Maj. Jennifer Grieves is the first female helicopter aircraft commander in the history of Marine One, the HMX-1 helicopter the president of the United States flies on.
Like Air Force One, the presidential plane, it is only called Marine One when the president is aboard.
"It's not really about being a female," said Grieves, 38. "It's about being a Marine and about being part of an organization that is exceptional."
There are only five Marine pilots selected at any one time to fly the president and his family.
"Of course, it's nerve wracking to fly the president of the United States," she said. "I think my most stressful days are when I fly Sasha and Malia."
Marines take no chances when flying, even on the simplest of flights. They follow the exact same protocol for every flight, no matter who is on board.
But sometimes more daunting than the passengers is the South Lawn of the White House. There are no runways to land on -- just landing disks the Marines call pucks.
"The pucks are very small that we have to land on, so it's certainly intimidating the first couple times you do it," Grieves said. "You have all the cameras on you."
Marine One has been landing on the South Lawn since 1957, when Dwight Eisenhower had to get back to the White House from Rhode Island in a hurry.
Grieves enlisted in the Marine Corps in 1990 -- almost 20 years ago. Growing up, she wanted to become a veterinarian, but once in the Marines, she was encouraged to go to college and then flight school. Grieves chose the Marine Corps because it had the most rigorous training program.
"It ended up being one of the best decisions I've ever made," she said.
Since May 2008, Grieves has traveled to seven countries, including Russia, Croatia and Great Britain, to assist the president. Most recently, she flew him in Italy.
"I went to Rome for the G-8," Grieves said. "We were there a couple weeks, and then we went directly from Rome to St. Louis so he could throw out the first pitch at the All-Star game. And then I flew my last flight the day I got back home.
"It's a very busy schedule," she added. "I would have to say I'd do it for free."
Grieves won't be earning her paycheck as a Marine One pilot any longer. Most Marine One pilots have the job for a year. She has been flying the president for the past 14 months and her last trip was this week.
To honor her, the Marines arranged for Grieves' last flight to have an all-female crew -- the first in history to ever fly the president.
"As far as the female crews go, I was so incredibly proud of both of them when we came and landed," she said. "Everything about [the flight] has probably made my Marine Corps career. And if I were to retire in six months, I would retire knowing that I've been part of an exceptional organization."
President Obama acknowledged the work she has done on behalf of her country. He came in to the cockpit of the helicopter and thanked her for her service. He also gave her a rare presidential coin.
"He told us that he was very proud of us -- and not in a condescending way, but as a military-members way, as a father-of-two-daughters way," she said. "And he just thanked us again, and it was a special moment for me."
Grieves may have been the president's pilot, but she's a Marine first.
"Obviously, meeting the president of the United States is an exceptional opportunity," she said. "But I think just being a Marine is far above that privilege."