Cabin Security: Keeping Aircraft Safe

By Charlotte Adams and David Jensen | December 1, 2001
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Not surprisingly, since Sept. 11, after terrorists crashed hijacked aircraft into the World Trade Center and the Pentagon, aerospace electronics companies have come forward with new security systems for commercial airliners. Many solutions are to complement the installation of impenetrable doors separating the cockpit and cabin. Though isolated, pilots must still be aware of disruptive activity in the cabin. Among the proposed security schemes from the avionics community, cabin surveillance systems are perhaps most prominent.

Avionics Magazine has compiled a rundown of some of the new systems proposed. They include cabin surveillance systems, as well as concepts for improved voice and data communications continuity, security and survivability.


Honeywell offers perhaps the widest range of aircraft security technologies. Its new security initiative provides a single point of contact, bringing together technologies from diverse company businesses. The following capabilities could be offered in the near and longer term.


  • Cabin video/audio–Honeywell envisions a video system using covert wireless cameras, viewable on existing displays.

  • Open mic–This concept would allow the area mic in the cockpit or a covert mic to be opened if the aircraft is put into an alert state.

  • Uninterruptible data link for flight data and cockpit audio–Audio data could be transmitted via telephone or satcom.

  • Mode-S transponders that cannot be disabled–Honeywell proposes a software modification.

  • Mode-S transponders for all aircraft–These would transmit aircraft identification, speed, differential Global Positioning System (GPS) position and other information to ground authorities.

  • Dual, combined flight data/cockpit voice recorders, increasing the probability of data recovery.

  • Video-based aircraft docking and ramp surveillance system.


  • Enhanced Ground Proximity Warning System–With its database of manmade obstacles over 100 feet high, EGPWS could be used as part of a system to automatically lead a plane away from an obstacle. The one-minute impact warning time also could be extended. This solution would require a fly-by-wire aircraft with "envelope protection capability."

  • Crash-survivable video recorders–Honeywell has developed prototype survivable video recorders, citing industry interest in cockpit video.

  • Aircraft wire tamper monitors.

  • Encryption of communications transmissions.

  • Flight data and cockpit voice recorders that could be jettisoned on impact.

  • Fingerprint readers and iris scanners to positively identify flight crew and passengers.

Near-term changes to the transponders, the open mic concept and the transmitting down of flight and cockpit data would "require some modifications to existing systems, which would require FAA [Federal Aviation Administration] approval," says Frank Daly, Honeywell’s president, air transport, and security initiative leader. But the changes would be fairly minor: "We’re not talking about structural [changes] or major new equipment."

While a transponder software change "shouldn’t cost very much," there are design, test and logistics issues, says Ben Mcleod, Honeywell’s director of business development for airlines and avionics products. Airlines also may want to replace existing circuit breakers with ones that can’t be pulled manually by the crew or remove the circuit breakers to some location outside of the flight deck, he says.

Daly says Honeywell is "not vigorously pursuing [the concept of] flying the aircraft from the ground." There are many practical considerations that make the concept "fairly unlikely" any time soon. For example, how is the plane to be stopped once it is landed? The concept would only be possible on fly-by-wire aircraft, he adds.


Installation-kit provider Airworks Inc., in Rancho Santa Margarita, Calif., has developed an expandable cabin surveillance system. "Our system can cost from $15,000 on up to $100,000, depending on your recording system," says Ricky Frick, Airworks’ president and chief executive officer, of a system called SOS (Surveillance, Operational actions and Safety).

The less expensive systems might provide cameras and a liquid crystal display (LCD) monitor in the cockpit, while the pricier systems could have video recorders and even a video link to ground facilities, according to Frick. The package also could include cameras in the baggage hold for early fire detection and a crew alerting system.

Most of Airworks’ surveillance systems can be installed during an overnight layover, says Frick, so there would be no loss of revenue. No structural modifications would be necessary; installations require only the owner/operator approval form 337.

The company president suggests a cabin configuration that includes decoy cameras that can be seen and real cameras that are hidden. The former would indicate to passengers that the cabin is monitored and the latter would assure that a passenger could not find and destroy all cameras.

The real camera system could include a portable, wireless camera that transmits its video signal to the cockpit via a local area network (LAN). Most camera units, however, would be connected to the cockpit monitor by wire, and the cameras would tap their power from various existing sources, such as cabin lighting, says Frick.

"We suggest cameras requiring 28 volts DC," he adds.

The Securaplane Team

Meanwhile, Securaplane has collaborated with Garden Grove, Calif.-based Hollingsead International and Austin, Texas-based DAC International to develop and market the Cabin Alert and Monitoring System (CAMS). Comparable to the Airworks SOS, CAMS includes Securaplane’s low-power, low-light sensitive camera units with a charge-coupled device (CCD), a wireless crew alerting system and an infrared light source. With the CCD, the camera unit takes in some infrared imagery, according to Richard Lukso, president of Securaplane. But, when the light becomes too dim for image recording, a light sensor triggers infrared diodes. To the human eye, the light level appears dim, but the cameras view a fully lit cabin. The FAA already has approved the camera units and the intra-aircraft wireless communication system, says Lukso, who was interviewed on NBC’s "Dateline" television program on Sept. 16 to discuss aircraft cabin security.

Like Airworks, the Securaplane team has suggested surveillance packages of various sizes and levels of complexity. "A basic system for a narrowbody would simply be a camera on the other side of the door to the cockpit," says Mike Neder, director of airline sales for DAC International. "But we suggest at least four video cameras for narrowbodies and more for widebodies."

Flight attendants could be furnished small, spread spectrum transmitters to alert the flight crew–the type of transmitters Securaplane developed for its smoke detection system, according to Lukso. The transmitter’s signal would be captured by a receiver that is hard-wired to the annunciator panel. "When an annunciator light illuminates, one of the crewmen could then turn to his monitor display and activate the camera system," says Neder.

Airlines could select various sized cockpit displays for their CAMS systems, he adds. Securaplane offers a basic 6.4-inch (16-cm) diagonal LCD screen. The screen would be menu-driven, so the pilot could pull up images from multiple cameras.

To make CAMS a turnkey package, Securaplane has teamed with Hollingsead, which is developing the installation kit and providing systems integration and certification. Team member DAC International provides a technical marketing staff that is "well-versed" in the air transport market. This alliance is not new; Securaplane, DAC International and Hollingsead joined some five years ago to develop, sell and install smoke detection systems. The team has sold some 550 smoke detection systems.

Regarding a downlink, Lukso says Securaplane hasn’t received a request for it but could include that feature in the CAMS system.

Securaplane recently announced plans to acquire Ball Aerospace’s airborne video product line. However, the Ball products are for aircraft ground maneuvering and in-flight entertainment and were not part of the company’s decision to develop cabin surveillance equipment.

Tecstar Demo Systems

Another company that plans to offer equipment already approved for cabin surveillance is Tecstar Demo Systems, Moorpark, Calif. Called the Monitored Video Surveillance System (MVSS), this security measure, too, would have cameras and microphones hidden throughout the aircraft cabin and supplemental illumination to record in low-light conditions.

Monitoring devices would be linked to a file server located in the avionics bay. The server would be certified to the ARINC 763 specification and would combine ARINC 429 and 717 interfaces, as well as a high-speed Ethernet switch. It would use 20-gigabyte hard drive storage for video and audio. The server’s memory also would be used to store flight management and quick access recorder (QAR) data.

The MVSS server would interface with a "video concentrator" which condenses video signals. The data could be stored in the server or transmitted to the satellites over a narrowband link. It would interface with low earth orbit (LEO) GlobalStar or Iridium satellite communication systems to deliver real-time information to the ground for monitoring. Using the LEO satellites would allow the installation of a small antenna that could be hidden beneath the vertical fin cap.

The data transmission would be activated by a crew member, the aircraft’s dramatic deviation from the flight plan stored in the flight management system, or by an uplinked signal, via the satcom, from the local Terminal Radar Approach Control (TRACON). Ground personnel also could command the MVSS server to replay recorded data.

Sept. 11 has encouraged other companies to develop security systems for airlines. For example, Thales Avionics Inflight Systems introduced at the World Airline Entertainment Association (WAEA) conference a day-night security camera system, which includes color cameras with monochrome infrared sensitivity, cockpit monitor and cable accessories. The cameras are protected and hidden from view. Customer trial use of the system will begin in early 2002. Currently, four certified models of the system are available; they apply to the B767, B747, B777 and Airbus 320 aircraft types.

Also, Aero Products, a business unit of Northrop Grumman’s Navigation Systems Division, is developing a video monitoring system that is based on the CommandVu-410 display system. It would allow selectable inputs from the cockpit for both color video and infrared imagery in the cabin. A company spokesman says Aero Products would utilize proven infrared and color camera manufacturers and suppliers.

The Air Rage Factor

Some security systems being proposed since the Sept. 11 tragedy were conceived before that infamous Tuesday, and they were designed to combat different problems–for example, fire in the cargo hold.

"We don’t use the word ‘terrorist,’" says Ricky Frick, president and chief executive officer at Airworks Inc., referring to the promotion of his company’s new cabin surveillance system. "What we are ready to show to the airlines is not a prototype or concept; it’s a system that we have discussed long before Sept. 11 with an airline for another purpose; hence, installations could begin immediately."

Another problem that faced airlines long before Sept. 11 is air rage. Many airlines view air rage as a more universal problem than terrorism and one that no mechanical screening system will help prevent.

Comprehensive statistics on the problem are not available; not all airlines have kept accurate records of air rage incidents. However, according to a survey of 62 carriers conducted by the International Air Transport Association (IATA), the number of air rage incidents rose from 1,132 in 1994 to 5,416 in 1997, a 378 percent increase within just four years.

However, the problem of disruptive passengers hasn’t necessarily brought a boom to the cabin surveillance market. "We have products that have been approved for cabin security for some time," says Mike Neder, director of airline sales for DAC International. "But if you proposed surveillance systems to the airlines before Sept. 11, you’d starve to death."

Passenger Database

A system strongly supported by the British Airline Pilot’s Association was developed by UK-based QinetiQ. It is popular because it could help prevent possible terrorists or disruptive passengers from even entering the aircraft. The company’s MatchMaker system provides carriers with a database of disruptive passengers. Using standard ground communication technologies that sometimes incorporate encryption, subscribing airlines would be able to access the database, which includes information fed from the airlines, governments, police forces and other agencies. Visit

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