PTAB (bomb)
PTAB (Russian ПТАБ, short for Противотанковая Авиабомба, "Antitank Aviation Bomb") was a Soviet World War II design of a Shaped Charge bomb.

Design
The bomb itself was 2.5kg with 1.5 kg of explosives. The Il-2 ground attack aircraft was capable of carrying 280 2.5 kg bombs immediately on the bomb-bay folds, or 4x48 in four cassettes. The PTAB 2.5 was capable of penetrating 60 to 70 millimeter tank armor, at the time sufficient for the top-armor of even heavy tanks.

Use
Introduced in 1943, the PTABs were widely deployed from Il-2's and also, due to the bomb's very low weight, from Yak-9 fighters, specifically from the internal weapon bay in the Yak-9b (Fighter-Bomber) modification. The Po-2 was also capable of carrying and deploying PTABs.

The number of PTABs dropped in a given time period steadily increased thereafter. By the end of 1943, Soviet records show that 1,171,340 PTABs were dropped. In 1944, the number rose to 5,024,822. In the first four months of 1945, a further 3,242,701 PTAB were used.