Where are lavatory smoke detectors typically installed on an aircraft?

Lavatory smoke detectors are typically installed in the lavatory ceiling or within the air ducts of an aircraft. This strategic placement is critical for detecting any smoke or signs of fire as early as possible. The ceiling location allows the detectors to sense smoke that rises quickly, while the air ducts can facilitate the detection of smoke being drawn in or circulating within the aircraft’s ventilation system.

By positioning smoke detectors in these areas, aircraft safety measures are significantly enhanced, as they can trigger alarms and alert the crew to potential fire hazards, thereby allowing for prompt action to be taken. This proactive safety feature aligns with aviation regulations and best practices aimed at ensuring passenger and crew safety at all times.

The other options are less suitable because they do not adequately cover the crucial areas where smoke may originate in lavatories, which are often used and may pose a risk for fire hazards due to equipment like cigarette receptacles, or the use of flammable products.