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GATE 2019 AE – Question 50

Flight Mechanics & Space Dynamics · Rigid body dynamics: linear and angular momentum balance · 2 marks · Numerical answer

An airplane starts a symmetric pull-up from steady level flight with nose-up pitch acceleration 20 deg/s². At this instant its CG vertical load factor is 2. Point P on its nose is 2 m ahead of CG. With g=9.81 m/s², find the vertical load factor at P (two decimal places).

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Correct answer: 2.06 to 2.08

Explanation

At initiation the pitch rate is zero, so the extra vertical acceleration at P is the tangential term $\dot q\,l=(20\pi/180)2=0.6981$ m/s². Divide by g and add to the CG load factor: $n_P=2+0.6981/9.81=2.0712$, or 2.07.