Wilhelm Johnen (9 October 1921 – 7 February 2002) was a German night fighter ace in the Luftwaffe during World War II.

In 1941 Johnen joined the German night fighter force (Nachtjagd) and participated in the Defence of the Reich campaign.

After infantry training Johnen spent several months practising on single-engine trainers, and qualified for his license on 21 September 1940.

On 1 February Johnen was promoted to Oberfähnrich He was subsequently sent to Zeltweg, where C-Schule prepared pilots for operations on multi-engine aircraft.

After six weeks of blind-flying training, Johnen was transferred to 3 staffel (squadron), Nachtjagdgeschwader 1 (NJG 1—Night Fighter Wing 1), together with his radio/radar operator Gefreiter Albrecht Risop.

The pair flew his first operational mission on 11 July 1941 during which they intercepted a Wellington but failed to shoot it down.

From March to July 1943 RAF Bomber Command began the campaign, dubbed the Battle of the Ruhr.

On the night of the 21/22 June 1943 Johnen claimed a Handley-Page Halifax at 01:43 east of Rousendaal (the crew of W1271 http://www.419squadron.com/W1271.html) and a Wellington northwest of Haamstede at 02:33.

Johnen scrambled with new crew members bordfunker (radar operator) Facius and his bordmechaniker (observer mechanic) Paul Mahle—whose wife lived in Berlin—scrambled to intercept at 23:00.

FuG 220 Lichtenstein SN-2 radar failed and the crew were forced to spot the enemy with the naked eye.

[10] Johnen achieved his 8th and final victory of the year on 1 September 1943 at 00:58 when he claimed a Lancaster southwest of Berlin.

This series of successes led to his promotion as Staffelkapitan (squadron leader) of 8./Nachtjagdgeschwader 6 (Night Fighter Wing 6).

35 Squadron RAF flown by Warrant Officer Bob Peter (RAAF)—he was also hit by return-fire.

[17] During the chase one of the Daimler-Benz DB 605 engines began losing oil and the coolant temperature soared.

When the flare was deployed the searchlight was momentarily turned off and Johnen headed for an illuminated airfield.

The damaged night fighter was equipped with a SN-2 Naxos radar set and Schräge Musik armament.

[21] The Germans were deeply worried about leaving a sophisticatedly equipped night fighter and these important persons in the hands of a foreign government, even if it was a neutral one.

Himmler ordered Ernst Kaltenbrunner, Chief of the Reich Security Main Office (Reichssicherheitshauptamt, RSHA) to make the necessary preparation.

He arranged an ad hoc unit at Memmingen and planned to use them to fly into the airbase in a transport from Kampfgeschwader 200 and confiscate or destroy the Bf 110.

[22] Chief of intelligence of the SS(SD) Walter Schellenberg suggested offering the Swiss 12 Messerschmitt Bf 109G-6s and manufacturing rights to them in exchange for the return of the aircraft and the crew.

Matters went awry when the German military attaché in Bern heard a rumour that a Luftwaffe officer had already inspected the machine to discover it was false after a check at the Reichsluftwaffenministerium.

[25] Johnen scored is 21st and 22nd victories at 01:17 and 01:25 south of Fels am Wagram in the early hours of the 7 July 1944.

[27] One B-24, EW165, from 34 Squadron SAAF was lost; Captain John Frederick Munro and his crew were killed and buried in Budapest.

[30] On the night of the 15/16 March 1945 Johnen shot down his 34th and final bomber, a Lancaster southeast of Würzburg at 02:45.

[31] After a brief captivity, Johnen settled to Munich and attended university, achieving an engineering degree in construction.

He also wrote his biography, Duell unter den Sternen—Tatsachenbericht eines deutschen Nachtjägers 1941–1945 (Duel under the Stars—Factual report of a German Night Fighter 1941–1945), one of the first English-written books about the Luftwaffe.

A new edition of his memoir, published by Greenhill Books, was released in February 2018 with a new introduction by James Holland.