Which of the following components is NOT inapplicable to an airplane (i.e., all are applicable aeronautical components)?

Introduction / Context:
Basic airplane architecture includes lifting surfaces, propulsion, control surfaces, and fuselage. Recognizing the standard nomenclature helps avoid confusion when interpreting airport and aircraft design problems.

Given Data / Assumptions:

• Conventional fixed-wing aircraft (propeller or jet).
• Common terminology: wings, engines, fuselage, and air screw (propeller) for prop-driven aircraft.

Concept / Approach:
All listed items are legitimate aircraft components. While jet airplanes do not have an air screw, the term is still applicable to propeller-driven airplanes; thus, as a general statement about “aeroplanes,” none of the listed items is inapplicable.

Step-by-Step Solution:
Wings: primary lifting surfaces present in virtually all fixed-wing airplanes.Engines: provide thrust (propellers or jets); all powered aircraft have engines.Air screw: propeller component applicable to propeller-driven types.Fuselage: central body housing crew, payload, and systems.

Verification / Alternative check:
Aircraft systems texts clearly define these components across multiple configurations, confirming applicability.

Why Other Options Are Wrong:

• Picking any specific component as “not applicable” would be incorrect because each appears in common aircraft types.

Common Pitfalls:

• Assuming “air screw” is obsolete and therefore inapplicable; it remains valid for prop aircraft.
• Confusing helicopter rotors with airplane propellers; both are airscrews but used differently.

Final Answer:
None of these