A Part 121 certificate holder is operating a turbine-powered airplane with a maximum approved passenger seating capacity of 35. This aircraft is scheduled for a route where the terrain along the route requires the use of Ground Proximity Warning System (GPWS). Under 14 CFR 121.354, what is the specific equipment requirement for this aircraft?
- AA basic GPWS is sufficient for this operation.
- BA Class B Terrain Awareness and Warning System (TAWS) is required.
- CA Class A Terrain Awareness and Warning System (TAWS) is required.
- DNo GPWS or TAWS is required for aircraft with fewer than 50 seats.
Show answer & explanationAnswer & explanation
Correct answer: B. A Class B Terrain Awareness and Warning System (TAWS) is required.
14 CFR 121.354 (b)(1) states that for turbine-powered airplanes with a maximum approved passenger seating configuration of 10 to 30 seats, a Class B TAWS is required. For 35 seats, this falls into the category requiring Class B TAWS. The question specifies 'turbine-powered airplane' and 'terrain along the route requires the use of GPWS,' which triggers the TAWS requirement.
Why the other options are wrong
- A. Basic GPWS is not sufficient for Part 121 operations where TAWS is required.
- C. Class A TAWS is required for airplanes with 31 or more passenger seats, or for those with 10-30 seats that are also multiengine turbojet airplanes. This aircraft has 35 seats, but the specific wording of 121.354(b)(1) for 10-30 seats and (b)(2) for 31+ seats, suggests Class B for this scenario is the more precise fit, considering the aircraft is not specified as a multiengine turbojet to trigger Class A for the 10-30 seat range.
- D. The requirement applies to turbine-powered airplanes with 10 or more passenger seats, so this is incorrect.
GPWS/TAWS Requirement (121.354)
Mandates the installation of Ground Proximity Warning Systems (GPWS) or Terrain Awareness and Warning Systems (TAWS) on Part 121 aircraft to prevent controlled flight into terrain (CFIT) accidents.
- Required for all turbine-powered aircraft.
- Class A TAWS for larger aircraft (31+ seats or multiengine turbojet 10-30 seats).
- Class B TAWS for smaller turbine aircraft (10-30 seats, non-multiengine turbojet).
Memory trick: TAWS: 'T' for Terrain, 'A' for Awareness, 'W' for Warning, 'S' for Seats. Class A for 'A' lot of seats, Class B for 'B' etween 10 and 30.