The Swiss Air Force mobilized on 28 August 1939, three days before Germany attacked Poland and initiated World War II, with 96 fighter and 121 observation aircraft; by some accounts the country possessed only eight antiaircraft searchlights. Of the 21 units of the Swiss Air Force, only three were judged combat-ready and five were not yet equipped with aircraft. The Air Force relied on 40 single-seat interceptors for first-line air defense. This deficiency was addressed by procuring further German Bf 109 and French
Morane D-3800 fighters. In 1942, the Swiss-built
F+W C-36 multipurpose aircraft was introduced into service, and in 1943, Switzerland opened its own aircraft factory, Flugzeugwerk Emmen. Caverns were built in which to shelter aircraft and maintenance personnel from air attack, for example in
Alpnach,
Meiringen and
Turtmann. In 1942–43, an air gunnery range at
Ebenfluh-Axalp was opened for training. The Surveillance Squadron (
Überwachungsgeschwader) was formed in 1941 and made combat-ready in 1943. A
night fighter squadron was formed for evaluation purposes in 1944 and disbanded in 1950. The role of the Swiss Air Force during World War II went through four distinct phases: • September 1939 to May 1940: Air patrol, in an attempt to enforce a comprehensive no-fly ban issued by the Swiss government to the combatants, made largely ineffective by a 5–kilometer buffer along the border which Swiss fighters were forbidden to enter. • May to June 1940: Air combat between Switzerland and Germany in which the Luftwaffe pilots tested Swiss air defenses, and were defeated. • July 1940 to October 1943: A total ban on air operations, and a release of interned German aircraft and pilots, resulting from the encirclement of Swiss territory by the Axis, the implementation of the
Réduit strategy, and recognition that the Air Force would be overwhelmed by the Germans in a sustained campaign. • October 1943 to May 1945: Resumption of air patrols, a largely passive response, measured by the numbers of intercepts versus the numbers of violations.
Defense of Swiss airspace During the first months of the war, airmen and anti-aircraft soldiers saw only sporadic combat; it was on 10 May 1940, when Germany commenced the drive into the west, that the Swiss army as a whole was mobilized a second time. At the onset of the campaign, German military aircraft first violated Swiss airspace. indigenous fighter/reconnaissance aircraft, in use from 1942 to 1952. The first serious combat involving the Swiss Air Force began in June 1940. In six days of aerial battles, eleven German aircraft were downed, with a loss of two Swiss aircraft and three airmen killed. Following these incidents, on 6 June, the chief of the
Luftwaffe,
Hermann Göring, protested the attacks, claiming that most of the German planes had been in French airspace and that the Luftwaffe had entered Swiss airspace only by mistake. Germany demanded financial compensation and an apology by the Swiss government. In a second, more pointed demand on 19 June, Germany stated that they viewed the air battles as a flagrant act of aggression, and if these interceptions continued, Switzerland would face sanctions and retaliation. The next day,
General Henri Guisan ordered all Swiss units to stop engaging foreign aircraft, and on 1 July 1940, the
Federal Council apologized for possible border violations by Swiss pilots, without admitting any had occurred. On 16 July, the German government declared that the events were settled. Engaging aircraft of the combatant nations was prohibited until October 1943, when
strategic bombing of
Bavaria and Austria by the Allies became an increasing likelihood. In September 1944, the last Swiss airman died in combat, shot down by an American
P-51 Mustang while escorting a crippled U.S.
B-17 Flying Fortress to the
Dübendorf airfield. Swiss aircraft also intercepted U.S. aircraft who were off-course, or whose crews preferred asylum in Swiss internment camps over German or Italian POW camps; they were then forced to land on Swiss airstrips. When the bombers did not cooperate or even fired at the Swiss (who were using Axis-type interceptors), they were shot down.
Night fighter incident In 1944 a Luftwaffe
Bf 110G-4 night fighter pursued a British
Lancaster heavy bomber into Swiss airspace on the night of April 28–29. Engine trouble forced the German pilot,
Wilhelm Johnen, to land at Dübendorf airfield where the pilot was interned. By international law, the Swiss had a right to put the fighter into service, and the Germans were concerned that Allied intelligence would examine its FuG 220
Lichtenstein radar and "
Schräge Musik" gun installation. The Nazi government quickly negotiated a deal in which the Swiss burned the Bf 110 under the supervision of German observers in return for a sale to the Swiss of 12 new
Bf 109G-6 Gustav to replace combat losses. The new fighters were delivered in batches of six on 20 and 22 May. The new planes had serious manufacturing defects from the poor workmanship and production disruptions caused by Allied bombings, and after complaints the Germans refunded half of the six million
Swiss franc purchase price. In 1947, the Swiss Air Force tried to purchase new replacement
Daimler-Benz DB 605 engines from Sweden, licence built by
Svenska Flygmotor AB (Swedish Aero Engines, Ltd.), but this was ruled out due to the prohibitive quoted price of 191,000 Swiss francs per engine. Such a purchase would have amounted to a total cost of over 2 million francs to re-power all 11 surviving postwar Swiss Gustav aircraft, plus the costs of spare engines, spare parts and any other repairs needed to bring them to an acceptable level of serviceability.
Attacks on Swiss cities Swiss cities and railway lines were repeatedly bombed by Allied aircraft during the war, beginning with minor attacks by the
Royal Air Force on
Geneva,
Basel, and
Zürich in 1940. In reaction to comments by Swiss Foreign Minister
Marcel Pilet-Golaz that the incident "apparently was a deliberate attack", American apologies were undermined by ill-advised statements made by Air Force commanders in London which blamed weather and minimized the size and accuracy of the attack. Although an in-depth investigation showed that weather in France, particularly winds that nearly doubled the ground speed of the U.S. bombers, did in fact cause the wing to mistake Schaffhausen for its target at
Ludwigshafen am Rhein, the Swiss were not mollified. Incidents escalated, resulting in 13 separate attacks on Swiss territory on 22 February 1945—the day President
Franklin D. Roosevelt's special assistant,
Lauchlin Currie, went to Schaffhausen to lay a wreath on the graves of those killed a year earlier—and simultaneous attacks 4 March that dropped 29 tons of high explosives and 17 tons of incendiaries on Basel and Zürich. Swiss air defenses were incapable of counteracting
large formations of aircraft, but did intercept and, on occasion attack, small groups. Since these were often aircraft crippled by battle damage and seeking asylum, resentment among Allied aircrew was considerable. The causes of the misdirected bombing attacks were bad weather, faulty equipment, incompetence, or excess pilot zeal, rather than malice or purposeful planning, but the lack of intent did not allay the sufferings and suspicions of the Swiss, and the embarrassment to the United States was considerable. A pattern of violation, diplomatic apology, reparation, and new violation ensued through much of the war, and grew in scope as Allied tactical forces neared Germany. It is still a matter of debate if these bombings occurred by accident, since U.S. strategic air forces had a standing order requiring visual identification before bombing any target within of the Swiss frontier, or if some members of the Allies wanted to punish Switzerland for their economic and industrial cooperation with Nazi Germany. In particular, Switzerland permitted train transportation through its territory carrying
matériel between Germany and Italy, which was readily visible from the air by Allied pilots. The incidents drew to a close only after a
USAAF delegation appointed by
U.S. Army Chief of Staff George C. Marshall met with the Swiss in
Geneva on 9 March 1945. The Swiss enumerated every violation since Schaffhausen and demanded full
indemnity. The Americans advised that the area requiring positive target identification was henceforth expanded to from Swiss borders, that no targets within would be attacked even in clear weather except by personal authorization from American commander General
Carl Spaatz, and then only by hand-picked crews, and that tactical air was forbidden to attack any target within of the Swiss border. Even though these restrictions provided the Germans significant protection from air attack over a large part of southern Germany for the final two months of the war, they were effective in ending the violations and did not seriously hamper Allied prosecution of the war. ==Cold War==