After hearing this Lenart quickly joined the effort to smuggle war planes into the State of Israel in early 1948. When Israel declared Independence on May 14, 1948, The Israeli Air Force consisted of just four Czech versions of German Messerschmitt. On May 29, a large Egyptian force moved within sixteen miles of Tel-Aviv, Israel. The Israelis sent all of their aircraft to intercept the force with Lenart leading the squadron. Ezer Weizman, later president of Israel, was his wing man. The Egyptians were surprised to see Israeli aircraft because they were told they had none. The Egyptians quickly retreated and Lenart was said to be the The Man who saved Tel-Aviv. Lou Lenart said it was the most important event of his life.
After the war he participated in transferring Iraqi Jews to Israel and served as a pilot for EI AI Airlines. He also served as a producer for six films. Screen writer Dan Gordon said, If it hadn't been for Lou and his three comrades, Tel Avivians would be speaking Arabic today.