The morning of Wednesday 6 September 1939 brought with it a thick layer of fog that covered most of the South East of England at ground level, reducing visibility to around 10 feet. At around 6.15 AM a coastal Searchlight Battery on the Island of Mersea in the Thames Estuary reported hearing an unidentified aircraft flying overhead. The identity of this aircraft has been the subject of debate ever since with some pilots being told it may have been an RAF Bristol Blenheim, or Avro Anson. In 1954 Dowding confirmed that it had been a Dutch civilian aircraft. The thick fog on that morning would have made visual identification of this aircraft impossible, and so the Battery duly reported the detection to RAF’s 11 Group Headquarters. 11 Group decided that the detection needed to be investigated and ordered the North Weald sector commander to launch fighters to investigate. Standard procedure during these early days of the war was for RAF fighter squadrons to operate twelve aircraft, divided into two separate flights of six aircraft each, usually named ‘A’ and ‘B’ flight. These flights were further split into two sections of three aircraft each, normally coded Red, Yellow, Blue, and Green sections. The common narrative of the Battle of Barking Creek holds that 11 Group ordered only a single flight (six aircraft) to be launched to investigate the intruder, as per the standard procedure. It is told that the North Weald Sector Commander instead ordered the whole of 56 Squadron to launch, including two reserve pilots (fourteen aircraft in total), and that these aircraft were detected on radar and misidentified as enemy raiders, prompting a further response. The RAF Operations Record Books of Fighter Squadrons from 11 and 12 Groups from September 1939 tell a very different, and ultimately alarming story. The first response to the alarm was actually initiated at 6.30 AM when 151 Squadron, also based at North Weald, was ordered to launch all twelve of its Hawker Hurricanes, led by Squadron Leader “Teddy” Donaldson. 56 Squadron is recorded as having launched ten minutes later, with twelve aircraft of both flights and a further two reserve aircraft flown by Pilot Officers Frank Rose and Montagu Hulton-Harrop. Fighter Squadrons from RAF Hornchurch, around ten miles south of North Weald, became involved when 74 Squadron launched both ‘A’ and ‘B’ Flights, consisting of twelve Supermarine Spitfire Mk.1 aircraft, at 6.45 AM. These launches were only a few amongst the 116 aircraft that were sent airborne from RAF bases across the South East of England, and a further twenty-four aircraft that were readied but did not take-off. 

      With all the aircraft in the air on this bright and clear September morning, the heart of this incident was to take place between 56 and 74 Squadrons over Northern Essex. 74 Squadron’s ‘A’ Flight was being led by Flight Lieutenant Adolf ‘Sailor’ Malan with his wing-men in Red section being Flying Officer William ‘Tinky’ Measures and Sergeant Ian Douglas Hawken. The remainder of ‘A’ Flight, Yellow section, were led by Flying Officer Vincent ‘Paddy’ Byrne, with Flying Officer John Freeborn, and Sergeant John ‘Polly’ Flinders. ‘A’ Flight had flown together for some time, having formed as a dedicated unit during the latter part of the summer ‘exercises’ at Hornchurch, and the same pilots had already been called to action during the war, having been launched as a section to intercept a ‘misidentified’ friendly raid in the early hours of 4 September. As 74 Squadron flew North over Essex Malan spotted a group of aircraft ahead and called over the radio ‘Tally-Ho, Number One, Attack, Go.” Freeborn followed his section leader in a dive heading for the target, and upon approach saw unidentified aircraft in a wide ‘vic’ formation, a tactic believed to be used by Luftwaffe fighter squadrons. Byrne and Freeborn closed in and targeted a pair of aircraft flying some distance away from the main group, believing them to be Messerschmitt BF-109 fighters of the Luftwaffe, on escort duty. What they were actually targeting were the Hawker Hurricanes of Rose and Hulton-Harrop, who were slightly behind the rest of 56 Squadron. The Spitfires opened fire, Freeborn’s shots hitting the aircraft of Hulton-Harrop and striking the pilot through the back of his head, killing him instantly. Frank Rose’s aircraft was damaged by Byrne’s fire and he was able to safely crash land in a field at Wherstead, near Ipswich.  

      Freeborn and Byrne flew back to RAF Hornchurch blissfully unaware that they had shot down one of their own. Freeborn actually attempted to attack another aircraft on the way home, a twin-engined aircraft that he believed was a German Ju-88. Flinders, however, flew in front of the pilot at the last moment to halt the attack. Upon landing back at base, both Freeborn and Byrne were arrested and restricted to quarters. 19-year-old Freeborn was ‘frightened to death’ about what was to become of him. He was informed that he had caused the death of another pilot; but felt that he had simply been following the orders of his Flight Commander, Malan, and his section leader, Byrne. Despite fear over his uncertain future, Freeborn said that his Commanding Officer Squadron Leader ‘Sammy’ Sampson was incredibly supportive and arranged for him to meet Sir Patrick Hastings, a vastly experienced retired barrister who had been commissioned into RAF Fighter Command at the outbreak of war as an intelligence officer. Hastings agreed to defend both Freeborn and Byrne at a Court Martial which was scheduled for Tuesday 17 October 1939 at RAF Hendon. Another barrister, recruited as an RAF pilot at the outbreak of war, Squadron Leader Roger Bushell, would assist in the case. Bushell would become famous later in the war as ‘Big-X’, mastermind of ‘The Great Escape’ from prisoner of war camp Stalag Luft III.  

     The court martial was held ‘in-camera’, meaning it was kept under strict secrecy and not open to the general public. The official transcript of the trial has never surfaced, however newly released court martial records show that the evidence presented at the trial included accounts of lectures on aircraft recognition and the focus appeared to be on the fact that Freeborn and Byrne should have recognised that the Hurricanes were not enemy aircraft before firing. Later in his life, Freeborn recounted that ‘Sailor’ Malan was presented as a witness for the prosecution, stating that he had countermanded his original attack order over the radio once he had realised that the aircraft were friendly. Neither Freeborn nor Byrne nor any of the other pilots in 74 Squadron heard this countermanding order. Malan was called a “bare-faced liar” by Hastings and Freeborn was outraged that Malan would lie and try to cover up his own mistake. Aside from personal testimony, there was no concrete evidence against Freeborn and Byrne, and both were acquitted of all charges. The case was ruled to be an unfortunate ‘accident of war’. 

      Exactly why so many aircraft were launched on that fateful day was eventually narrowed down to an error that began at the Chain Home radar station at Canewdon, near Southend-on-Sea. Chain Home stations had been established along the entire South and East Coast of England, from Southampton to Newcastle, and were directed out to sea to provide early warning detection of incoming aircraft. Although the radio waves emanating from the radar towers went out through 360 degrees, an electronic block was activated to nullify signals coming from the rear of the sites. This block meant that RAF aircraft, flying out to meet the attackers, would not be detected on the radar screens and confuse the operators. On the morning of 6 September 1939, this electronic block had failed on the radar receiver towers at Canewdon. As soon as 151 Squadrons Hurricanes became airborne at 6.30 AM, they were detected on radar and appeared to be enemy aircraft approaching from the east. The response was to scramble more fighters, and as more launched, more ‘enemies’ appeared on the radar screens. The result was total confusion and this undoubtedly led to the pilots in the air fully expecting to see the enemy soon enough. The fault at Canewdon was supposed to have been rectified earlier in 1939 and was not detected until a week after the incident. The trouble highlighted the need for the Identification Friend or Foe (IFF) system that had been developed alongside the invention of the Chain Home radar system but was severely behind schedule in its implementation to RAF aircraft.