Aid workers fighting the Ebola outbreak on the ground in West Africa face exceedingly difficult working conditions, but now aid organizations say that simply getting them in the air has become a critical problem. Obstacles like quarantines and travel bans face many health care workers upon their return to their home countries, and it's also become difficult to arrange air travel to, from and within the countries at the heart of the epidemic.

The U.S. Agency for International Development (USAID), the federal agency overseeing the U.S. government’s response to Ebola, said that it, the U.S. military and the United Nations are taking concrete steps to provide additional air support for the effort. But some relief organizations said that assistance is not reaching them.

One American volunteer who treated Ebola patients for several weeks in Liberia with the Boone, N.C.-based Samaritan’s Purse aid group has had her trip home from the country delayed due to a lack of available flights. Her situation is far from a unique one for foreign aid workers.

“We tried booking her a ticket today and we couldn’t get a single seat for two weeks. They’re just full,” Jim Walker, deputy director for international projects at Samaritan’s Purse, said last week. “Right now Brussels Airlines has two flights every week and there’s one [Royal] Air Maroc flight occasionally. And that impacts our ability to get supplies in as well. For supplies, there’s no commercial air available. There’s only two commercial pallets per week.”

The Ebola outbreak is centered in some of the poorest and least developed countries in the world, nations with outdated airports and famously shoddy road networks. As Ebola has swept across Liberia, Sierra Leone and Guinea, the importance of air travel has only grown as thousands of doctors, nurses, support personnel, governmental workers, journalists and U.S. service members have poured into the region.

Transporting that many bodies requires many flights to, from and within the impacted countries, and they all require a constant supply of equipment to do their work once they arrive, which requires even more air capability. But numerous airlines have halted all flights to and from Monrovia, Freetown and Conakry, putting a strain on the response effort.

Within the past week, groups fighting Ebola on the ground in West Africa, including Samaritan’s Purse, the International Medical Corps and the World Health Organization (WHO), have called on the world’s governments and other organizations to help fill the gap in air travel options.

“Restrictions on air travel make it more difficult for us to move people in and out, although we’re still able to do it either through other countries or chartering flights or working with the UN mission on Ebola in Ghana. It adds expense and time when moving people and supplies,” WHO spokesman Daniel Epstein said Monday. “I think it would be nice if there was more air access to the countries affected by Ebola, both in and out. It would certainly help move people and supplies.”

USAID has heard their call and is working with the U.S. Department of Defense, the United Nations, the government of Liberia and various nongovernmental organizations to find solutions to the pressing need for additional travel options, according to USAID Disaster Assistance Response Team Leader Bill Berger.

USAID has transported more than 200 tons of supplies to West Africa since August via commercial and charter flights, and the UN Humanitarian Air Service has transported 1,130 passengers and more than 11 metric tons of cargo for 40 organizations to date, Berger said. Many of these efforts have been coordinated through a body called the “logistics cluster,” which is dedicated to handling the movement of supplies throughout the region.

“As in any country undergoing a disaster, there were initially some challenges. For example, in the early days of the Ebola response, there was limited capacity at the airport to offload planes carrying cargo to Liberia,” Berger said via email Monday. “Things have improved, with the logistics cluster acting as a venue for major international aid groups and donors to raise and address such issues. Now, additional equipment, fork lifts, etc. have been brought in and logistics operations have sped up.”

The initial Ebola response effort focused mainly on areas near the capital cities like Monrovia, but Berger said that “air transport may play a larger role in moving personnel and supplies” now that Ebola treatment centers are being built further from population centers in areas very difficult to reach by road.

Epstein said that WHO has continued to take air transport arrangements into its own hands, costing the organization money and causing logistical headaches. The head of the organization’s logistics operation said that he began chartering short roundtrip flights to transport workers to clinics within the impacted countries for $6,000, because “it was a seven- or eight-hour trip by road because the roads were so bad and they got stuck in ruts and things,” Epstein said.

Walker of Samaritan’s Purse said that he would also like to see the U.S. military get more involved with air transport in support of the Ebola efforts. “The U.S. military is helping, I’ll say, a little bit with internal flights,” he said. “The U.S. has these assets but we need to actually commit them and use them. Air would be a great asset, if they really wanted to help with the effort to help get people and supplies to Liberia and to get people home.”

There is a long history of the U.S. military providing air support in humanitarian crises such as famines in Africa, according to retired Air Force Major General Jay Lindell, a former director of logistics for U.S. Air Forces in Europe at Ramstein Air Base in Germany. “In any major disaster relief mission, the U.S., with its airlift capability provided by the Air Force, has a significant capability to help countries and quite often it is authorized to support in humanitarian disaster relief,” he said.

The Air Force is using Osprey aircraft to transport cargo within Liberia, while Blackhawk helicopters were en route last week to bolster the effort, according to a spokesman for the Air Force. As of now, however, the U.S. military is not providing air support within Guinea or Sierra Leone. The task of helping those countries falls on the rest of the global community.