pipe fractured in the Blenheim he was flying which caused the landing gear to fail and prompted Braham to force-land. At this time he was joined by his gunner/observer Bill Gregory with whom he was to fly frequently. Home defence By August 1940 the Battle of Britain was intensifying. Most of the battles thus far were in daylight, leaving night-fighter crews frustrated. Now based at RAF Digby in Lincolnshire and operating from the satellite airfield at Wellingore the unit formed part of No. 12 Group RAF defending British air space