TAWS – Terrain Avoidance Warning Systems

 

THE FAA'S FINAL WORD ON THE SUBJECT.

 

                           On March 23, a year and a half after the first proposal was written, the Federal Aviation

                           Administration (FAA) issued its final report on the requirement for terrain awareness and

                           warning systems (TAWS). In short, the ruling, which becomes effective March 29, 2001,

                           stipulates that TAWS is mandatory for all U.S. registered turbine-powered aircraft with six or

                           more passenger seats.

 

                           The final rule addresses two classes of TAWS equipment: Class B systems, which

                           represent functions available in current ground proximity warning systems (GPWS), and

                           Class A systems, which include basic GPWS functions plus more features and a visual

                           display. Class A applies to all Part 121 operations and Part 135 operations with aircraft

                           configured with 10 or more passenger seats. Part 91 aircraft with six or more passenger

                           seats and Part 135 aircraft with six to nine passenger seats fall into the less expensive

                           Class B category.

 

                           Aircraft manufactured on or before March 29, 2002 must be compliant before March 29,

                           2005. For manufacturers, turbine-powered aircraft rolling off the assembly line after March

                           29, 2002 must meet TAWS requirements.

 

                           The FAA did not propose changes to existing training requirements as part of the ruling.

                           However, the final notice states that the Airplane Flight Manual must contain appropriate

                           procedures for (1) the use of the terrain awareness and warning system; and (2) proper flight

                           crew reaction in response to the TAWS audio and visual warnings. The final rule is not

                           applicable to parachute, aerial application, and fire fighting operations.

 

                           WHY TAWS?

 

                           The report, which references FAA and National Transportation Safety Board (NTSB)

                           studies, shows that the FAA firmly believes TAWS will improve safety. "The Volpe

                           Part 91 study was conducted to consider installation of current GPWS or EGPWS

                           on all Part 91 turbine-powered airplanes of 6 or more passenger seats. The study concluded

                           that GPWS could have avoided 33 of the 44 (75 percent) [Controlled Flight Into Terrain]

                           accidents and 96 fatalities, and Enhanced GPWS could have avoided 42 of the 44 (95

                           percent) accidents and 126 fatalities.

 

                           These conclusions justify use of TAWS on all airplanes of six or more passenger seats.

 

                           Some industry leaders are skeptical and believe that the cost of TAWS is too burdensome

                           for most operators. But, regardless of the cost, operators have five years to make their

                           aircraft compliant. After which, hopefully, the FAA will be right and accidents will be

                           significantly reduced.

 

                           For a copy of the TAWS final ruling, call 202.267.9680 and mention docket number 29312

                           or click here for a link to the report in Microsoft Word format.