Concern is growing in the aviation community about potential fire hazards posed by electronic cigarettes.
In recent days, emails about the devices have swirled among airport operators in response to a fire aboard a JetBlue Airways aircraft last summer at Boston Logan International airport.
The blaze was reportedly ignited by an e-cigarette, a type of device that typically uses a lithium-ion battery to heat and vaporise a liquid containing nicotine. The process of smoking an e-cigarette is called "vaping".
Although the e-cigarette industry says the devices are safe, fire officials insist they can start fires and at least one passenger has been detained in recent days for smoking an e-cigarette during a flight.
Lithium-ion batteries, which are used on the Boeing 787, have also faced heightened scrutiny from regulators following three 787 battery fires and one battery failure since the beginning of last year.
"The recent fire aboard an aircraft we had here, caused by an e-cigarette in checked luggage, should leave no doubt in anyone's mind that these devices can absolutely start a fire," says Gerald Drumm, an official in the Massachusetts Port Authority's (Massport) fire rescue department, in a 18 September email to a fire official at the Metropolitan Washington Airports Authority (MWAA).
MWAA operates Washington Dulles and Washington National airports.
A few days later, Drumm provided more details about the blaze in an email to officials at about one dozen airport authorities across the USA, including those that operate airports in Chicago, Dallas, Denver, Miami, Salt Lake City and Seattle.
An e-cigarette zipped in a pocket of a piece of checked baggage ignited the fire, but the device's battery did not fail, says the email, obtained by Flightglobal.
"Luggage or materials apparently pushed against and remained in contact with the luggage in question, causing the push-button to activate and stay activated causing adjacent combustibles in luggage to ignite," Drumm writes.
Baggage handlers discovered the bag, removed it from the aircraft and used "handheld extinguishers to knock down the flaming bag", says Drumm.
JetBlue did not immediately respond to a request for comment.
Drumm’s email adds that users of e-cigarettes frequently modify the devices by removing safety shields intended to prevent unintended activation.
The shield on the device that started the Boston fire was missing, but Drumm says it is unclear if the shield was intentionally removed or broken during baggage handling.
He also mentions the prevalence of e-cigarettes.
"Chances are extremely likely that almost every passenger aircraft now has one or two… similar devices on board… every flight," he writes. "[There have been] several reports of e-cigarette units exploding or catching fire worldwide, especially when charging."
Among the airport officials to receive Massport's email was Lonny Craven, director of airside operations for the Miami-Dade Aviation Department, operator of Miami International airport.
Craven tells Flightglobal the message was concerning enough to prompt him to forward it to all airlines operating at Miami.
"Wow, I didn't realise this could happen," Cravis says was his response to details of the Boston fire. "This is a concern now that you have many devices probably floating around inside… baggage."
Greater awareness, he adds, should attract the attention of regulators.
Massport tells Flightglobal that it notified the Federal Aviation Administration about the incident.
The FAA and its parent organisation the Department of Transportation did not respond to questions from Flightglobal about dangers posed to aircraft by e-cigarettes.
However, the DOT notes that it is "finalising a rule that will address" whether to amend an existing smoking ban to specifically prohibit vaping on commercial flights.
DOT says new regulations could be finalised in early 2015, but adds that its existing ban against smoking on flights is "sufficiently broad" to include e-cigarettes.
Many airlines already ban in-flight vaping.
Still, there have been handful of recent reports of passengers using the devices on aircraft. For instance, news broke on 7 October that a passenger on a Tigerair aircraft was detained by Australian police after vaping on a flight from Gold Coast to Melbourne.
Despite the Boston fire, the Air Line Pilots Association (ALPA), which represents thousands of US pilots, says it "does not object to passengers carrying e-cigarettes on board a commercial aircraft".
Lithium-ion batteries do, however, pose risks when carried on aircraft as cargo, says ALPA, noting that the batteries can overheat and ignite if mishandled, overcharged or defective.
Thomas Kiklas, chief financial officer of industry group the Tobacco Vapor Electronic Cigarette Association, tells Flightglobal that e-cigarettes are safe.
Most failures occur after users modify the devices or in cases when consumers mismatch chargers with batteries – for instance, charging a 2V battery using a 4V charger, he says.
Fires caused by lithium-ion batteries in e-cigarettes are also rare and no more prevalent than fires caused by batteries in other devices, like laptop computers, adds Kiklas, who also co-owns e-cigarette brand NICMAXX.
Source: Cirium Dashboard