4925th Test Group The 4925th Test Group is an inactive United States Air Force unit . Its last was assigned to the 4901st Support Wing ( Atomic ) , stationed at Kirtland AFB , New Mexico . It was inactivated on 31 August 1961 . Known as " The Megaton Blasters " , the 4925th was responsible for the development flight testing of all USAF nuclear weapon delivery systems including conducting live test drops from 1951 though 1958 . The Group was discontinued on April 1 , 1961 when Air Force Systems Command replaced Air Research and Development Command and components of its mission were distributed among other units . At least 73 personnel who served in this unit are known to have died subsequently as a result of radiation cancer . History . Established in 1948 as the 3170th Special Weapons Group following a decision to consolidate all USAF special weapons activities under AF Special Weapons Command . Was tasked with testing all aircraft in the United States inventory for nuclear weapons delivery capability . Its overall mission was specifically to : The group also recommended military characteristics and requirements for special weapons , provided facilities for training programs , and maintained an instrumentation laboratory and a technical liaison with the Air Force Special Weapons Program ( AFSWP ) , AEC , and others . The top bomber and fighter pilots in the USAF and expert support personnel were transferred to the 4925th Special Weapons Group . These included bomber , fighter , and helicopter pilots ; bombardiers ; nuclear project engineers ; depot level modification personnel ; aerial cameramen ; and crew chiefs and crews . Each had to have AEC “ Q ” clearance , a background check by the Federal Bureau of Investigation [ FBI ] that went back 15 years . The group was established within a double - barbed - wire - fence complex dubbed “ Area Charlie ” with a small sign on the gate reading “ Santa Fe Operations ” . In July 1951 , the 4925th Special Weapons Group was redesignated the 4925th Test Group ( Atomic ) and continued as an important component of KAFB ’ s nuclear responsibilities . During the early 1950s the 4925th Test Group ( Atomic ) participated in the majority of atmospheric nuclear tests , both in the Pacific and in Nevada . The group completed nuclear live drops at both the Nevada and Pacific test complexes and ballistic drops , or duplicates of the real thing , at the Edwards AFB Precision Bomb Range , the AEC Salton Sea Precision Bomb Range in southeastern California , and the Low Altitude Bombing System ( LABS ) Bomb Range near Edwards AFB . The 4925th Test Group ( Atomic ) also participated in drops at the Navy Auxiliary Air Station Bomb Range , California , Tonopah Bomb Range , Nevada , White Sands Missile Range , New Mexico ( Hardison 1990 ) , and at KAFB ’ s Practice Bomb Range on Isleta Pueblo , New Mexico . The group participated in AFSWC Development Directorate investigated projects such as adding a parachute to a bomb to delay delivery , which allowed for the combat crew to release the bomb and escape before it exploded . The goal of one of the early lay - down projects was to determine the feasibility of delivering a parachute - retarded thermonuclear weapon weighing more than 40 , 000 pounds , the heaviest nuclear weapons in the stockpile , from altitudes exceeding 40 , 000 feet . One early effort was the development of a system that could retard the fall of either a TX - 14 or a TX - 16 weapon , heavy airburst bombs , from altitudes of 40 , 000 feet to 4 , 000 feet in 167 seconds from a B - 36 Peacemaker . In 1956 , however , AFSWC was directed to establish a permanent USAF Air Task Group for atmospheric tests . Thus , in 1956 , the 4950th Test Group ( Nuclear ) was created , holding equal stature to the 4925th Test Group ( Atomic ) . At that point , the atmospheric test participation of the 4925th Test Group ( Atomic ) was cut back and the group focused on the aircraft / weapon marriage mission . The group evaluated equipment for the installation of special weapons into aircraft . This included sway braces , bomb suspension and control systems , pylons and racks , handling and loading equipment , and control and monitor apparatus . During 1956 the 4925th Test Group ( Atomic ) worked on equipment testing to provide single Mk - 15 and Mk - 21 capabilities for the B - 52 . Both configurations were in use by the end of 1956 , and successful flight and drop tests continued into February 1957 . The group also began testing the TX - 28 with the swept - wing F - 84F “ Thunderstreak . ” Aircraft modifications included pylon and weapon loading and compatibility , proper functioning of the units , clearances , and complete electrical checks of the special weapons control . Flights determined aerodynamic loads , vibration , stability and control affects in straight and level , flight dive and LABS maneuvers . A new technological innovation in the early 1950s , LABS was a component of the flight control system ; it controlled an aircraft automatically during low - altitude bombing . These test maneuvers were made at various true airspeeds , altitudes , and release and dive angles . In 1957 , AFSWC , including the 4925th Test Group ( Atomic ) , assisted the ADC with the loading of the first operational Genie rocket onto F - 89J “ Scorpion ” aircraft ( Greene et al . 1957 ) . The F - 89J was the aircraft used for the live test fire of the Genie rocket at the Nevada Test Site and became the ADC ’ s first fighter - interceptor to carry nuclear armament . Other aircraft tested by the 4925th Test Group ( Atomic ) included B - 29 , B - 50D Superfortress , B - 36H Peacemaker , B - 45 , B - 47 Stratojet , B - 57 , and B - 66 bombers . These were paired with fission and thermonuclear bombs , both established and those in development . In 1956 , the 4950th Test Group ( Nuclear ) took responsibility for the 4926th Test Squadron ( Sampling ) . In 1960 , the 4926th Test Squadron ( Sampling ) moved from the 4950th Test Group ( Nuclear ) and consolidated with other organizations into the 4925th Test Group ( Atomic ) . Inactivated in 1961 after 1958 moratorium of atmospheric nuclear testing .