Between June 1947 and October 31, 1949 the Jewish agency (later to become the Israeli government) seeking weapons for Operation Balak, made several purchases of weapons in Czechoslovakia, some of them of former German army weapons, captured by the Czechoslovak army on its national territory, or newly produced German weapons from Czechoslovakia's post-war production. In this deal, sale activities of Czechoslovak arms factories were coordinated by a special-purpose department of the Československé závody strojírenské a kovodělné, n.p. (Czechoslovak Metal-Working and Engineering Works, Nat.Ent.) Holding, called Sekretariát D (Secretariat D), headed by Gen. Jan Heřman (ret.).
The deliveries from Czechoslovakia proved important for the establishment of Israel.
Arms shipments from Czechoslovakia to Israel 1947–49 Wikipedia
The first contract was signed on January 14, 1948, by Jan Masaryk, the Czech foreign minister. Ideology played no role in these initial transaction. They were exclusively commercial. The contract included 200 MG 34 machine guns, 4,500 P 18 rifles and 50,400,000 rounds of ammunition.
Syria bought from Czechoslovakia a quantity of arms for the Arab Liberation Army but the shipment arrived in Israel due to Haganah intervention.
After the Communist coup d'état in Czechoslovakia in February 1948, military support for the nascent state of Israel increased temporarily. However, Stalin's briefly held policy of support for the state of Israel soon evaporated, and in the wake of the Tito–Stalin split, all Communist Parties had to put their foreign policy in lockstep with the Kremlin's to prove their loyalty. In this context the Czechoslovak Communists ended weapons sales to Israel. Subsequently, Stalin carried out an international purge of Communist Party officials suspected of sympathy for nationalist or Jewish variations of communism. The Communist foreign minister Vladimír Clementis, who had been the main supporter in the Czechoslovak government of the arms exports to Israel, fell victim to this purge in the Slánský trial.
The first shipment of two hundred rifles, forty MG-34 machine guns, and bullets, secretly landed during the night of 31 March–1 April at a makeshift airfield at Beit Daras in a chartered American Skymaster cargo plane. The second larger shipment, covered with onions and potatoes— of forty-five hundred rifles and two hundred machine guns, with bullets, arrived at Tel Aviv port aboard the Nora on 2 April. (A third shipment of ten thousand rifles, 1,415 machine guns, and bullets, reached the Yishuv by sea on 28 April.) At last, the Haganah command had at hand a stockpile of thousands of weapons that it could freely deploy. The two shipments proved decisive. Without doubt, of all the shipments that subsequently reached the Yishuv, none was to have greater immediate impact or historical significance."Total deliveries (confirmed until October 1948)
34,500 P-18 rifles
5,515 MG 34 machine guns with 10,000 ammo belts
10,000 vz.24 bayonets
900 vz. 37 heavy machine guns
500 vz. 27 pistols
12 ZK-383 submachine guns
10 ZK 420 semi-automatic rifles
500 vz. 26 light machine guns (shipped, yet delivery not confirmed in Czech sources)
91,500,000 7.92×57mm Mauser cartridges
15,000,000 9mm Parabellum cartridges
375,000 13mm cartridges for MG 131
150,000 20mm cartridges for MG 151
375,000 7.65mm cartridges for vz. 27 pistol
25 Avia S-199 fighters
61 Supermarine Spitfire Mk. IX fighters
Some of the aircraft were lost en route to Israel. The delivery of aircraft began on May 20, 1948, and was conducted from the Czech airfield near the town of Žatec. Some of Avia fighters were dismantled and flown to Israel in transport airplanes.
Some of the deliveries were not finished until after cessation of hostilities. Only eighteen Spitfires reached Israel prior to end of war by direct flight from Czechoslovakia during operations Velvetta 1 in September (6 planes) and Velvetta 2 in December 1948 (12 planes), both operations with a refueling stop in Yugoslavia. During operation Velvetta 2 Spitfires were repainted in Yugoslav Air Force markings for the flight from Kunovice to Nikšić. The rest were shipped in crates, officially declared as scrap iron, along with 12 Merlin 66 engines, and deliveries lasted until the end of April 1950.
Czechoslovakia also trained 81 pilots and 69 ground crew specialists, some of them later forming the first fighter unit of the Israeli Air Force, and on Czechoslovakian soil a group of Jewish volunteers the size of approximately a brigade (about 1,300 men and women) were also trained, from August 20, 1948 until November 4, 1948. The Czechoslovak Armed Force's codename of the training (mainly) was «DI» (an abbreviation from "Důvěrné Israel", literally meaning "Classified, Israel"). A Moto-Mechanized Brigade Group of Jewish volunteers trained in Czechoslovakia didn't take part in the 1948 war.