Maritime Patrol Aircraft - Armament and Countermeasures

Armament and Countermeasures

The earliest patrol aircraft carried bombs and machine guns. Between the wars the British experimented with equipping their patrol aircraft with the COW 37 mm gun. During the Second World War depth charges that could be set to detonate at a specific depth and later when in proximity with a metal object replaced "anti-submarine" bombs that detonated on contact.

Patrol aircraft also carried defensive armament which was necessary when patrolling areas close to enemy territory such as Allied operations in the Bay of Biscay targeting U-boats starting out from their base.

As a result of Allied successes with patrol aircraft against U-boats, the Germans introduced U-flak (submarines equipped with more anti-aircraft weaponry) to escort U-boats out of base and encouraged commanders to remain on the surface and fire back at attacking craft rather than trying to escape by diving. The advantage was short lived as the submarine was defenceless if it tried to dive for long enough for the aircraft to make its attack, effectively preventing it from diving until a surface ship could arrive to destroy it. Equipping submarines with radar warning equipment and the snorkel made them harder to be find.

To counter the German long range patrol aircraft which targeted merchant convoys the British introduced the CAM ship which was a merchant vessel equipped with a single fighter aircraft which could be launched once to engage the enemy aircraft. Once escort carriers became available these were converted back into conventional merchant ships.