Sensis concept targets runway incursions

 - September 26, 2007, 12:01 PM

Honeywell and Sensis demonstrated in August a concept of providing automated, individual voice warnings to pilots about to fall prey to a runway incursion accident. Unlike the current procedure, the concept technology issues the warning to the pilots at the same time as the air traffic controllers. At present, the controller becomes aware of a potential accident, identifies the aircraft involved and then warns the pilots, a process that consumes precious time.

The concept combines Sensis airport surface detection equipment, type X (ASDE-X) and its associated Safety Logic system with Honeywell’s aircraft mode-S transponder and TCAS units. Essentially, while the radar tracks all surface traffic, the Safety Logic component uses the fused data of the ASDE-X system (surface movement radar, multilateration, ADS-B) to precisely position all aircraft and vehicles and then continuously assess the multiple possibilities of incursion threats.

Should a threat appear, the system transmits a mode-S alert to the aircraft
involved, using their airplane-specific mode-S addresses. In turn, the mode-S transponders of the aircraft pass the alert to their TCAS units, which instantly issue an audio alert on the flight deck.

AIN participated in airport surface and in-flight demonstrations of the process at the Syracuse, N.Y. airport, where Honeywell operated its Sabreliner and King Air testbeds in two simulations. In the first, the Sabreliner and King Air began simultaneous takeoffs on Runway 10 and Runway 15, respectively. The two runways intersect at their far ends.

As the aircraft accelerated down their respective runways, the pilots of both aircraft heard clear and repeated “converging traffic” audio warnings, allowing ample room to stop before the intersection. In the second demonstration, the King Air was on short final to Runway 28 when the Sabreliner taxied forward onto the runway from the hold-clear point. This time, the King Air received a clear, repeated “runway occupied” audio alert and executed a missed approach.

Company officials emphasized that their respective equipment required only minimal modifications to perform the two simulations, which were intended to demonstrate the potential of the concept and did not represent any sort of production design.
“Incursion prevention involves multiple factors, and Honeywell and Sensis have taken the first step down this path,” said Tony Lo Brutto, v-p and general manager of Sensis Air Traffic Systems. “Much more work remains, but detection and alerting are of immediate value and are a great first step.”

ASDE-X and its Safety Logic component are currently being installed at 35 of the nation’s busiest airports, where potential conflicts are immediately highlighted on controller displays. A National Air Traffic Controller Association spokesman recently described ASDE-X as “very effective in helping controllers prevent runway incursions.”

Nevertheless, a controller’s warning over the sometimes busy ground frequencies still risks being missed or misinterpreted by pilots, with the attendant risk of the warning being “stepped on” by other transmissions. The Honeywell/Sensis demonstrations suggest that no pilot would be entirely satisfied until he had the ASDE-X alerts coming directly into the flight deck.   

ASDE-X-equipped Airports

Seattle-Tacoma International Airport

Lambert-St. Louis International Airport

Hartsfield-Jackson Atlanta International Airport

Bradley International Airport, Windsor Locks, Conn.

General Mitchell International Airport, Milwaukee

Orlando International Airport

Theodore Francis Green Airport, Providence, R.I.

William P. Hobby Airport, Houston

Charlotte Douglas International Airport,   Charlotte, N.C.

Louisville International Airport

Chicago O’Hare International Airport

Source: Sensis