Rapid Fire (BTD4-BTD5)

 is an upgrade for the Monkey Ace in the Bloons TD 4 and 5 generation allowing the Monkey Ace to shoot approximately twice as fast. The Monkey Ace also drops Pineapples much faster with this upgrade. In BTD4, its first appearance is the third tier upgrade. In BTD5 it is the first upgrade for the first path.

Costs (BTD4)

 * Easy: $595
 * Medium: $700
 * Hard: $755

Costs (BTD5)

 * Easy: $595
 * Medium: $700
 * Hard: $760
 * Impoppable: $840

Trivia

 * In BTD4, The Ace plane is an P-38 Lighting when upgraded to this, which was a plane used in World War II.
 * Rapid Fire also increases the rate in which it drops Pineapples, despite the fact that it only says that darts are shot faster.
 * Despite being the 3rd upgrade in BTD4, it became the first upgrade in each path in BTD5 and BTD6.