Here are the top 50 commonly asked questions in Aircraft Design interviews. Whether you’re just starting your preparation or need a quick refresher, these questions and answers will help you tackle your interview with confidence.
Basic Aircraft Design Interview Questions with Answers
1. What is an Aircraft?
An aircraft is a machine that is able to fly in the air. It produces lift using wings and may have its own on-board propulsion. Common examples are airplanes, helicopters etc.
2. How do Aircrafts produce lift?
Aircrafts produce lift mainly using wings. They are made in a special shape called airfoils. Airfoils produce lift when they reach a certain speed and at a certain angle.
3. How did Aircrafts start in the beginning?
Aircrafts took inspiration from hot air balloons for their flight characteristics. There were some other attempts like kites and rotor wings as well. However in the end, fixed wing aircrafts became popular.
4. What are lighter-than-air Aircrafts?
Lighter-than-air aircrafts are those, which are lighter than air itself. This means that they can take advantage of the wind for flight and easily produce the required lift.
5. What were airships in Aircraft Design?
Airships were basically balloons that could be steered. They moved very slowly but were stable in the air. It was during the 20th century that their design got better and people started to use them to travel.
6. What are some early examples of heavier-than-air Aircrafts?
Parachutes were designed and developed early in the 16th century but were never practically used. Kites were also developed during 19th century. However, both these early attempts never caught public attention.
7. Who were the pioneers of Aircrafts capable of sustained flight?
It was Leonardo da Vinci who first recognized that human power was not enough for sustained flight. Then Robert Hooke also came to that conclusion during the 17th century. Then Sir George Cayley developed the physics of flight.
8. Who developed the first modern Aircraft?
Sir George Cayley was the person who developed the world’s first modern aircraft. He had devoted his life into studying and understanding the physics of flight. He was the first to design the modern heavier-than-air aircraft.
9. What were George Cayley’s contributions to modern Aircrafts?
His contributions were to lay down the principles of heavier-than-air flight along with scientific understanding of bird flight. He also conducted scientific experiments to understand the phenomena of drag and airfoils.
10. What was the first steam-powered Aircraft?
The first steam-powered aircraft was made by William Samuel Henson. He made it during mid-19th century drawing inspiration directly from George Cayley’s flight principles. It was also the first propeller driven fixed wing aircraft.
11. Which was the Wright brothers’ first Aircraft?
Their first aircraft that flew was called Flyer. That aircraft solved the problems that previous aeronautical pioneers were facing. They included a rudder on the rear of the aircraft for more control, which is standard practice today.
12. Where was the first sustained flight by an Aircraft recorded?
The first sustained flight attempt was made by the Wright brothers on 17 December, 1903. They flew their aircraft Flyer and by the end of the day were able to fly a distance of 260 m in 59 seconds.
13. What was the first practical Aircraft that flew consistently?
The first practical aircraft that flew consistently was the Flyer III. It was an improvement on the design of the earlier Flyer aircraft made by the Wright brothers. On October 5 1905, it was flown by Wilbur Wright for 39 km.
14. What was the pioneer era of aviation and Aircrafts?
This era came in the period leading up to the first world war. Power issues and controllability of the aircrafts were sorted during this period. However, some progress was still needed to create a machine for general use.
15. What were earlier design to increase lift in Aircrafts?
Biplanes were designed to increase the lift of aircrafts however they weren’t very strong structurally. Triplanes too were experimented with but to no avail. Successful concepts like fairings were introduced and enclosed cockpits.
16. What were the Zeppelin Aircrafts?
Zeppelin aircrafts were a type of an airship that was mainly used by Germany during World War I. The airships themselves were later on used throughout the world until modern aircrafts were developed.
17. Why were Zeppelin Aircrafts used?
Zeppelin aircrafts were used by the German military for reconnaissance purposes. They were used in the North Sea and Baltic regions. Along with this they were used for bombing raids over England and the Eastern Front.
18. What is the jet age of Aircrafts?
The jet age is the period in history that came after the second world war. This period is defined by the advent of jet, or turbine, engines used to propel aircrafts.
19. When was the first civil Aircraft flown?
The first civil aircraft to fly passengers was in 1952. The service was provided by a British company called de Havilland Comet. Later on, they also provided tans-Atlantic flights starting form 1958.
20. What is a rotary-wing Aircraft?
A rotary-wing aircraft, also known as a rotorcraft, is a type of heavier-than-air aircraft. It generates lift by rotating wings or blades. Common examples of this include helicopters and drones which have found popularity in today’s world.
Intermediate Aircraft Design Interview Questions with Answers
21. What are main activities in aircraft design?
The design of an aircraft has two main activities: problem solving related to mathematical formulas and making decisions about choosing configurations depending on scenario. Both of these are done by aircraft designers.
22. What is taper ratio of a wing?
The taper ratio is the ratio we get by dividing the root chord by the tip chord of the wing. The ranges for taper ratio include being zero, between zero and one, and equal to one.
23. What is elliptical wing lift distribution?
It is supposed to be the best type of lift distribution. The lift generated per unit span has an even distribution and has the highest Oswald efficiency factor.
24. What is the sweep angle of a wing?
When looking at a wing from the top, the angle that the chord line makes with the centerline of the fuselage is called the sweep angle. It is done to delay wave drag produced at transonic speeds.
25. What is a dihedral angle?
An aircraft when viewed from the front, will have wings that are perpendicular to the fuselage. If the wings are tilted upwards from the tip, then they are said to have a dihedral angle.
26. What is an anhedral angle given to wings?
Anhedral angles are the opposite of dihedral angles. When the wings appear to be tilted down then they are called anhedral angles. It is done on transport aircraft to improve their maneuvering power.
27. What are canard tails?
Canard tails are the horizontal tails placed before the wings in an aircraft. They were used mostly in some supersonic aircrafts and also in some fighter jets although they are rarely used now-a-days.
28. What is a horizontal stabilizer?
A horizontal stabilizer is an important part of any tail and house of the elevator along with it. The main function of it is to keep the aircraft statically stable by producing a moment to counter that produced by the wings.
29. What is optimum tail arm?
The tail arm of an aircraft is said to be the distance between the MAC of the horizontal stabilizer and the wing. The optimum tail arm is the optimum distance between the two, so that the drag effect is minimized.
30. What is a fuselage?
The fuselage is the structure in which the pilot, crew and passengers sit. It is also the place where all the payload is stored. The fuselage is the main connecting point for the aircraft’s appendages like the wings and the tail.
31. Where is fuel stored in aircraft?
The fuel is stored in fuel tanks that are designed to be kept closer to the aircraft’s center of gravity. They may be placed inside the wings or in storage compartments inside the fuselage.
32. What is a flight phase?
A flight phase is the part of a flight where some specific task, which is the main priority, has to be conducted. This can include taking-off or landing, cruising etc. Military missions usually have their own flight phases.
33. What is an airfoil?
An airfoil is a special shape with which, when converted into a 3D structure, lift is produced. Airfoils generally produce lift at lower speeds and at lower angle of attack. They also give minimal drag.
34. What are landing gears?
Landing gears on an aircraft help it to land on the ground using wheels. This increases the comfort while landing and also allows the aircraft to come to a halt gradually rather stopping immediately.
35. What is a tricycle landing gear?
Tricycle landing gears are mainly used in small aircrafts. They have one nose gear and two main landing gears. Tricycle landing gears are more stable on the ground as well as during taxi.
36. What are symmetrical airfoils?
Symmetrical airfoils are called so because of their symmetrical shape. They produce zero lift at zero angle of attack. That is why they are usually placed at some angle of incidence to be effective.
37. What are cambered airfoils?
Cambered airfoils are unsymmetrical airfoils with more camber at the top edge. These airfoils produce more lift and also produce lift at zero angle of attack.
38. What is the chord length of an airfoil?
The chord length is the minimum distance between the leading edge and trailing edge of an airfoil. For symmetrical airfoils, the chord length is equal to its camber line but for cambered airfoils it is different.
39. What is the aspect ratio of a wing?
The aspect ratio is a property of the wing, which is defined by the mathematical relation of wingspan squared over the wing area. Aspect ratio can define what properties a wing have depending on which range it falls in.
40. What is a tail-dragger landing gear?
A tail-dragger landing gear has two main landing gears near the front of the aircraft and a small one beneath the tail. It increases the angle of attack of the aircraft directly on the runway so the elevator doesn’t have to make a big deflection.
41. What are the steps to design a wing?
The wing may be designed by selecting the number of wings first. Then the airfoil must be selected. The wing dimensions need to be finalized like the aspect ratio, taper ratio etc. If the objectives are met then move forward otherwise iterate more.
42. What is static stability of an aircraft?
Static stability is provided by the horizontal stabilizer of an aircraft. It is the tendency of the aircraft to revert back to its cruising condition when an external force is applied.
43. What is the vertical tail?
The vertical tail usually sits above the horizontal tail in an aircraft. It provides longitudinal control to the aircraft with the help of a rudder. Vertical tails are generally tapered in shape.
44. What are bicycle landing gears?
Bicycle landing gears are the ones which only have two main gears. This is a very minimalistic design for landing gears and is rarely used. However, it also contributes the least weight and drag amongst all the other types.
45. What is a high wing aircraft?
When the wings are placed higher vertically than the center of gravity of the fuselage, it is known as a high wing aircraft. This configuration provides more stability to the aircraft and also gives more lift.
46. What is a low wing aircraft?
Low wing aircrafts are those where the wings are placed below the CG of the fuselage. This configuration has more ground effect and therefore requires a shorter runway to take-off.
47. What is a mid-wing aircraft?
Mid-wing aircrafts are the best of both worlds in comparison to its counterparts. The wings are placed near about the vertical CG of the fuselage. It has the least amount of interference drag.
48. What is a V-tail?
A V-tail is basically a tail in a “V” shape. The two “V” shaped tails provide both horizontal and vertical stability. They both produce deflections to function as elevators as well as the rudder.
49. What is a rectangular wing?
A rectangular wing has its taper ratio equal to one. It is the simplest planform available to designers. The shape of the wing, when viewed from the top, will look like a rectangle.
50. What is a semi-tapered planform?
A semi-tapered planform has a rectangular section at the wing roots upto a certain point. After that the wing becomes tapered. This type of planform gives the advantages of both the types of planforms including good lift and less drag.
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