How often must a complete maintenance inspection be performed on a helicopter?

The requirement for a complete maintenance inspection on a helicopter is guided by the Aircraft Maintenance Manual (AMM) specific to that helicopter model and is governed by regulations that ensure the safety and airworthiness of the aircraft. Aircraft manufacturers outline the necessary maintenance cycles in the AMM, which can vary significantly depending on the design and purpose of the helicopter.

Choosing the option stating "as per the Aircraft Maintenance Manual and not exceeding 100 flight hours" accurately reflects the principle that maintenance schedules should adhere to manufacturer recommendations, ensuring that inspections are thorough and timely based on the operational nuances of the helicopter. This approach helps in addressing wear and tear, ensures compliance with regulatory standards, and maintains safety margins.

The other options either provide a fixed interval that may not be appropriate for all helicopter types or suggest a frequency that does not take manufacturer specifications into account. For example, a maintenance plan that mandates inspections every 50 or 200 flight hours may not align with specific helicopter requirements, leading to either premature inspections or insufficient maintenance, which can jeopardize airworthiness and safety. Likewise, a monthly requirement could be impractical for rotorcraft that operate on longer cyclical maintenance needs. Thus, aligning maintenance inspections with the guidance of the AMM ensures both regulatory compliance and operational safety.