The U.S. Navy awarded Boeing a $1.49 billion contract modification for a second full-rate production lot of the P-8A Poseidon maritime surveillance aircraft. The 13-aircraft order includes four Poseidons for the Royal Australian Air Force (RAAF), the first of eight P-8s that service will receive.

The contract modification the Department of Defense announced on August 27 also funds the procurement of long-lead parts for a third full-rate production lot of 20 Poseidons—16 for the U.S. Navy and four more for Australia.

With the contract award for a second full-rate production lot, the U.S. Navy’s Poseidon fleet will grow to 62 aircraft, with earlier aircraft having been ordered on a low-rate initial production basis. The service’s requirement is for 117 total aircraft.

Boeing reported delivering 28 of the 737-800 derivatives to the U.S. Navy and seven to the Indian navy. The manufacturer plans to deliver the eighth and final P-8I to the Indian navy this year.

The first Australian P-8A will enter production later this year, with delivery to the RAAF scheduled in 2016, Boeing said. Australia’s participation in the program dates to 2009 when the government signed the first in a series of memorandums of understanding to work with the U.S. Navy on system design and development. The U.S. Navy and Australian services also established a joint program office at Naval Air Station Patuxent River, Md.