Warplanes from the two countries are training here under an unusual arrangement while France's only aircraft carrier, the Charles de Gaulle, undergoes major renovations.

"We need to practice what it's like flying from an aircraft carrier, and any way we can do that is good," says Arnaud, a lieutenant commander from the French navy's 17F carrier air wing. He only gave his first name for security reasons.

Pilots are practicing close air support missions alongside US colleagues, as well as defensive maneuvers, aerial refuelings and other vital air skills.

The Charles de Gaulle has been out of service since early 2017 and won't be deployed again until early 2019.

So, since April 3, 350 French sailors, including 27 fighter pilots, have taken up residence on or around this base on the mouth of Chesapeake Bay, about 200 miles (320 kilometers) south of Washington.

The US Navy has loaned them a hangar where pilots train day and night on various exercises, including simulated aircraft carrier landings on a short strip of runway and simulated attacks and evasions of the F-18s.

After the land-based exercises are complete, training will continue from May 8 aboard the USS George H.W. Bush aircraft carrier.

It is extremely rare for French aircraft to land on a US ship and for such in-depth joint exercises to be conducted.

The last time was in 2008, when the Charles de Gaulle underwent a maintenance overhaul.

"What we got this far is an appetizer," said Captain Jim McCall, who heads Carrier Air Wing 8, which will train with the French aboard the Bush.

- 'Once in a lifetime' -

Aside from the 27 French pilots and their 12 Rafales, the American aircraft carrier will host French sailors representing many walks of life aboard the Charles de Gaulle, including mission trainers, mechanics and flight deck staff.

Himself a pilot, McCall said the time spent with French colleagues will allow a better understanding of how the French operate and handle their Rafales, considered the jewel of the French military.

It's a "once in a lifetime" opportunity, he told AFP.

In welcoming the French, the US military aims to strengthen interoperability between the two forces.

Ties are already close, since all French naval pilots have historically been trained in the United States. And France is the only country to have an aircraft carrier using the same landing and take-off techniques as the US Navy.

Officials hope the training will also provide the two forces with additional military options.

Training together for two months will foster knowledge that enhances combat effectiveness, McCall said. The United States and France conduct joint operations around the world including in Niger and Syria.

"Familiarity gives flexibility and flexibility gives warfighters options," he said.