It will take US defense giant Lockheed Martin 18 months to clear its inventory of brand-new F-35 Lightning II fighter jets, but the company has just reached a notable but low-key milestone: Delivering the 1,000th "Lightning" stealth fighter.

The above information was shared by Lockheed's aviation division leader, Mr. Greg Ulmer, with Air & Space Forces Magazine on September 19 at the Air Force, Space & Cyberspace Conference organized by the Air Force and Space Association (AFA).

Mr. Ulmer said he could not provide a specific rate at which Lockheed is delivering the F-35s that have been stored, but said “things are going well. It will take us 12-18 months to get those aircraft and the backlog to market.”

The 18-month timeline is longer than the US Government Accountability Office (GAO) estimated in May. The Lockheed official said the delivery sequence has been approved by the company's customers.

Lockheed has declined to say exactly how many F-35s were put into storage during the delivery pause, but it is likely around 100. One of them had the honor of becoming the 1,000th fighter delivered when it was sent to the 115th Fighter Wing, a unit of the Wisconsin Air National Guard, based at Truax Field in Madison, Wisconsin, in July.

Unlike previous milestones such as the 100th F-35 produced or the 100th F-35 delivered to the US Air Force, there was no public announcement or ceremony for the 1,000th aircraft.

At the time, Lockheed Martin CEO Frank A. St. John only noted that 1,000 fighters had been delivered in an interview with CNBC, but did not specify where they had gone.

The 1,000th aircraft delivered is not necessarily the 1,000th aircraft produced. The fighters are not delivered in the order they were built, but are mixed in with new aircraft coming off the factory floor, Ulmer said. This approach is “less disruptive” to Lockheed Martin’s process of building, testing and delivering jets.

When they are put into storage, the jets are not sealed and simply parked on the tarmac, Ulmer said. Typically, each jet is inspected four times before it rolls off the production line: twice by Lockheed and twice by the customer.

The F-35 Joint Program Office (JPO) then worked with the services and foreign customers to establish the delivery sequence, the Lockheed official said. “As you can imagine, there are milestones for different customers,” he said.

Some countries are getting their first jets, such as Poland and Belgium, while “Australia wants fully operational aircraft… So these are kind of priorities that determine who gets what capability, when,” he explained, stressing that he has not heard any complaints from customers about the delivery sequence.

Minh Duc (According to Air & Space Forces)