The four candidates topping the national ballots next week have been taking advantage of the speed and privacy of business aviation as they crisscross the country.

Without general aviation, says a charter supplier to the Democratic ticket, “It would be an impossible chore.”

The campaigns have been facilitated using Boeing and Citation and Falcon jets, and Sikorsky helicopters. Hillary Clinton and Donald Trump fly private, as do VP candidates Tim Kaine and Mike Pence.

Mrs. Clinton shifted on Labor Day to a 737-800, on which she now carries both campaign staff and reporters. The aircraft, tail number N881XA, is registered to AerSale USA and operated by AerSale’s Xtra Airways unit.

A Falcon 900B from Executive Fliteways formerly used by the Democratic candidate is now being used by her running mate, Virginia Senator and Democratic VP candidate Tim Kaine.

Florida-based AerSale specializes in mid-life aftermarket aviation flight equipment, offering used aircraft, refurbished in-house, as an economic alternative to new jets. It claims FedEx, Taiwan’s Eva Air, the charter carrier Air Atlanta (Icelandic), Iberia Mantenimiento, Asiana Airlines, Thai among its customers, as well as NASA, for the space agency’s “Flying Laboratory” DC-8.

Coral Gables-based Xtra Airways, the former Casino Express, was acquired by AerSale’s principals in 2014. Xtra is an FAA Part 21 operator specializing in flexible and reliable lift for group air travel, “accommodating sports teams, corporate incentive groups, entertainers, civic leaders, students, or any other group” – including campaign organizations.

Xtra operates both 737-400 and, as for Mrs. Clinton, 737-800 jets.

The Democratic nominee made news earlier this year when it was reported that her campaign had spent upwards of $2 million with Executive Fliteways, where her preference was for a Falcon 900B trijet, one of the Long Island-based operator’s large jets. “This is the one place where you do buy time,” Executive Fliteways president John Grillo says of charter travel.

Donald Trump made aviation news this year as it was reported that the registration on his Cessna Citation X, tail number N725DT was allowed to lapse. The 1997 airplane had been registered to DJT Operations but ownership shifted to another Trump entity, DT Endeavor I, avoiding a potentially lengthy re-registration process.

Trump told The New York Times that re-registration notices for the Citation X were sent to the wrong address.

The Trump organization also operates his flagship 757-200 (tail number N757AF, registered to DJT Operations), which was built in 1991. The aircraft was reportedly owned by Paul Allen of Microsoft, and Trump bought it in 2011.

Trump has been pictured numerous times with Sikorsky S-76B helicopters bearing his eponymous insignia: a black (tail number N76DT) aircraft built in 1989 and registered to DJT Aerospace, and a white (tail number N76TE) machine built in 1990 and registered to DT Connect.

Reporters following Trump are flown in a 737-400, tail number N752MA, built in 1996 and brokered from Miami Air by Kansas City-based Air Charter Team. “We’re the conduit,” says Air Charter Team president Jonathan Tasler, whose company has handled aircraft for both parties’ candidates since 1999: Bush/Cheney, Kerry/Edwards, Obama/Biden and Romney/Ryan.

“My father,” Tasler says, “was flying Presidential candidates dating back to Bush/Quayle.

“We understand all the campaign issues,” Tasler says. “We’re not beholden to any one plane or operator,” he told ShowNews.

Trump running mate and Indiana Governor Mike Pence makes his rounds in a Boeing 737-800 operated by the new Eastern Airlines. The aircraft, tail number N278EA, built in 1998, can accommodate 62 passengers in an all-business layout. According to the Miami Herald, “Air Trump Two” was formerly used by the Florida Panthers hockey team.

As for the current incarnation of Eastern, the company has said it intends to eventually launch regularly scheduled flights from U.S. airports. For now, however, the airline is focused on operating charter services to Cuba and destinations in the Caribbean region.

Eastern chartered one of its Boeing 737s to Bernie Sanders during his campaign for the Democratic presidential nomination. That aircraft was brokered by Air Charter Team.

The barnstorming has all been made possible by the flexibility afforded by private aviation.

“We go into many small airports,” says Executive Fliteways’ Grillo. “There are more than 5,000 airports in the country and the airlines only fly into a few hundred of them.”

“They have demanding schedules,” he says of the political teams. “Sometimes their days are so long we have to assign another crew. Their demands were always met and that’s the way it is in private aviation.”