Originally published at 1:30 p.m.; updated at 6:32 p.m.

WASHINGTON – The Air Force is deferring 45 F-35As from its budget request over the next five years, essentially stretching out the program's planned production ramp over the next decade.

The Air Force is absorbing the biggest F-35 cut of the three services that will operate Lockheed Martin's fifth-generation fighter jet, but the Pentagon's overall buy will also drop across the five-year defense plan, comptroller Mike McCord told reporters Tuesday. The announcement comes as the Pentagon was preparing to drastically ramp up production of the aircraft over the next decade.

The reduction to 404 total Air Force, Navy and Marine Corps F-35s over the next five years is not expected to produce a significant change in the unit cost, McCord said. However, it is not clear the Pentagon will be able to get back to the planned production rate, he said.

"We are trying to get it back up to where we want it to be across the FYDP," McCord said, referring to the Future Years Defense Program. "But it's just a lot of money too, and it's unclear that we will be able to get this program back to the ramps that we had hoped for previously."

Air Force Deputy Assistant Secretary for Budget Maj. Gen. James F. Martin Jr. and Air Force Deputy for Budget Carolyn M. Gleason conduct a briefing about the FY2017 budget Tuesday afternoon at the Pentagon.

Photo Credit: Mike Morones/staff

The Air Force's official budget documents reflect a significantly slower buildup of F-35A production than previously planned. As first reported by Defense News, the Air Force deferred five F-35As this year, requesting just 43 in its fiscal 2017 budget submission, down from a planned 48. The Air Force had planned to jump to 60 F-35As a year starting in FY18, but the FY17 funding profile shows the service will not get to the 60-per-year rate until FY21. The Air Force will buy 43 aircraft in FY17; 44 in FY18; and 48 in both FY19 and FY20 before the buy jumps to 60 in FY21, according to the documents.

The delayed F-35A ramp to the ultimate goal of 1,763 aircraft is one of the "tough choices" the Air Force was forced to make in this year's budget negotiations, according to the documents. The service is partially funding Block 4 software upgrades for the jet, as well as research and development of nuclear weapons capability.

Although the Air Force cut alone is not hugely significant in the context of the thousands of aircraft the Pentagon intends to buy over the next decade, the near-term Air Force reduction could impact the unit price of the plane. Some analysts believe the deferral could have a domino effect on the program, potentially spooking international partners.

Doug Birkey, executive director of the Mitchell Institute, cautioned that the Pentagon must be extremely careful when playing with the F-35 numbers.

"The second you start bringing down numbers or you delay things, the price goes up, and so it's a risk factor," Birkey said.

Still, the Pentagon cuts over the FYDP do not necessarily indicate bad news for the overall program. Lockheed Martin can move customers around within its planned production timeline, according to Capital Alpha's Byron Callan. As the Air Force drops F-35As, international partners could fill in those slots, he pointed out in a Feb. 7 report.

Overall, the Air Force is requesting $166.9 billion in FY17, a slight uptick from the $167.9 billion requested in FY16. Included in that topline is $46.9 billion for operations and maintenance, $22.4 billion for procurement, $19.6 billion for research, development, technology and evaluation, and $12.3 billion for overseas contingency operations.

As Defense News previously reported, the Air Force's FY17 budget request fully funds the Long Range Strike Bomber and the 15-aircraft KC-46 tanker buy. The request additionally includes commitment to moving forward with the Joint Surveillance and Target Attack Radar System recapitalization effort, the Combat Rescue Helicopter, the T-X advanced trainer replacement, and the recapitalization of Air Force One. JSTARS is expected to reach initial operational capability by 2024, according to the budget documents.

The budget submission also maintains a commitment to the Long-Range Standoff Weapon, which will replace the Air-Launched Cruise Missile and is ultimately planned to arm LRSB.

Aside from F-35 delays, the Air Force is also slowing procurement of Lockheed Martin's C-130J Super Hercules transport aircraft, which will eventually replace the aging C-130Hs. The Air Force cut three C-130Js from its FY17 budget request, a drop to 11 overall: three C-130Js (including one through the OCO budget), three HC-130Js and six MC-130Js. However, the Air Force is holding onto its legacy EC-130 Compass Call aircraft, a key component of the fleet's electronic attack capability. Meanwhile, the service requested funding to recapitalize the Compass Call fleet by moving the plane's electronics onto new business jet bodies.

In another expected move, the Air Force is deferring retirement of the A-10 Warthog until 2022, and funding additional contract maintainers. The service will replace the attack plane with F-35s on a squadron-by-squadron basis to ensure commanders have sufficient aircraft to confront the threat. In the meantime, the Air Force has launched a program to upgrade the A-10 to keep it flying well into the next decade, releasing a draft statement of work on Feb. 2 for updated wings.

In modernization, the Air Force's budget request includes multiple offensive and defensive upgrades of legacy F-16 and F-15 aircraft to ensure capability and survivability in the out years, according to an Air Force spokeswoman. The FY17 budget funds F-15 C/D upgrades, which include a new Active Electronically Scanned Array (AESA) radar capability and a new Infra-Red Search and Track system, which will extend the F-15 C/D capability into the mid-2040s. Meanwhile, legacy F-16s will be equipped with a new AESA radar, as well as new electronic warfare equipment and software upgrades.

The stealthy F-22 Raptors will also receive combat capability upgrades to remain viable in contested airspace and stay ahead of acceleration threats.

The service is committed to restocking munitions expended in the fight against the Islamic State group in Iraq and Syria, requesting funds for additional Joint Direct Attack Munitions, AGM-114 Hellfires, and Small Diameter Bombs through OCO, according to the budget documents.

In intelligence, surveillance and reconnaissance (ISR), the Air Force is sticking to its plan to divest the Lockheed Martin U-2 spy plane in FY19, according to a spokeswoman. Meanwhile, the Air Force will work to upgrade Northrop Grumman's unmanned RQ-4 Global Hawk with a new sensor and payload adapter to ensure it can complete the ISR mission when the U-2 is retired.

The Air Force's FY17 budget request also continues the service's commitment to space superiority, including re-phasing the GPS space vehicle procurement from FY17 to FY18. The service has realigned the anticipated savings from the GPS III competition strategy to fund the Next Generation Operational Control System (OCX).

* The word "not" was accidentally excluded from an earlier version.

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