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GATE 2021 AE – Question 40

Flight Mechanics & Space Dynamics · Airplane performance: drag polar, take-off and landing, climb and descent, ceilings, range and endurance, load factor, turning flight, V-n diagram, winds · 2 marks · Multiple choice

At the top of an inverted vertical loop, the airplane load factor n satisfies

  1. n=1
  2. n<1
  3. n=-1
  4. n>-1

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Correct answer: (D) n>-1

Explanation

The accepted inequality is $n>-1$ (D). With signed lift referenced to the aircraft orientation for the inverted loop, the centripetal balance gives $n=V^2/(gR)-1$. Since $V^2/(gR)>0$, $n>-1$. Reusing the ordinary-loop sign convention gives a different inequality.

Official GATE 2021 answer key: https://gate2026.iitg.ac.in/doc/download/Answer_keys2021/ae_2021.pdf