David Learmount reports that the Association of European Airlines is opposed to the US Federal Aviation Administration's proposal for continuous uninterruptible transponder operations (Flight International, 4-10 March).
The technology is available to prevent disabling of aircraft transponder (or other) circuits without compromising electrical system protection or relocating transponder circuits. Texas Instruments has designed a tamper-proof variant of its standard circuit breaker with a modified pushbutton that essentially prohibits unauthorised manual opening of the circuit breaker, thereby preventing the actions that have been presumed to have occurred in the 11 September attacks. Your report also highlighted the concerns of flightcrews relative to a continuous, uninterruptible transponder and the inability to deactivate the system in the event of a false alarm.
To address this, Texas Instruments has developed a design enhancement that would allow pilots a means to readily open the circuit breaker in the event of an anomalous condition. Specific details cannot be revealed for obvious reasons.
Robert Correa Texas Instruments, Attleboro, Massachusetts, USA
Source: Flight International
