Another Secondary Barrier

Air Safety Week, Oct 25, 2004

California-based U.S. Technical, an aerospace engineering company, is offering a cockpit "fortress" door that can easily be modified into a secondary barrier at less cost than the metal cable-type secondary barrier United Airlines is installing on its jets (see ASW, Sept. 27). United's secondary barrier costs around $25,000. Jerry Schumacher, vice president of U.S. Technical, said his company could offer a secondary barrier for less than $10,000.

The secondary barrier is an adjunct to the primary purpose of his company's design - which is to serve as a barrier to unwanted cockpit entry for those airplanes that are neither designed nor equipped with cockpit doors of any type. Examples of such aircraft include the Raytheon Beech 1900D, a popular twin turboprop in service with regional airlines, and the giant Boeing 747 freighter.

On the Beech 1900D, the door is a tri-fold assembly of bullet and kniferesistant material. It is pulled from the folded stowed position across the door and mechanically locked into place. When locked into place, it meets the 300-joule impact requirement, which equates roughly to a 210-lb. man running at full steam into the door. The door meets Federal Aviation Administration (FAA) requirements for the reinforced cockpit doors installed on the big jets in the aftermath of the 9/11 attacks.

Schumacher said a supplemental type certificate (STC) has been granted to install the barrier as a cockpit door, four have been installed and 42 others have been sold for installation in Beech 1900Ds. As in the case of the United secondary barrier installation, Schumacher said an STC would not be needed to install his company's design as a secondary barrier. Either as a door or as a barrier, the design could be made to fit any aircraft.

When installed to protect the cockpit, the door features a ballisticproof four-by-six inch window. The assembly also meets the require-ment to accommodate a rapid decompression of the airplane. The door also satisfies the re-quirement for emergency evacuation of the cockpit. "There is a push going on for secondary barriers, and we think we have an easy, simple fix," Schumacher said.

Another application applies to cargo jets. As in the case of the B747F, many of these aircraft do not feature cockpit doors, and there is no bulkhead in which to fit such a door. Schumacher said his company's tri-fold door could be fitted to such cargo aircraft, and the arrangement would include a bulkhead of the same material. On a "reasonable fleet size," he estimated that the complete installation would cost around $25,000. The installation would weigh on the order of 55 pounds, including bulkhead. >> Schumacher, e-mail jerryschumacher@ustechnical.com <<

[Copyright 2004 PBI Media, LLC. All rights reserved.]