Via Drudge, this story in The Intercept on the possible use of thermite as a bomb on a commercial flight is chilling. It's not that hard to construct a thermite device, although getting it by security may be difficult. And igniting the device also poses problems.

But if there's one thing we've learned about terrorists is that, although they're fanatics, they're also clever and resourceful. What has the FBI worried is that terrorists can overcome the diffuculties and bring down a plane.

The Transportation Security Administration said it is unlikely to detect and unable to extinguish what an FBI report called “the greatest potential incendiary threat to aviation,” according to a classified document obtained by The Intercept. Yet despite that warning, sources said TSA is not adequately preparing to respond to the threat.

Thermite — a mixture of rust and aluminum powder — could be used against a commercial aircraft, TSA warned in a Dec. 2014 document, marked secret [PDF here]. “The ignition of a thermite-based incendiary device on an aircraft at altitude could result in catastrophic damage and the death of every person onboard,” the advisory said.

TSA said it is unlikely to spot an easy-to-assemble thermite-based incendiary device during security screening procedures, and the use of currently available extinguishers carried on aircrafts would create a violent reaction. The TSA warning is based on FBI testing done in 2011, and a subsequent report.

A thermite device, though difficult to ignite, would “produce toxic gasses, which can act as nerve poison, as well as a thick black smoke that will significantly inhibit any potential for in-flight safety officers to address the burn.”

TSA warned federal air marshals not to use customary methods of extinguishing fires — the water or halon fire extinguishers currently found on most aircraft — which would make the reaction worse, creating toxic fumes. Instead, air marshals are told to “recognize a thermite ignition” — but TSA has provided no training or guidance on how to do so, according to multiple sources familiar with the issue.

TSA circulated these Dec. 2014 materials through briefings, according to sources familiar with the issue, but did not offer up guidance on what to do with this information, and equipment that could mitigate this threat, like specific dry chemical extinguishers, has not been provided. According to the TSA advisory, federal air marshals and other on-flight officers should: recognize a thermite ignition, advise the captain immediately, ensure the individual who ignited the device is “rendered inoperable,” and move passengers away from the affected area.

This will show you that we're in the very best of hands when relying on TSA to protect us while we're flying:

“We’re supposed to brief our [federal air marshals] to identify a thermite ignition — but they tell us nothing,” said one current TSA official, who asked not to be named because the official is not authorized to speak to the press. “So our guys are Googling, ‘What does thermite look like? How do you extinguish thermite fires?’ This is not at all helpful.”

Several aviation officials, who also asked not be named, confirmed they had been briefed on the threat, but given no information or training on identifying thermite ignition. “They say to identify something we don’t know how to identify and say there is nothing we can do,” one federal air marshal said. “So basically, we hope it’s placed somewhere it does minimal damage, but basically we’re [screwed].”

"We're screwed," does not engender confidence in the ability of TSA to do its job. The screeners are too busy looking at women's breasts and strip searching grandmas to be bothered with thermite bombs.

How big a threat is a thermite device? Some experts believe the threat is small, given the difficulty in getting the materials through the screening process, and the necessity of being able to assemble the device with no one being able to figure out what you're doing. That was the downfall of the so called, "shoe bomber" who was stopped by passengers and crew when he tried to ignite the explosive.

Still, as an exercise in juding the competence of the TSA to meet this threat, the agency falls short in almost all respects.