The US Air Force has some of the most high-tech aircraft in the world flying missions at the spear's tip. But a remarkably large number of its systems are what would gently be referred to as "vintage"—and those systems are performing some of the Air Force's most important missions. One of those senior-citizen systems earned its wings during the war in Vietnam—the 48-year-old UH-1 Iroquois, also known as the "Huey".

We've reported frequently on the role that the A-10 Thunderbolt II fills for the Air Force. The 1970s-era turbofan-powered tank-killer turned close-air-support-provider-extraordinaire is constantly called upon in Afghanistan and Syria to provide firepower to protect US and allied forces. The B-52, the strategic bomber that entered service in the 1950s, has years of service still ahead of it—flying long-duration missions ranging from strategic deterrence to close air support in uncontested skies. And the land leg of the US nuclear triad, the Minuteman III ICBM, entered service in the 1960s.

But defending the US' nuclear arsenal falls in part to security forces flying the Air Force's fleet of UH-1Ns, as it has since 1970—when the last iteration of the Huey was introduced into service. Thanks to a protest and specifications no vendor could provide off the shelf, and despite Congressional backing for a replacement, the Huey may be guarding our nation's nukes for another five years at least.

In 2016, the Air Force was planning to just buy UH-60 Black Hawks straight from Lockheed Martin subsidiary Sikorsky without a contest. But the service reconsidered and put the buy up for competition in December of 2017. The Air Force's specifications aren't all public, but we know they asked for an armored helicopter capable of carrying nine troops and their gear, flying at 135 knots cruising speed for at least three hours, and a minimum range of 225 nautical miles without refueling—at the lowest possible cost. But as it turned out, not even the Blackhawks the Air Force originally wanted to buy could meet all the Air Force's requirements off-the-shelf.

Then in February, Sikorsky filed a protest over the terms of the contract put up for bid. Sikorsky's complaint was over the terms for the operations, maintenance, installation, and training (OMIT) data that would have to be provided to the Air Force, which would become government property. At the time, Sikorsky Business Development Director David Morgan told Valerie Insinna of Defense News, "The issue there is they can use that however they see fit. Give it to other services, other vendors."

The concern about "other vendors" may have been triggered by the fact that one of Sikorsky's competitors for the Huey replacement program—Sierra Nevada Corporation—entered a bid to supply refurbished Blackhawk helicopters that had already seen service with the Army. Dubbed the "Force Hawk," the Sierra entry would take retired Army UH-60 airframes and refit them with new engines and avionics. Sikorsky executives were reportedly furious over Sierra Nevada's move to sell the Air Force Sikorsky's own product.

Sikorsky's bid, on the other hand, is to provide new helicopters based on a design already sold to the Air Force for special-operations missions. The HH-60U Ghosthawk is an up-armored version of the Blackhawk equipped with surveillance sensors along with troop insertion and rescue gear. It has about 85-percent parts commonality with the HH-60W, the Air Force's current combat search and rescue helicopter.

The third contender for the Huey replacement is a collaboration between Boeing and Italy's Leonardo—the MH-139, a militarized version of the AgustaWestland AW-139 commercial helicopter. Boeing would handle the militarization of the helicopters, which would be built at a Leonardo facility in Philadelphia.

The Sikorsky protest was set aside in May. But as a result of the protest, the award of the contract has been pushed back to the end of the fiscal year, according to an Air Force spokesperson, and is in danger of missing the September 30 deadline for a buy. In a speech before the Atlantic Council on May 29, Secretary of the Air Force Heather Wilson said, "We’re going to try and not let that slip too much because we know we need to get the Hueys replaced, but we did get a delay."

The Air Force has sent Congress a reprogramming request—a request to shift budget dollars—because the program is at "high risk" of not being awarded this fiscal year. If the money doesn't get pushed into the 2019 budget, the Air Force would have to return the budget for the program and go back to Congress to re-authorize the program for the next budget year—in fiscal year 2020. That could mean that Hueys will still be flying for the Air Force until as late as 2025.

Listing image by US AIr Force