Eustace Grenfell Group Captain Eustace Osborne Grenfell MC , DFC , AFC ( born 26 August 1890 , date of death unknown ) was an early flying ace of World War I . He was credited with eight victories . He went on to make a career of the Royal Air Force . He was instrumental in developing the integrated radar / ground control system that won the Battle of Britain . World War I service . On 2 June 1913 , Eustace Osborne Grenfell was commissioned a second lieutenant in the Duke of Cornwall ' s Light Infantry On 9 November 1914 , he was granted Aviator ' s Certificate No . 966 after qualifying on a Maurice Farman Biplane at the Central Flying School at Upavon . On 22 December 1914 , he was appointed a Flying Officer On 17 August 1915 , he was officially seconded to the Royal Flying Corps in the rank of Lieutenant . On 5 September 1915 , he was a Lieutenant serving as a Temporary Captain and appointed a flight commander . Grenfell scored his first aerial victory on 13 September 1915 , flying a Morane - Saulnier and driving down an Albatros reconnaissance plane . He used the Morane - Saunier L , which was the world ' s first airplane built with a gun firing forward through the propeller , which was armored with metal wedges to deflect untimely bullets . Grenfell used this same crude early fighter to shoot down a second Albatros recce plane on 7 December 1915 . By January 1916 , Grenfell had upgraded to a Morane " Bullet " , as it was the weapon he wielded in a quadruple victory on the 17th . On that day , in a forty minute dogfight over the Houthoulst Forest , he drove down a Fokker Eindekker , forced another to land , put another one out of control , and drove down an Albatros two - seater . On 1 April 1916 , he was appointed a Flight Commander at the Central Flying School back in England . On 12 July 1916 , he was succeeded as an instructor by J . P . C . Cooper . Grenfell returned to battle when he was assigned to 60 Squadron , which was commanded by Alan Scott , and where he served with Albert Ball . Now using a newer fighter , a Nieuport , he drove an Albatros D . I fighter down out of control on 20 October 1916 . However , it was his last victory , on 28 December , that was the most memorable . Aided by Keith Caldwell , Henry Meintjes , and three other pilots , he forced an Albatros C . II to land in a field . Because the German plane was a new type , the victors were anxious to capture it whole for its intelligence value . They landed surrounding it , four of them crashing their Nieuports in the process . Grenfell was one of them , and the only casualty , with a broken leg . The unwounded German observer managed to set the Albatros afire ; it exploded , injuring the observer and several British infantrymen . On 19 November 1917 , Grenfell , who was a Lieutenant brevetted as a Temporary Major , reverted from Squadron Leader back to Flight Commander and Temporary Captain with seniority set back 5 September 1915 . Post World War I service . Despite his setback , Grenfell remained in the Royal Air Force . In December 1918 , he was selected as Officer Commanding of RAF Biggin Hill . Nevertheless , on 21 December 1918 , he reverted from major back to captain . His next assignment ( s ) do not appear in the record , but circa 5 April 1923 , he transferred from 27 Squadron ( India ) to 1 Squadron ( Iraq ) . On 30 June 1923 , he was promoted from Flight Lieutenant to Squadron Leader . On 1 January 1924 , he was transferred to the RAF Depot on Home Establishment . Then , while assigned to 7 Squadron , he and C F A Portal won the Laurence Minot memorial bombing trophy in September 1927 . On 1 July 1931 , he was promoted Squadron Leader to Wing Commander . On 3 August 1931 , he was transferred to RAF Gosport for admin duties . It was during this stretch that he served as a Vice Wing Commander , as he was succeeded in the position by L . M Bailey circa 17 June 1932 . On January 1933 , he was once again selected as OC of RAF Biggin Hill . This would be the most momentous assignment of his life . Beginning 4 August 1935 and extending for seven months , he was in charge of experiments in intercepting attacking enemy aircraft . The system of ground control that was developed was integrated with the brand new radar that was being developed ; that same system would be the key to British victory in the Battle of Britain and the continued existence of Britain . On 1 January 1937 , Grenfell was promoted from Wing Commander to Group Captain . He was assigned as OC of RAF Thornaby on 12 May 1938 . On 28 August 1938 , he moved on to the same post at RAF Gosport . On 17 February 1942 , he retired from the military . Honors and awards . Military Cross ( MC ) Lieutenant ( temporary Captain ) Eustace Osborne Grenfell , Royal Artillery and Royal Flying Corps . For conspicuous gallantry and skill . He attacked single - handed and brought down three Fokker aeroplanes . Captain Grenfell has shown great bravery and initiative at all times . ( Supplement to the London Gazette , 15 March 1916 ) 2877 Awarded the Air Force Cross on 2 November 1918 . Awarded the Distinguished Flying Cross on 30 May 1924 .