WASHINGTON — An update to the US Air Force's 2017 wish list bumps its unfunded requirements to $10.6 billion, with the service seeking funding for more F-35s and a light attack aircraft experiment, among other new efforts.

Congress has not passed a defense spending bill for 2017, opting instead to extend current funding until April — a tactic that gives the Trump administration and the Republican-controlled legislative branch time to figure out how to direct the budget for the remainder of the fiscal year. The services have responded by enlarging their own unfunded priorities lists to reflect growing demands.

In its first $7.2 billion unfunded priorities list, the Air Force restored funding for five F-35s and eight C-130Js, which had been cut in the fiscal 2017 budget request, Defense News reported in March. The new list, likely updated within the past couple months, doubles the number of F-35As the service would fund if it had money available. It also calls for 11 C-130Js, including two MC-130Js used by special operators and an HC-130J search and rescue variant.

But besides the expected procurement increases, the wish list contains a slew of new line items that reflect emerging priorities, such as $8 million for a light attack aircraft experiment that could precede a future program of record termed OA-X. Air Force Chief of Staff Gen. David Goldfein and other top officials have endorsed the flight demo as a way to test whether a buy of inexpensive aircraft can help the force ameliorate readiness challenges and affordably perform missions in permissive environments. Goldfein said in January that no money had been directed toward the experiment, but that the service would like to hold the event as early as this spring.

The service added $10 million to the list for a B-52 re-engining risk-reduction study following a January mishap at Minot Air Force Base in which a B-52 lost one of its engines during training. Although the Air Force has been considering re-engining the B-52 bomber for years, it has not been able to move out on the effort due to a lack of funds. Congress may be more willing to support this requirement given the incident earlier this year.

The Air Force wants $120 million for its Operational Control System (OCX) program, a next-generation GPS ground control station that was re-baselined this year after cost overruns triggered a Nunn-McCurdy breach and review of the program.

It also added about $63 million for EC-130H Compass Call modifications. That upgrade is required if the service moves forward with its "cross deck" strategy, which would move the Compass Call’s electronic attack systems to a new airframe.

About $51 million would go to fund manpower requirements in the new Nuclear Command, Control and Communications program office.

In addition to procuring new platforms, the service also wants funding to modernize a variety of legacy aircraft, such as $56 million for a service life extension for the B-1 bomber’s General Electric F101 engine and $57 million for various upgrades to the A-10 Warthog.

The Air Force also asks for $822 million so that fourth-generation F-16 and F-15 fighter jets would receive active electronically scanned array radars and radar warning receivers.