This post has been updated with an additional statement from the Marine Corps.

Lockheed Martin subsidiary Sikorsky Aircraft Corp. was awarded a $542 million to build six VH-92A Presidential Helicopters to mark the start of low-rate initial production, the Navy announced Monday.

“The team has efficiently leveraged a proven platform with cutting edge government mission systems for rapid agile development of the next helicopters to fly Presidential missions,” James Geurts, assistant secretary of the Navy for research, development and acquisition, said in a statement. “Optimizing commercial practices, the VH-92A will provide safe, reliable and timely transportation with mission-critical communications that will support the security of our Nation. I am proud of the combined government and contractor team who has worked so hard to transition this program into initial production and did so at over $1 billion less than the program’s cost baseline.”

The six aircraft in the award follow the three VH-92A aircraft Naval Air Systems Command have already acquired for testing. Pilots have regularly flown the test aircraft in various conditions, including practicing flying low over the National Mall and landing on the White House lawn in September.

“The Presidential lift mission is a no-fail mission for the Marine Corps,” Lt. Gen. Steven Rudder, the deputy commandant for Marine Corps aviation said in a statement to USNI News. “We deliver helicopter and MV-22 transportation across the globe to support the requirements of the Presidency. The authorization to move forward with procurement of the VH-92A will allow the Marine Corps to deliver the next generation of Presidential Helicopter support.”

In 2014, the Navy selected Sikorsky for the new Presidential Helicopter program, as part of a $1.24 billion contract award. More than a decade ago, Lockheed Martin beat out then rival Sikorsky in a 2005 competition to build Presidential helicopters. However, delays and cost overruns eventually caused the Pentagon to scrap the program and asks for new bids, according to a Congressional Research Service report. After Sikorsky won the new contract, Lockheed Martin bought Sikorsky.

The Navy expects initial operational capability for the VH-92A is scheduled to occur in late 2020, and the full production line is on track to complete in 2023.

The following is the Navy contract award to Sikorsky to build six VH-92A helicopters

Sikorsky Aircraft Corp., Stratford, Connecticut, a Lockheed Martin Co., is awarded $542,023,016 for firm-fixed price modification P00074 to a previously awarded fixed-price-incentive-firm contract (N00019-14-C-0050) in support of the Presidential Helicopter Replacement Program (VH-92A). This modification exercises an option for the procurement of six Low Rate Initial Production Lot 1 Presidential Helicopters, as well as interim contractor support, initial spares, support equipment, and system parts replenishment. Work will be performed in Stratford, Connecticut (50 percent); Coatesville, Pennsylvania (36 percent); Owego, New York (10 percent); Patuxent River, Maryland (3 percent); and Quantico, Virginia (1 percent), and is expected to be completed in April 2022. Fiscal 2019 aircraft procurement (Navy) funds in the amount of $542,023,016 will be obligated at time of award, none of which will expire at the end of the current fiscal year. The Naval Air Systems Command, Patuxent River, Maryland, is the contracting activity.