CHARLOTTE, N.C. -- Noxious fumes in the cabin forced a US Airways flight to return to the gate at Charlotte Douglas International Airport and sent nine people to Carolinas Medical Center for treatment.
NewsChannel 36 has learned that this same plane, tail number 251, was involved in another incident in January in which 15 people were sickened by a foul odor.
Some people had respiratory problems and eye irritation, said Bob Francis of Medic, which took seven members of the crew and two passengers to Carolinas Medical Center.
The emergency room was ready when the ambulances rolled in.
There are some standard breathing treatments and drugs to relieve the pain in the throat, said CMC spokesperson Scott White. By 5:30 p.m. Tuesday, all but one of the nine people had been released, according to White.
US Airways in a statement said it was an electrical smell and said, Our first and foremost priority is the safety of our passengers and employees and we have apologized to them for the inconvenience.
The plane was headed to Montego Bay, Jamaica. All other passengers were booked on a new flight later in the day.
US Airways is still investigating the cause of the odor. A HAZMAT team did not find air contamination after the plane landed.
The Federal Aviation Administration is also looking into the incident on the Boeing 767.
Tuesday's incident involved the same aircraft on which 15 people became sick in January. Those people were treated after complaining of a foul, dirty sock type odor on-board the plane. US Airways later determined that the problems were caused by an engine oil leak. Of the seven crew members who were treated that day, only six have returned to work. All complain of illnesses they attribute to the cabin air contamination.
Maintenance logs obtained by NewsChannel 36 showed the plane was grounded due to similar complaints on Dec. 28 and Dec. 30, 2009 on flights to San Juan, Puerto Rico. Those incidents, US Airways says, were later traced back to a leak of the hydraulic fluid Skydrol in the engine.
Those fumes are transferred in to the passenger cabin by an air supply system common on commercial jets. It is standard industry practice to provide air to the cabin by compressing outside air in the plane's engine, conditioning it, and then circulating it into the body of the plane. (The air inside the cabin is also constantly recirculated.)
The plane was serviced and grounded by US Airways after each incident. It is grounded again now.
It's too early to tell what happened, said James Ray, media chairman of the United State Airline Pilots Association. This airplane has a history and we are concerned and we're monitoring it.
The USAPA and the Association of Flight Attendants had expressed concerns about US Airways tail number 251 and other planes in a letter to the airline in February. In it, union representatives wrote, It is unacceptable to expose crew members and passengers to these toxins, and it is also unacceptable to deny associated workers' compensation claims and keep passengers in the dark.
They have demanded better filtration systems on the aircraft and suggested use of a different, less toxic engine oil.
Your average passenger has no idea that the air that they're breathing is coming off the engine, Judith Murawski, a scientist with the Association of Flight Attendants, explained. Sometimes the engines leak oil and those oils are highly toxic.
Engine oil contains toxic chemicals including tricresylphosphates (TCPs) and carbon monoxide. Hydraulic fuel, while slightly less serious, also contains toxic chemicals.
There is little scientific evidence about the impacts of those chemicals on passengers and crew on the aircraft, but many people now claim they are sick. Symptoms include memory loss, tremors, headaches, and respiratory problems.
Several flight attendants have sued various airlines and even airplane manufacturers. 8 years ago, 26 flight attendants for Alaskan Air lost when they filed suit against Boeing. Passengers in Seattle and Nashville have also sued. So far, those cases have not been decided by a court.
Dr. Clement Furlong, a scientist at the University of Washington, is studying cabin air contaminations. Many of the crew members who were on board US Airways jet 251 when it experienced fluid leaks have submitted blood samples as part of his research.
(Reporter Rad Berky contributed to this report.)