Discussion
At high subsonic Mach numbers a large transport can develop an aperiodic longitudinal divergence known as the tuck mode. Its dynamic signature is
Answer: A
Tuck appears when the pitching moment derivative with speed turns negative as the aerodynamic centre moves aft with Mach number. That drives \( E \) through zero and negative, producing a real positive root and a nose-down divergence with no oscillation, which is why a Mach trim system is fitted to sense the condition and apply compensating trim. Short-period frequency is set by stiffness in incidence and is not what changes here. The phugoid period is tied to trim speed and does not collapse. Purely imaginary roots would be the boundary of an oscillatory instability, a different case entirely.
Post your comment
Please log in or register to post a comment.
Examination Categories
- SSC Exams
- Banking Exams
- Teaching Exams
- Civil Services Exams
- Railways Exams
- Engineering Recruitment Exams
- Defence Exams
- State Government Exams
- Police Exams
- Insurance Exams
- Nursing Exams
- Other Government Exams
- NRA CET
- PG Entrance Exams
- Campus Placement
- MBA Entrance Exams
- CUET and UG Entrance
- Judiciary Exams
- Regulatory Body Exams
- Software Development