A memo from the U.S. Airline Pilots Association, representing over 5,000 pilots who fly for US Airways, said there has been:
"several cases recently throughout the (airline) industry of what appear to be probes, or dry runs, to test our procedures and reaction to an in-flight threat."
"Bringing down an airliner continues to be the Gold Standard of terrorism," states the undated memo, first reported by WTSP-TVin Tampa-St. Petersburg. "If anyone thinks that our enemies have “been there, done that” and are not targeting U.S. commercial aviation -- think again."
The latest incident occurred on September 2, 2013, and the memo says a, "Middle Eastern" man rose from his seat and sprinted toward the cockpit at the front of the plane. He then veered off and went into a forward restroom. At that time, a group of men rose and began moving around cabin, changing seats and going into the overhead storage bins."
The Transportation Security Administration (TSA) and the airline are confirming the incident did take place. Michelle Mohr, a spokeswoman for US Airways, said four passengers were detained and questioned by local law enforcement authorities due to "suspicious behavior" during the flight.
The TSA is saying the incident was thoroughly checked out. TSA spokesman Ross Feinstein said in a statement,
“Working collaboratively with local law enforcement, it was determined that the matter required no further investigation at this time. Additionally, due to the critical mission of TSA’s Office of Law Enforcement, TSA does not confirm the presence or identity of Federal Air Marshals.”
The memo also cited another incident, on a return flight with the same flight number, 1880, where a number of women boarded the plane, all wearing burkas. An inspection of the plane showed "evidence of tampering," was found, though no details were given.
Authorities are speculating that there is the possibility that terrorist groups are "sizing up" the airline's security measures and the seating of air marshals. Experts are saying these incidents could very well indicate a possible attempt to detonate a bomb aboard a plane while in flight.
Rep. John Mica, R-Fla, is taking the incidents very seriously. He has called for a formal investigation into the incidents. Mica said in a statement,
“It is government’s obligation and responsibility to remain vigilant. While the specifics of the US Air incident are not public, federal authorities must review the matter.”