The US Department of Defense unveiled a budget proposal on 4 March that would slash billions of dollars in aviation spending and make sweeping cuts to procurement of new fighter jets and unmanned aircraft.

The $495.6 billion proposal, which still must be approved by Congress, also would delay entry-into-service of Sikorsky's CH-53K heavy-lift helicopter by one year and reduce the US Air Force's fleet of Boeing F-15C fighters by 51 aircraft.

That is in addition to retiring entire fleets of ageing aircraft, such as Lockheed's U-2, Bell Helicopter OH-58D Kiowa Warriors and Fairchild Republic A-10 close air support aircraft.

The US Department of Defense's FY15 budget request calls for cuts to fighter and unmammned aircraft procurement.

TypeFY11 EnactedFY12 EnactedFY13 EnactedFY14 EnactedFY15 Request
AH-64 Remanufacture1627324225
AH-64 New-build001240
H-1 Upgrades3125302126
Manned ISR
Unmanned ISR

Officials at the Pentagon say budget cuts required by the 2011 Budget Control Act leave them no choice but to slash funding to major programmes.

The cuts are in addition to a broader strategy to modernize the US military, making it better prepared to counter high-tech threats from emerging adversaries in places like the Asia-Pacific and Middle East regions, say officials.

Although deeper budget cuts known as the sequester are scheduled to take hold in fiscal year 2016, the Pentagon's proposed budget calls for spending above sequester levels.

"We believe if we return to sequester-level cuts in [fiscal year] 2016, we will be facing significantly higher level of risk," says the Department of Defense.

The proposal calls for the Pentagon to spend $40 billion on aircraft and related systems in fiscal year 2015, down roughly 6% from last year.

Notably, the proposal includes funding for only 34 fighter aircraft, down from 50 in fiscal year 2014 and nearly 80 in fiscal year 2013.

The reduction comes from a lack of funding for additional orders of Boeing F/A-18E/F Super Hornets or E/A-18G Growler electronic attack aircraft.

Boeing has been hoping to secure additional orders it needs to keep the Super Hornet production line in St. Louis active beyond the beginning of 2016, when all current orders will be fulfilled.

The Pentagon also proposes to cut procurement of Boeing's new Poseidon P-8A anti-submarine aircraft to eight aircraft from 16 in the 2014 budget.

That move follows a 2013 programme report noting initial examples of the P-8A have limited capability because they lack broad-area search systems found on the navy's ageing fleet of upgraded Lockheed P-3C Orions.

The budget would also trim procurement of unmanned reconnaissance aircraft to 31 in fiscal year 2015 from 37 this fiscal year. That's due largely to a reduction in procurement of General Atomics MQ-9 Reapers to 12 from 20 this year.

Despite the cuts, the proposal calls for funding for 273 rotorcraft in fiscal year 2015, up from 254 in the prior period. That includes funding for 116 Sikorsky H-60 helicopters, up from 107 last year, and 55 Airbus Helicopters UH-72A Lakotas.

The budget also includes funding for new projects, including $600 million over five years for the US Air Force's T-X fighter trainer programme, which the service says will likely begin in fiscal year 2017.

The T-X is being developed to replace the service's fleet of Northrop T-38C Talon trainers.

The proposal also includes $2.4 billion over five years to recapitalise the USAF's joint surveillance target attack radar system (JSTARS) aircraft, and $337 million in fiscal year 2015 for the joint air-to-surface standoff missile (JASSM).

The Pentagon's budget will likely face scrutiny as it moves to Congress as part of President Obama's budget proposal, say analysts.

"A lot of these proposals are going to generate a lot of controversy on the Hill," says Todd Harrison from the Center for Strategic and Budgetary Assessments. "Congress is already pushing back on a number of things DOD is proposing."