Aires, July 21, (AP) - Seventeen persons were killed today in the crash of an Argentine army four-engine transport plane as it took off, plunged into a crowd and burst into flames during army maneuvers at El Palomar airfield. Three of the victims, a government communique said, were civilian spectators. The other dead were military personnel and war department employes [sic]." Douglas C-54A-1-DO Skymaster, Fuerza Aérea Argentina T-44 (c/n 7463, ex-USAAF 42-107444),) could not gain altitude on takeoff. It ran through a crowd of spectators, crossed a railroad and caught fire. The airplane was to join a flight of about 200 other aircraft over the capital to celebrate the birthday of José de San Martín. 25 July The first of two North American XP-82 Twin Mustangs (44-83886, c/n 120-43742) of the 611 AAF Base Unit crash-landed at Eglin Field, Florida. 26 July Officers at NAS Los Alamitos reported that USMC 1st Lt. Leonard Smith, 25, of South Gate, California, was killed in the crash of a U.S. Navy Corsair while landing at the Seal Beach ammunition depot. There was no explosion. 29 July Nine crew were killed and two injured in a failed take-off attempt by B-29-45-MO Superfortress 44-86307, from Eglin Field in Florida, at 08:13. The bomber came down about 300 yards north of the main base near Valparaiso, Florida and burned. Killed were instructor pilot Capt. Gordon W. Barrett of Pittsfield, Massachusetts, a West Point graduate who received the DFC for flying Boeing B-29 Superfortresses in World War II; pilot 1st Lt. Huddie C. Bagley of Braufield, Texas; co-pilot Capt. Robert M. Seldomridge of Lancaster, Pennsylvania; navigator 1st Lt. Joseph A. Anderson of Shalimar, Florida; navigator 1st Lt. Milton Rose of Fort Walton, Florida; engineer Master Sgt. Michele Aulicino of Mary Esther, Florida; scanner Staff Sgt. Hugh T. Mulholland of Philadelphia, Pennsylvania; scanner Cpl. Ashley W. Odom of McBee, South Carolina, and scanner Pfc. Donald D. Crawford of Fort Worth, Texas. Injured were scanner S/Sgt. Jeremiah W. Conlon of Worthington, Kentucky (admitted to the Eglin hospital with abrasions of the face and head and ankle injuries) and radio operator S/Sgt. Lloyd D. Farris of Pensacola, Florida, with minor injuries and admitted for observation. The Superfortress apparently failed to gain altitude before coming down, said base public-relations officer Capt. Robert Gaughan. After July First prototype Gloster E.1/44 SM809, its final assembly completed in July 1947 at Bentham Experimental Department,