Disaster relief teams flying into Haiti are facing delays caused by logistical bottlenecks at the country's main airport and the country's already poor infrastructure.
The single-runway airport close to the capital, Port-au-Prince, is now a staging ground for an enormous international aid effort directed at the quake-stricken Caribbean nation.
The UN World Food Program has said severe damage at Haiti's main sea port had made ship-borne deliveries of aid impossible, leaving the small airport as the prime entry point for much-needed relief supplies.
On Thursday some 60 aid flights arrived at the Toussaint L'Ouverture International Airport, but faced a chokepoint as the first wave of planes quickly overwhelmed the single runway airport.
"There's only so much concrete... It's a constant puzzle of trying to move aircraft in and out"
US Air Force Colonel Buck Elton at Haiti's international airport
Military transport aircraft from Brazil, Canada, the Dominican Republic, France, Peru and the US jostled for space on the tarmac as helicopters from several air forces buzzed overhead.
Doctors, sniffer dogs, troops and rescue workers had to contend with airport congestion, limited jet fuel for return flights and an airport without an air traffic control tower or working radar.
The tower had collapsed when the massive 7.0 magnitude earthquake struck the Caribbean nation on Tuesday.
Arriving aircraft have also been hampered by a lack of staircases used to access the planes and allow crews to disembark.
Even teams that have managed to unload their aircraft have then had to navigate inadequate roads, sometimes blocked by debris or by quake survivors looking for safe open areas as aftershocks continued to rock the city.
Civilian flights halted
In an effort to clear the way for much-needed aid, the US Federal Aviation Administration (FAA) earlier on Thursday ordered a temporary halt on all civilian flights from the US to Haiti.
|Haiti has been overwhelmed by the extent of quake devastation [Reuters]
"There's only so much concrete" for parking planes, US Air Force Colonel Buck Elton said at the airport.
"It's a constant puzzle of trying to move aircraft in and out."
Some planes spent hours circling while awaiting permission to land, while several others were diverted to Santa Domingo in the Dominican Republic or sent back to Florida.
Flights were allowed to resume after US personnel took over air traffic control as aid groups and governments struggled to fly in planeloads of aid to the limited airfield.
Lieutenant Colonel John Dorrian, a spokesman for the Hurlburt Field Air Force Special Operations Command in Florida, said airmen had cleared runways, established 24-hour air traffic control, and had weather systems and airport lighting up and running.
Dorrian said dozens of cargo planes were taking off and landing Thursday, but damage to ramps was slowing efforts to remove cargo from the planes.
US Lieutenant Colonel Brett Nelson, deployed to Haiti to assist in the relief efforts, said flights were continuing, though there were delays.
"We are working with the FAA to establish some kind of priorities so that we get the most urgent capabilities and supplies into Port-au-Prince," he said.
Nelson told reporters that at one point on Thursday, there were 44 aircraft on the ground off-loading aid and picking up evacuees.
Red Cross officials have estimated one-third of Haiti's 9 million people are in need of aid, some of which is also passing through the border town of Jimani, in the Dominican Republic.
"Donations are coming in to the airport here, but there is not yet a system to get it in," said Kate Conradt, a spokeswoman for the Save the Children aid group.
The Brazilian military has warned aid convoys to take security with them to guard against looting by desperate survivors, saying that it was "necessary to create a structure to stock and distribute supplies".
In a move officials hope will take some strain off the overcrowded airport, a US nuclear-powered aircraft carrier has been deployed to the region to serve as a "floating airport" off Haiti.
|The US military has deployed ships and personnel to support relief efforts [AFP]
The USS Carl Vinson will use its fleet of helicopters to rush in emergency teams and vital supplies to quake victims, naval commanders said.
The carrier is outfitted with water-purifying equipment, dozens of hospital beds, three operating rooms and a giant flight deck that can accommodate numerous helicopters.
With power from two nuclear reactors and water purifying machinery, the carrier can make 400,000 gallons of drinking water a day, a vital capacity as Haiti faced a desperate need for water and food.
"You have a ship that's very ready and very flexible," Navy Lieutenant Nate Christensen told the AFP news agency.