The AN-M40 "Para-Frag" was a fragmentation bomb that was used by the United States during World War II.
The AN-M40 was quite unique in its design as a fragmentation bomb, particularly the fact that the weapon utilized a parachute in order to slow its descent and allow the aircraft dropping it to escape the harmful effects while at the same time being able to fly in low and achieve maximum accuracy. Notably, the AN-M40's standard fuse had the tendency to malfunction and thus turn the bomb into a dud, however the shear number of bombs that could be dropped at the same time meant that most attacks were extremely effective. This also counteracted the fact that each individual bomb had a relatively small explosive radius.
The bomb was most effective when attacking airfields as the fragments of the explosion would rip through aluminum air frames and kill any ground personnel present. The fuse on the AN-M40 was impact sensitive, though if it did not detonate immediately, was extremely sensitive to any further vibration. It should be noted that the designation, AN-M40 was only standardized by 1945, though the bomb had been in American usage long before then.
In order to allow for increased accuracy when using the bombs from a greater height than normal, the AN-M41 bomb was created with the addition of fins for stabilization in the air. Furthermore, a cluster-bomb variant was also created which fitted twenty-five AN-M41s into a single container and was designated the M26 Fragmentation Bomb.
The idea for the AN-M40 "Para-Frag" was first created by George Kenney in the 1920s. While the AN-M40 was not accepted for use in Europe, largely because the Allies preferred high-altitude bombardment, the large amount of Para-Frags then available were thus moved to the Pacific. The first operational use of the AN-M40 was during an air raid over Buna Airfield in Papua New Guinea in which a large air group of various attacker aircraft such as Douglas A-20s and converted P-40s dropped nearly 300 'Para-Frags' over the target with an alleged seventeen aircraft ground kills despite incredibly poor weather. After this attack, the AN-M40 was put into full operational service with units in the Pacific. Seeing the success they had, their creator, Kenney urged the conversion of as many fragmentation bombs to the Para-Frag standard as possible. In the end, thousands of fragmentation bombs had been created during the war and used in dozens of strafing attacks on Japanese airfields during the war.
- Bombardier's Information File (1945)
- Rodman, K. Matthew. A War of their Own: Bombers over the Southwest Pacific. Air University Press (2005), Page 44