For Video Lecture of this presentation: https://youtu.be/XNsIdHUx7q8 The topics covered in this session are, Airplane (fixed wing aircraft) configurations and various parts of airplane. A detailed list of airplane configuration is discussed with general insight about airplane parts. Attention! "Gate Aerospace Engineering aspirants", A virtual guide for gate aerospace engineering is provided in "Age of Aerospace" blog for helping you meticulously prepare for gate examination. Respective notes of individual subjects are provided as 'Embedded Google Docs' which are frequently updated. This comprehensive guide is intended to efficiently serve as an extensive collection of online resources for "GATE Aerospace Engineering" which can be accessed free of cost. Use the following link to access the study material https://ageofaerospace.blogspot.com/p/gate-aerospace.html

1. GATE AEROSPACE ENGINEERING
Topic wise solved questions
FLIGHT MECHANICS - BASICS
Question Analysis | Important Concepts | Formulae | Solutions | Book Reference
1

2. Topic of discussion
Basics: Atmosphere: Properties, standard atmosphere. Classification of
aircraft. Airplane (fixed wing aircraft) configuration and various parts.
Year 1 Mark 2 Mark Year 1 Mark 2 Mark
2007 - - 2014 - -
2008 - 3 2015 2 -
2009 - - 2016 1 -
2010 - - 2017 - -
2011 1 - 2018 1 1
2012 - - 2019 - -
2013 - - 2020 - -
Allocation 1 Mark 2 Mark Overall
Total 5 4 9
2Question Analysis | Important Concepts| Formulae | Solutions | Book Reference
FLIGHT MECHANICS

3. 3
SYLLABUS
Question Analysis | Important Concepts | Formulae | Solutions | Book Reference
FLIGHT MECHANICS

4. 1. 5 types of Altitudes (Geometric, Absolute, Geopotential, Pressure & Density)
2. 5 Layers of Atmosphere (Troposphere [0-12 km], Stratosphere [12-50km], Mesosphere [50-80 km], Thermosphere
[80-700km], Exosphere [700 km-Beyond])
3. ISA Chart (Lapse Rate*)
4. Properties of atmosphere : Pressure, Temperature,
Density.
Lapse Rate For different Layers a = (dT/dh) Units:K-Kelvin; m-metre
(0 km - 11 km) a1 = -6.5 x 10
-3
K/m (53 km - 79 km) a3 = -4.5 x 10
-3
K/m
(25 km - 47 km) a2 = 3 x 10
-3
K/m (90 km -105 km) a4 = 4 x 10
-3
K/m
4Question Analysis | Important Concepts | Formulae | Solutions | Book Reference
FLIGHT MECHANICS
ByCmglee-Ownwork,CC
BY-SA3.0

5. 5Question Analysis | Important Concepts | Formulae | Solutions | Book Reference
FLIGHT MECHANICS
Classification of aircraft
Image Source: Irish Aviation Authority
Airplane (fixed wing aircraft) parts
Image Credits: Inspirational Technologies

6. 6Question Analysis | Important Concepts | Formulae | Solutions | Book Reference
FLIGHT MECHANICS

7. 7Question Analysis | Important Concepts | Formulae | Solutions | Book Reference
FLIGHT MECHANICS
GATE 2008 Atmosphere: Properties, standard atmosphere 2 Mark
Q1. Which of the following statements is TRUE as the altitude increase in stratosphere of International
Standard Atmosphere?
(A) Temperature increases and dynamic viscosity decreases
(B) Temperature remains constant and pressure increase
(C) Temperature decrease and sound speed decreases.
(D) Temperature remains constant and density decreases
Explanation:
In general temperature is considered to be constant or increase in the
stratosphere (12-50km), the dynamic viscosity (Gases) and speed of
sound are increase with temperature. We also know that pressure and
density decreases with increase in altitude.
Answer:
(D) Temperature remains constant and density decreases
Note: Dynamic viscosity decreases with temperature for liquids
ByCmglee-Ownwork,CCBY-SA3.0

8. 8Question Analysis | Important Concepts | Formulae | Solutions | Book Reference
FLIGHT MECHANICS
GATE 2016 Atmosphere: Properties, standard atmosphere 1 Mark
Q2. During an aircraft cruising flight, the altitude above the ground is usually measured using
(A) dynamic pressure (B) static pressure
(C) radar (D) Laser range finder
Explanation:
• Dynamic pressure (Q = 0.5𝜌v2) is generally used for defining lift and drag.
• The static pressure system (Static port) is open to the exterior of the aircraft to
sense the pressure of the atmosphere at the altitude at which the aircraft is
flying.
• A radar altimeter, measures altitude above the terrain presently beneath an
aircraft by timing how long it takes a beam of radio waves to travel to ground,
reflect, and return to the craft. Radar altimeters generally only give readings up
to 2,500 feet (760 m) above ground level (AGL). frequently used by commercial
aircraft for approach and landing, especially in low-visibility conditions
• A laser rangefinder uses a laser beam to determine the distance to an object.
Answer:
(B) static pressure
Image Credits: Wikimedia commons

9. 9Question Analysis | Important Concepts | Formulae | Solutions | Book Reference
FLIGHT MECHANICS
GATE 2015 Atmosphere: Properties, standard atmosphere 1 Mark
Q3. Consider the density and altitude at the base of an isothermal layer in the standard atmosphere to be 𝜌1
and ℎ1, respectively. The density variation with altitude (𝜌 versus h) in that layer is governed by (𝑅: specific
gas constant, 𝑇: temperature, 𝑔𝑜: acceleration due to gravity at sea level)
(A) (B)
(C) (D)
Answer:
(A)
Formula:

10. 10Question Analysis | Important Concepts | Formulae | Solutions | Book Reference
FLIGHT MECHANICS
GATE 2015 Atmosphere: Properties, standard atmosphere 2 Mark
Q4. Assuming ISA standard sea level conditions (288.16 K, density of 1.225 kg/m3, g = 9.81 m/s2, R = 287
J/(kg-K)), the density (in kg/m3) of air at Leh, which is at an altitude of 3500 m above mean sea level is
________ (accurate to two decimal places)
Answer: 0.85 to 0.88
Solution:

11. 11Question Analysis | Important Concepts | Formulae | Solutions | Book Reference
FLIGHT MECHANICS
GATE 2015 Airplane (fixed wing aircraft) configuration 1 Mark
Q5. Consider a monoplane wing and a biplane wing with identical airfoil sections, wingspans and incidence
angles in identical conditions in a wind tunnel. As compared to the monoplane, the biplane experiences
(A) a higher lift and a higher drag (B) a higher lift and a lower drag
(C) a lower lift and a lower drag (D) a lower lift and a higher drag
Explanation:
A monoplane has one wing, a biplane has two wings. With the wing parameters
being same a biplane will experiences approximately twice the lift and drag
(neglecting up-wash, downwash etc.) as the number of wings is doubled
Answer:
(A) a higher lift and a higher drag
Image Credits: aviation.stackexchange.com

12. 12Question Analysis | Important Concepts | Formulae | Solutions | Book Reference
FLIGHT MECHANICS
GATE 2008 Airplane (fixed wing aircraft) parts 2 Mark
Q6. The primary function of fin in vertical tail of an aircraft is to provide
(A) Yaw Control (B) Yaw Stability
(C) Roll Damping (D) Roll Stability
Explanation:
A vertical stabilizer provides directional (or yaw) stability and usually comprises a fixed fin and movable control
rudder hinged to its rear edge. Less commonly, there is no hinge and the whole fin surface is pivoted for both stability
and control.
Answer:
(B) Yaw Stability
Image Credits: Researchgate

13. 13Question Analysis | Important Concepts | Formulae | Solutions | Book Reference
FLIGHT MECHANICS
GATE 2011 Airplane (fixed wing aircraft) parts 1 Mark
Q7. Which one of the following high lift devices results in higher stalling angle
(A) Split Flap (B) Fowler Flap
(C) Plain Flap (D) Leading Edge Flap
Explanation:
Based on the CL Vs Alpha plot, The split flap has a greater stall angle.
Answer:
(B) Split Flap
Image Credits: aviation.stackexchange.com; Aviationchief.com

14. 14Question Analysis | Important Concepts | Formulae | Solutions | Book Reference
FLIGHT MECHANICS
GATE 2011 Airplane (fixed wing aircraft) parts 1 Mark
Q8. Winglets are used on wings to reduce
(A) Skin friction drag (B) Profile drag
(C) Wave drag (D) Induced drag
Explanation:
• Skin friction drag can be reduced by smoothening the surface
• Profile drag can be reduced by aerodynamically designing a surface
• Wave drag (shock) can be reduced by wing sweep etc.
• The wingtip devices increase the lift generated at the wingtip, and
reduce the lift-induced drag caused by wingtip vortices
Answer:
(d) Induced Drag
Image Credits: aerospaceengineering.net

15. 15Question Analysis | Important Concepts | Formulae | Solutions | Book Reference
FLIGHT MECHANICS
GATE 2018 Airplane (fixed wing aircraft) parts 1 Mark
Q9. The pilot of a conventional airplane that is flying steady and level at some altitude, deflects the port side aileron up
and the starboard aileron down. The aircraft will then
(A) pitch, nose up (B) roll with the starboard wing up
(C) pitch, nose down (D) roll with the port wing up
Explanation:
As the port side (Left) aileron up and the starboard (right) aileron down. The
aircraft will then roll in anticlockwise direction.
Answer:
(B) roll with the starboard wing up
Image Credits: www.motionrc.com
Image Credits: Quora

16. 16Question Analysis | Important Concepts | Formulae | Solutions | Book Reference
FLIGHT MECHANICS
1. Atmosphere: Properties, standard atmosphere
• Introduction to Flight (7th Edition) - John D. Anderson - Pg.No: (110-133/945)
• Aircraft Performance & Design - John D. Anderson - Pg.No: (545-565)
2. Airplane (fixed wing aircraft) configuration and Parts
• Airplane Design: Preliminary configuration design and integration
of the propulsion system - Chapter 3: Selection of the overall
Configuration - Pg.No: (25-106).

17. 17