P.T.O. IV (Pacific Theater of Operations IV), released as Teitoku no Ketsudan IV (提督の決断IV) in Japan, is a World War II-themed strategy for the PlayStation 2 and PC produced by Koei. It focuses on naval combat in the maritime theaters of World War II, encompassing the Pacific Ocean, Mediterranean Sea, Atlantic Ocean, and Indian Ocean, with the option of playing as one of four major maritime powers of the time: Germany, Japan, the United Kingdom, or the United States. P.T.O. IV is the latest game in Koei's P.T.O. series.
There are two modes of gameplay: Scenario and Campaign. The former involves fighting historic naval engagements as either the attacker or defender with the option to continue in campaign mode if certain conditions are met to emerge victorious. If the player starts with the latter, the objective is to achieve victory for their chosen nation and alliance by controlling as many of the 50 regions into which the world's oceans and sea lanes are divided into as possible. Campaigns start either with the initial outbreak of World War II in September, 1939, or after the Japanese attack on Pearl Harbor in December, 1941. If the player commands the Imperial Japanese Navy, he can choose whether to attack Pearl Harbor or not.
The PTO-4 was an Estonian-designed military training aircraft of World War II.
In 1938, the Estonian aviation engineers Voldemar Post, Rein Tooma and Otto Org, previously responsible for the PON-1 trainer, designed and built the PTO-4 training aircraft. It was a two-seat low-winged monoplane powered by a De Havilland Gypsy of 120 hp, with a fixed undercarriage that could be fitted with wheels or skis. The aircraft could fly at a maximum speed of 245 km per hour and had a ceiling of 5,000 meters. On 12 October 1938, the PTO-4 was taken into service of the Air Force.
The Estonian Air Force received two PTO-4s (serial numbers 161 and 162), one with an open cockpit and the other an enclosed cockpit. Six examples were in civil use, of which five were used by the Eesti Aeroklubi (EAK), a flying club controlled by the Estonian Military.
Four examples surviving from the Soviet occupation of Estonia (1940-41) were operated by the German Luftwaffe, being operated by a unit manned by Estonian volunteers (initially called Sonderstaffel Buschmann and later 1./SAGr.127) based at Reval-Ülemiste airfield. They were operated as training and liaison aircraft as well for coastal patrol over the shores of the Baltic.
PTO may stand for: