A Part 121 certificate holder is configuring a new airplane type for passenger service with 45 passenger seats. Under 14 CFR 121.318, what type of public address (PA) system is required for this aircraft?
- AA PA system audible to all passengers and crew, irrespective of seat count.
- BNo PA system is required for aircraft with fewer than 50 passenger seats.
- CA PA system that meets the standards of 121.318(a) and is capable of operation independent of the interphone system.
- DA PA system that automatically broadcasts pre-recorded safety announcements.
Show answer & explanationAnswer & explanation
Correct answer: C. A PA system that meets the standards of 121.318(a) and is capable of operation independent of the interphone system.
14 CFR 121.318(a) states that no person may operate a large airplane configured for passenger operations, other than an all-cargo operation, unless it is equipped with a public address system that meets the standards of 121.318(a) and is capable of operation independent of the interphone system. This requirement applies regardless of the number of seats, as long as it's a 'large airplane' in passenger operations. A 45-seat aircraft typically falls under 'large airplane' for Part 121.
Why the other options are wrong
- A. While audibility is a characteristic, the specific regulatory requirement includes independence from the interphone system.
- B. This is incorrect; the requirement applies to all large airplanes configured for passenger operations, regardless of specific seat count (above a certain threshold for 'large').
- D. Automatic pre-recorded announcements are a common feature but not a specific regulatory requirement for the *type* of PA system under 121.318.
PA System Requirement (121.318)
Mandates the installation of a public address system on Part 121 large passenger-carrying aircraft to facilitate communication with passengers and crew, especially during emergencies.
- Required on all large passenger-carrying airplanes.
- Must be operable independent of the interphone system.
- Ensures clear communication for safety announcements.
Memory trick: PA System: 'P' for Public, 'A' for Announcements, 'S' for Separate from Interphone.