Which two components are conventionally labeled No. 1 for the left side and No. 2 for the right side?

• A. Powertrain and Electronics
• B. Airframe and Avionics
• C. Left-hand components
• D. Flight controls

Answer: (B)

Grouping components by left- and right-hand sides follows a practical maintenance convention: the left side covers the airframe—the structural and mechanical elements that form the helicopter’s backbone—while the right side houses the avionics—the electrical and electronic systems that manage sensors, navigation, and flight information. This separation gives technicians a predictable layout, making it quicker to locate parts, follow inspection steps, and reference manuals. It also keeps wiring and electronics organized away from the airframe, aiding fault isolation and reducing interference. Other pairings mix domains that are kept distinct in this standard, whereas airframe on the left and avionics on the right aligns with how the aircraft is typically organized for servicing.