U.S. regulations may exacerbate the severity of fires on cargo planes operated by carriers including FedEx Corp. and United Parcel Service Inc. and should be changed after two fatal blazes, accident investigators recommended today.
The National Transportation Safety Board, which investigates accidents and has no regulatory authority, called for mandatory fire-suppression systems in cargo planes, fire-resistant cargo containers and improved fire detection.
Current U.S. regulations allow airlines to use flammable cargo compartments that boost fires rather than suppress them, the safety board said in a recommendation letter to the Federal Aviation Administration.
“Literally, the current requirements allow a situation that feeds the fire,” Mark Rosekind, a safety board member, said in an interview.
The board’s action was prompted by investigations into three accidents since 2007 involving cargo planes carrying large quantities of lithium-based batteries used in laptop computers, digital cameras and other electronic devices. Those batteries can ignite spontaneously.
The accidents included a crash on Sept. 3, 2010, in which a Boeing Co. 747-400 operated by UPS crashed near Dubai after a fire made the jet uncontrollable, killing both pilots, according to the NTSB, which is assisting the investigation. An Asiana Airlines Inc. 747-400 went down into the China Sea on July 28, 2011, after pilots reported a cargo fire. Both pilots died.
Another UPS plane, a Boeing DC-8, was destroyed by fire on Feb. 7, 2006, after making an emergency landing in Philadelphia, according to the NTSB. The three crew members escaped.
“We’ve had three accidents in six years,” Rosekind said. “What’s significant is that they are catastrophic when they happen.”
In tests it conducted with the FAA, the NTSB found that cargo containers, which hold goods and are rolled in and out of aircraft, reduce the amount of time pilots have to save a plane after reacting to a fire.
The containers hold in smoke if an item inside is burning, delaying alerts from cargo-plane smoke detectors, according to test results on the NTSB’s website.
U.S. regulations require that smoke detectors sound an alarm within one minute. A fire within a container can burn for far longer than that before detectors sense the smoke, the NTSB found.
In one test, a fire smoldered for more than 18 minutes before it was detected.
“The growth rate of container fires after they become detectable by the aircraft’s smoke detection system can be extremely fast, precluding any mitigating action and resulting in an overwhelming fire,” the safety board said in the letter.
In addition, the containers, made of materials such as polypropylene, are “highly combustible,” the agency said.
FAA regulations forbid using flammable materials in aircraft cabins, including cargo compartments. Those standards don’t apply to cargo containers, which must meet less strict requirements, the NTSB said in the letter.
The NTSB in its letter renewed calls for fire suppression systems in all cargo compartments or in the individual containers. The FAA rejected as too costly a similar recommendation made by the safety board after the 2007 accident.
A United Nations panel earlier this year called for stricter inspections and labeling of lithium air shipments.
After manufacturers including Samsung Electronics Co. and Apple Inc. objected, Congress blocked the Department of Transportation from adopting standards stricter than those imposed by the United Nations on non-U.S. carriers.
Rosekind said the tests showed that the origin of the fire doesn’t matter if pilots don’t have enough time to land safely.
“What’s been learned is you need early detection,” he said. “The key is to have time for crews to react to what is going on and to have options.”
FedEx and UPS are developing systems that extinguish a fire or limit its spread.
UPS has built cargo containers that can stifle a fire for several hours, according to a video by the company.
“We applaud the NTSB’s goal to improve cargo fire safety,” Mike Mangeot, a UPS spokesman, said in an e-mail.
Robert Travis, president of the Independent Pilots Association, which represents UPS air crews, thanked the NTSB in an e-mailed statement.
FedEx has equipped its 64 Boeing MD-11s with an automated system that pumps fire-suppressing foam into containers if it senses too much heat, Maury Donahue, a company spokeswoman, said in an interview.
The company plans to put the equipment on all long-range aircraft that fly over oceans. Donahue called it “the right solution for the right aircraft on the right routes.”
That falls short of the NTSB’s goal of adding fire protections to all cargo aircraft.
The FAA, which must write any new cargo-fire regulations, will evaluate the recommendations, it said in an e-mailed statement.
“The FAA has long supported improved fire protection on all-cargo airplanes,” the agency said.