War against the Soviet Union

In early 1943, I. Gruppe of JG 54 was based at Krasnogvardeysk, present-day Gatchina, southwest of Leningrad, and fighting in the Siege of Leningrad in support of Army Group North. In February, the Gruppe converted from the Messerschmitt Bf 109 G-2 to the radial engine powered Focke-Wulf Fw 190 A-4 fighter aircraft.^[5] Loos claimed his first aerial victory on 19 February while fighting in the Demyansk Offensive. Assigned to 3. Staffel under command of Hauptmann Gerhard Koall, Loss shot down a Petlyakov Pe-2 bomber.^[6]

In early July, I. Gruppe of JG 54 was ordered to move to Oryol, in the southern sector of Army Group Centre, where it fought in Operation Citadel which initiated the Battle of Kursk. Subordinated to Luftflotte 6 (Air Fleet 6), the Gruppe began relocating on 2 July and arrived at the airfield named Panikowo, a makeshift airfield created for the attack on the Kursk salient, on 4 July.^[7] The next day, the Wehrmacht launched Operation Citadel and I. Gruppe supported the attack of the 9th Army on the northern sector of the salient, escorting bombers of Kampfgeschwader 4, 51 and KG 53 (KG 4, KG 51—4th, 51st Bomber Wing), as well as Junkers Ju 87 dive bombers of Sturzkampfgeschwader 1 (StG 1—1st Dive Bomber Wing) to their target areas. That day, I. Gruppe claimed 59 aerial victories, including five aircraft, three Lavochkin-Gorbunov-Gudkov LaGG-3 fighters and two Ilyushin Il-2 ground-attack aircraft, by Loos in the vicinity of Maloarkhangelsk. This achievement made him an "ace-in-a-day".^[8] Two days later, Loos claimed another Il-2 ground-attack aircraft shot down. The Il-2 belonged to 299 ShAD (Shturmovaya Aviatsionnyy Diveeziya—Ground Attack Air Division) piloted by Leytenánt A. S. Baranov.^[9]

On 20 July during the Soviet counteroffensive Operation Kutuzov, I. Gruppe relocated to Karachev.^[10] On 4 August, supporting German forces fighting at Oryol, the Gruppe claimed 25 aerial victories, including six by Loos, his second "ace-in-a-day" achievement.^[11] On 9 August, the Gruppe was ordered to an aifield named Bolschoje Rudka located near Poltava. Here the Gruppe supported German forces fighting against the Soviet Belgorod–Bogodukhov offensive operation.^[12] Here on 23 August on the final day of the Belgorod–Kharkov offensive operation, Loos achieved his third "ace-in-a-day" achievement, claiming three Douglas A-20 Havoc bombers, also known as Boston, two Pe-2 bombers and a single Il-2 ground-attack aircraft shot down.^[13] On 20 September, Loos was awarded the Honor Goblet of the Luftwaffe (Ehrenpokal der Luftwaffe).^[14] Eight days later, he was transferred to III. Gruppe of JG 54 which was fighting in Defense of the Reich.^[3]

Defense of the Reich and death

In late September 1943, III. Gruppe of JG 54 was under command of Hauptmann Siegfried Schnell and was based at Schwerin.^[15] For his 83 aerial victories claimed, Loos was awarded the German Cross in Gold (Deutsches Kreuz in Gold) on 17 October.^[14] On 2 December, the Gruppe was moved to Ludwigslust. Loos claimed his first aerial victory in Defense of the Reich on 20 December. That day, the United States Army Air Forces (USAAF) VIII Bomber Command targeted Bremen in northern Germany. III. Gruppe was scrambled at 11:10 and intercepted the bombers and their fighter escorts at 12:00 in the area of Bremen following their bomb run. In this encounter, Loos claimed a Boeing B-17 Flying Fortress bomber shot down.^[16]

Loos claimed his second B-17 bomber on 11 January 1944 when pilots of III. Gruppe claimed ten B-17 bombers and two escorting North American P-51 Mustang fighters.^[17] On 5 February, he was awarded the Knight's Cross of the Iron Cross (Ritterkreuz des Eisernen Kreuzes).^[18] Loos was promoted to Oberleutnant (first lieutenant) and appointed Staffelkapitän (squadron leader) of 9. Staffel of JG 54 on 21 February.^[14] He succeeded Oberleutnant Wilhelm Schilling who was transferred.^[19] On 6 March, Loos flying Bf 109 G-6 (Werknummer 411922—factory number) was shot down in aerial combat near Reinsehlen.^[20] His victor may have been Lieutenant John Howell of the 357th Fighter Group.^[21] Hanging on his parachute, he was drifting into a high voltage power line. Releasing the parachute at 20 meters (66 feet) he fell to his death.^[3] Loos was briefly replaced by Leutnant Alfred Kromer, who was killed only two days later. Command of 9. Staffel was then passed to Hauptmann Emil Lang.^[19]

Aerial victory claims

According to US historian David T. Zabecki, Loos was credited with 92 aerial victories.^[22] Spick also lists him with 92 aerial victories, 78 of which on the Eastern Front and 14 on the Western Front, including two four-engined heavy bombers.^[23] Mathews and Foreman, authors of Luftwaffe Aces — Biographies and Victory Claims, researched the German Federal Archives and found records for 84 aerial victory claims, all but one four-engined heavy bomber on the Eastern Front.^[24]

Victory claims were logged to a map-reference (PQ = Planquadrat), for example "PQ 36 Ost 10473". The Luftwaffe grid map (Jägermeldenetz) covered all of Europe, western Russia and North Africa and was composed of rectangles measuring 15 minutes of latitude by 30 minutes of longitude, an area of about 360 square miles (930 km²). These sectors were then subdivided into 36 smaller units to give a location area 3 km × 4 km (1.9 mi × 2.5 mi) in size.^[25]

Awards

• Iron Cross (1939) 2nd and 1st Class^[14]
• Honor Goblet of the Luftwaffe on 20 September 1943 as Leutnant and pilot^[46]
• German Cross in Gold on 17 October 1943 as Leutnant in the 1./Jagdgeschwader 54^[47]
• Knight's Cross of the Iron Cross on 5 February 1944 as Leutnant and Staffelführer of the 8./Jagdgeschwader 54^{[48][Note 6]}