PATUXENT RIVER, Md.–The Navy may decrease the number of Northrop Grumman [NOC]-built MQ-4C Triton unmanned aircraft it plans to buy because they have proven to be more reliable than expected and fewer may be needed to meet operational requirements, the service’s program manager for Tritons said Tuesday.

The Navy currently intends to buy 68 of the Tritons, a derivative of the Air Force’s Global Hawk, to support an operational requirement of five “orbits” of four aircraft–for a total of 20. The Navy had determined it would need 68 to maintain that requirement, but because reliability has been better than expected it may not need as many, Capt. Jim Hoke told reporters.

The Triton arriving at Naval Air Station Patuxent River, Md. Thursday. Photo: U.S. Navy
The Triton arriving at Naval Air Station Patuxent River, Md. Thursday. Photo: U.S. Navy

“The 68-buy was based on an attrition model that they cranked in at the very beginning of the program,” he said. “That’s one thing that I think will change. I think that we’ll find that these vehicles are more reliable than was initially anticipated, and so I don’t think that you are going to end up needing 68 to sustain that 20 over a period of time.”

The military typically buys more aircraft than mission requirements state to account for breakdowns and repairs as well as anticipated maintenance. Hoke said it was too early to determine a potential size of the reduction because more flight testing data and evaluation is needed. He emphasized that the program of record remains 68.

“As we continue to flight test we’ll have a better understanding of what the performance of the air vehicle is, about the performance of the system, and we’ll continue to evaluate that every year…to understand what the requirement is to sustain that 20,” he said.

The Navy is buying two test aircraft in addition to the currently planned 68, the first of which arrived here last week, where the Navy will be integrating and testing radar on other sensors for carrying out maritime intelligence, reconnaissance and surveillance missions. Two more–one owned by Northrop Grumman–are due to arrive by the end of October, Hoke said.

The Triton landed on Thursday after more than a week of delays due to weather. Flight envelope testing has been taking place at Northrop Grumman’s production facility in Palmdale, Calif. Two additional Tritons are under contract for the demonstration phase of the program, and Hoke said the Navy will soon initiate plans to move toward low-rate initial-production (LRIP). He said the number of planes ordered in the first LRIP run will be determined by the 2016 budget process.

Naval Air Systems Command, which is based at NAS Patuxent River, will be installing the sensor equipment by December with plans to start flying in early 2015, said Hoke, who plans to retire by the end of this year.

The Navy hopes to put the aircraft into early operational capability by the end of 2017 and hit initial operational capability six months later, Hoke said.

The Navy is still trying to cope with significant problems in the development of a sense-and-avoid radar system, a problem Hoke acknowledged will impact the ability of the planes to operate in national and international airspace.

Northrop Grumman’s subcontractor for the radar meant to prevent collisions with other aircraft, Exelis [XLS], has struggled to overcome some of the technical challenges. The Navy originally intended to have the radar on the first aircraft, but it probably won’t be ready until 2020, Hoke said.

Hoke said the Navy is working with domestic and international aviation authorities to determine how the Triton will operate without the avoidance radar.

The Navy plans to operate the Tritons in conjunction with the manned P-8A Poseidons built by Boeing [BA]. The Navy eventually envisions have the option of P-8A crew taking control of the aircraft during missions, but the service has not yet put money into achieving that goal, Hoke said, adding the Poseidons would have to be configured to operate Tritons.