Lecture 15

Question 1

What is the fundamental principle behind a turbojet engine?

Answer 1

Air is compressed by intake shape and fan blades, then ignited to produce thrust.

Question 2

What component in a turbojet endures extreme temperature changes?

Answer 2

The turbine blades at the back of the engine.

Question 3

What is a turbofan engine?

Answer 3

A jet engine with a fan that bypasses some air around the core, improving fuel efficiency.

Question 4

What engine type was used by the Germans during WWII for fast aircraft?

Answer 4

The pulsejet engine.

Question 5

What is unique about a pulsejet engine’s operation?

Answer 5

It has no shaft or turbines and only works once the aircraft is already moving at high speed.

Question 6

What was the starting speed required for a pulsejet engine to ignite?

Answer 6

300 km/h.

Question 7

What speed could a German pulsejet engine reach at maximum?

Answer 7

600 km/h.

Question 8

What is a ramjet engine?

Answer 8

A hollow pipe design where air is compressed by speed and mixed with fuel to generate thrust.

Question 9

What is the theoretical top speed capability of a ramjet?

Answer 9

Ten times the speed of sound.

Question 10

Why are ramjets rarely used in aircraft?

Answer 10

They require extremely high start speeds and consume huge amounts of fuel.

Question 11

Who is credited with the first jet-powered aircraft?

Answer 11

Henri Coandă from Romania.

Question 12

What type of engine did Henri Coandă build?

Answer 12

A motorjet powered by an internal combustion engine.

Question 13

What happened during Coandă’s 1910 test flight in France?

Answer 13

The plane caught fire and burned down; he never flew again.

Question 14

Who is commonly credited in the West with inventing the jet engine?

Answer 14

Frank Whittle from Britain.

Question 15

What flaw did Frank Whittle’s 1937 engine design have?

Answer 15

Restricted air access and external burners made airflow insufficient.

Question 16

Who developed the modern turbojet engine used today?

Answer 16

Hans von Ohain, a German physicist.

Question 17

What was the first operational jet aircraft built using von Ohain’s design?

Answer 17

The Heinkel He 178.

Question 18

What was the performance capability of the Heinkel He 178?

Answer 18

It reached speeds up to 650 km/h.

Question 19

What German fighter jet first used turbojet engines in combat?

Answer 19

The Messerschmitt Me 262.

Question 20

What was the Me 262’s top speed advantage in combat?

Answer 20

It was about 100 km/h faster than any Allied aircraft.

Question 21

Why couldn’t the Me 262 change the course of WWII?

Answer 21

It wasn’t produced in large enough numbers due to resource limitations and political interference.

Question 22

What did Hitler believe the Me 262 should be used for?

Answer 22

As a bomber, not a fighter.

Question 23

Who reported Hitler’s opposition to the Me 262?

Answer 23

Albert Speer.

Question 24

What was a technical issue with the Me 262’s engines?

Answer 24

Poor metallurgy led to blade failures and flameouts during sudden throttle changes.

Question 25

What rocket-powered aircraft broke speed records in WWII?

Answer 25

The Messerschmitt Me 163.

Question 26

What speed did the Me 163 reach?

Answer 26

Over 1000 km/h, approaching the sound barrier.

Question 27

What made the Me 163 dangerous to fly?

Answer 27

Its unstable rocket fuels (T-Stoff and C-Stoff) could ignite or explode from vibrations.

Question 28

Where were the fuel tanks placed in the Me 163?

Answer 28

One under the pilot and one behind, increasing the risk of fatal explosions.

Question 29

Who was a famous test pilot for the Me 163?

Answer 29

Hanna Reitsch.

Question 30

Why did many pilots die in high-speed test flights?

Answer 30

Control systems failed at high speeds, and structural disintegration occurred near Mach 0.9.

Question 31

What happens to airplanes approaching transonic speeds?

Answer 31

They experience a mix of supersonic and subsonic airflows, leading to shock waves and instability.

Question 32

What are transonic speeds?

Answer 32

Speeds approaching the sound barrier where airflow transitions cause severe turbulence.

Question 33

What structural effects did transonic speeds have on early aircraft?

Answer 33

Planes often vibrated violently or broke apart midair.

Question 34

Why did engineers revisit WWII aircraft designs post-war?

Answer 34

To solve shock wave and stability issues at transonic speeds.

Question 35

Which ancient civilization is believed to have created the first jet-like engine?

Answer 35

The Ancient Alexandrians.

Question 36

What was the Alexandrian invention considered an early jet engine?

Answer 36

A steam-powered device that used jet-like thrust principles.

Question 37

What type of airflow does a ramjet rely on to generate thrust?

Answer 37

High-speed ramming air through the intake without moving parts.

Question 38

What speed category must be reached to use a ramjet effectively?

Answer 38

At least twice the speed of sound.

Question 39

Why were jet engines a technological revolution in aviation?

Answer 39

They enabled much faster speeds than propeller engines and redefined military and commercial flight.

Question 40

What wing design is essential for high-speed flight?

Answer 40

Swept wings.

Question 41

Why are swept wings important for fast aircraft?

Answer 41

They reduce air resistance by presenting a thinner profile to oncoming air.

Question 42

What problem do thick wings cause in high-speed flight?

Answer 42

They create massive drag and turbulence that can destroy the wing.

Question 43

Which country first used swept wings effectively?

Answer 43

Germany.

Question 44

What engine type is required for high-speed aviation?

Answer 44

Powerful turbojet engines.

Question 45

What other design feature is necessary for control at high speed?

Answer 45

Large control surfaces.

Question 46

What aerodynamic principle reduces shockwave effects at transonic speeds?

Answer 46

The Coke bottle principle (area rule).

Question 47

Which WWII German aircraft used the Coke bottle design principle?

Answer 47

The Ho 229.

Question 48

What aircraft combined all modern high-speed technologies in one platform?

Answer 48

The canadian CF-105 Avro Arrow.

Question 49

What materials made the Avro Arrow ideal for supersonic flight?

Answer 49

Titanium, which handles heat and stress at high speeds.

Question 50

What kind of computer did the Avro Arrow have onboard?

Answer 50

A targeting computer that could locate and lock onto enemy bombers.

Question 51

What was unique about the Arrow’s flight control?

Answer 51

Minimal human intervention was required; the system was semi-automated.

Question 52

What speed could the Avro Arrow achieve in test flights?

Answer 52

Mach 1.9 in level flight.

Question 53

What was the projected speed of the final Avro Arrow with new engines?

Answer 53

Mach 3.

Question 54

Who was the Canadian Prime Minister that canceled the Avro Arrow program?

Answer 54

John Diefenbaker.

Question 55

Why did Diefenbaker cancel the Arrow?

Answer 55

He wanted resources allocated to more practical needs for Canadians.

Question 56

What concern led to the Arrow being not just canceled, but destroyed?

Answer 56

Fear of Russian or foreign powers accessing the technology.

Question 57

What is one theory about the U.S. role in the Arrow’s cancellation?

Answer 57

That the U.S. pressured Canada to maintain its monopoly on military tech.

Question 58

What happened to the remaining Avro Arrows after cancellation?

Answer 58

They were all dismantled and cut into pieces.

Question 59

What aircraft broke speed records and succeeded the Arrow in performance?

Answer 59

The Lockheed SR-71 Blackbird.

Question 60

What was the top speed of the SR-71 Blackbird?

Answer 60

Over 3,500 km/h.

Question 61

What materials was the Lockheed SR-71 constructed from?

Answer 61

Titanium.

Question 62

What type of propulsion system did the SR-71 use?

Answer 62

A hybrid turbojet and ramjet engine system.

Question 63

Why did the SR-71 drip fuel on the ground?

Answer 63

It was built with loose fittings that expanded in flight due to heat.

Question 64

What design feature helped SR-71 handle hypersonic speeds?

Answer 64

Intentionally leaky construction that sealed tight during flight expansion.

Question 65

Why didn’t the SR-71 need weapons?

Answer 65

It was too fast for enemy missiles or jets to catch.

Question 66

What new problem does aviation now face at high speeds?

Answer 66

Human bodies cannot withstand the G-forces or accelerations.

Question 67

What must be removed to continue pushing aviation limits?

Answer 67

Human pilots.

Question 68

What time did the SR-71 take to cross the Atlantic?

Answer 68

Approximately 1 hour.

Question 69

How long did it originally take to cross the Atlantic before aviation?

Answer 69

About 1 month.

Question 70

What is now considered the main limiting factor in aviation?

Answer 70

The human body and its tolerance to speed and stress.

Question 71

Where did aviation as a transformative technology originate from?

Answer 71

Military needs and defense requirements.

Question 72

Which era marked aviation’s turn toward rapid technological growth?

Answer 72

The 1930s.

Question 73

Which country drove aviation’s military development in the early 20th century?

Answer 73

Germany.

Question 74

What kind of platform was the Avro Arrow hoped to become beyond aviation?

Answer 74

A spaceflight platform.

Question 75

Why was titanium ideal for aircraft like the Arrow and SR-71?

Answer 75

It withstands extreme heat and pressure at high speeds.

Question 76

What happened to the Arrow 206, which was equipped with new engines?

Answer 76

It was ready for Mach 3 tests but was canceled before flight.

Question 77

What does the SR-71 prove about the potential of aviation?

Answer 77

That speed and technology are no longer the limit—humans are.

Question 78

What global context influenced nearly all aviation advances?

Answer 78

Cold War and military rivalry.

Question 79

What principle did all Cold War aircraft design revolve around?

Answer 79

Outpacing the enemy in speed, reach, and technology.