On 1 August, Tietzen made a forced landing 12 kilometers (7.5 miles) northeast of Gandesa.

[2] The Staffel had been created in August 1939 as the Reservestaffel (reserve squadron) of Jagdgeschwader 71 (JG 71—71st Fighter Wing).

[3] He shot down a French Bloch MB.174 bomber for his first victory of World War II on 20 April 1940.

However, on the same day, he was shot down in aerial combat with Royal Air Force Hurricane fighters over the Thames Estuary.

501 Squadron who reported two Messerschmitt Bf 109 fighters shot down between Canterbury and Westgate-on-Sea which crashed near the North Goodwin Lightship.