HISTORY OF AVIATION

Ford Trimotor - Aircraft Model

Commemorative Stamps on Aviation

100 Years of Airmail

First Airmail Service in the World

History was created on February 18, 1911 when Henri Piquet took off in a Humber Biplane from the right bank of the Yamuna at Allahabad crossing over to the left bank and dropped a mail bag containing 6500 letters and Post Cards at the Naini Railway Station. India thus became the first country in the world to fly air mails. After this pioneer effort, India was also the first country to introduce air mail Post Card in 1931. The first Regular airmail service which was started in 1920, operated between Mumbai (Bombay) & Karachi.

India Post has been commemorating these historic events by issuing sets of postage stamps from time to time. Some of the important stamps issued in past are:
1. First Airmail Post Golden Jubilee (set of 3 stamps) – 1961
2. Air Mail (set of 4 stamps) – 1979
3. 75^th Anniversary of 1^st Aerial Post (set of 2 stamps) – 1986
4. 150 years of India Post – 2004
5. India Post Freighter – 2009.

First Aerial Post Golden Jubilee (1911-19610 - Commemorative Stamps

First Airmail Post Allahabad Feb 18, 1911 - Henri Piquet Postage Stamp released by French POST

Flying Principles

Aircraft rudders

On an aircraft, the rudder is a directional control surface along with the rudder-like elevator (usually attached to the horizontal tail structure, if not a slab elevator) and ailerons (attached to the wings) that control pitch and roll, respectively. The rudder is usually attached to the fin (or vertical stabilizer), which allows the pilot to control yaw about the vertical axis, i.e., change the horizontal direction in which the nose is pointing. The rudder's direction in aircraft since the "Golden Age" of flight between the two World Wars into the 21st century has been manipulated with the movement of a pair of counter-moving foot pedals by the pilot, while during the pre-1919 era rudder control was most often operated with a center-pivoted, solid "rudder bar" that usually had pedal and/or stirrup-like hardware on its ends to allow the pilot's feet to stay close to the ends of the bar's rear surface.

Elevators

Elevators are flight control surfaces, usually at the rear of an aircraft, which control the aircraft's pitch, and therefore the angle of attack and the lift of the wing. The elevators are usually hinged to the tailplane or horizontal stabilizer. They may be the only pitch control surface present, and are sometimes located at the front of the aircraft (early airplanes) or integrated into a rear "all-moving tailplane", also called a slab elevator or stabilator.

Aileron

An aileron (French for "little wing" or "fin") is a hinged flight control surface usually forming part of the trailing edge of each wing of a fixed-wing aircraft. Ailerons are used in pairs to control the aircraft in roll (or movement around the aircraft's longitudinal axis), which normally results in a change in flight path due to the tilting of the lift vector. Movement around this axis is called 'rolling' or 'banking'.

Aircraft Radial Engine Working Principle

Philately exhibiting Aviation History and evolution of aircrafts upto end of World War II

Transition to Era of Jet Engines

A jet airliner or jetliner is an airliner powered by jet engines (passenger jet aircraft). Airliners usually have two or four jet engines; three-engined designs were popular in the 1970s but are less common today. Airliners are commonly classified as either the large wide-body aircraft, medium narrow-body aircraft and smaller regional jet.

Most airliners today are powered by jet engines, because they are capable of safely operating at high speeds and generate sufficient thrust to power large-capacity aircraft. The first jetliners, introduced in the 1950s, used the simpler turbojet engine; these were quickly supplanted by designs using turbofans, which are quieter and more fuel-efficient.

1950s

The de Havilland Comet, the first purpose-built jet airliner. The Boeing 707, the first commercially successful jetliner

The first purpose-built jet airliner was the British de Havilland Comet which first flew in 1949 and entered service in 1952, though it was withdrawn from service due to serious structural problems.

Innovations[

The Pratt & Whitney JT3 turbojets powered the original Boeing 707 and DC-8 models; in the early 1960s the JT3 was modified into the JT3D low-bypass turbofan for long-range 707 and DC-8 variants.^[2]

The de Havilland and Tupolev designs had engines incorporated within the wings next to the fuselage, a concept that endured only within military designs while the Caravelle pioneered engines mounted either side of the rear fuselage.

1960s

The 1960s jet airliners include the BAC One-Eleven and Douglas DC-9 twinjets; Boeing 727, Hawker Siddeley Trident and Tupolev Tu-154 trijets; and the paired multi-engined Ilyushin Il-62, and Vickers VC10.

Innovations

The Tupolev Tu-144, the first supersonic jet airliner. The 1960s jet airliners were known for the advancement of turbofan technology, as well as the advent of the trijet design. Jet airliners that entered service in the 1960s were powered by slim, low-bypass turbofan engines, many aircraft used the rear-engined, T-tail configuration, such as the BAC One-Eleven, Douglas DC-9 twinjets; Boeing 727, Hawker Siddeley Trident, Tupolev Tu-154 trijets; and the paired multi-engined Ilyushin Il-62, and Vickers VC10. The rear-engined T-tail arrangement is still used for jetliners with a maximum takeoff weight of less than 50 tons.

Other 1960s developments, such as rocket assisted takeoff (RATO), water-injection, and afterburners (also known as reheat) used on supersonic jetliners (SSTs) such as Concorde and the Tupolev Tu-144, have been superseded.

1970s

The Boeing 747, the first widebody jet airliner. The 1970s jet airliners introduced wide-body (twin-aisle) craft and high-bypass turbofan engines. Pan Am and Boeing "again opened a new era in commercial aviation" when the first Boeing 747 entered service in January 1970, marking the debut of the high-bypass turbofan which lowered operating costs, and the initial models which could seat up to 400 passengers which earned it the nickname "Jumbo Jet". Other wide-body designs included the McDonnell Douglas DC-10 and Lockheed L-1011 TriStar trijets, smaller than the Boeing 747 but capable of flying similar long-range routes from airports with shorter runways. There was also the market debut of the European consortium Airbus, whose first aircraft was the twinjet Airbus A300.

1980s

The Airbus A320 is the first fly-by-wire jetliner. In 1978, Boeing unveiled the twin-engine Boeing 757 to replace its 727, and the twin-engine 767 to challenge the Airbus A300. The mid-size 757 and 767 launched to market success, due in part to 1980s extended-range twin-engine operational performance standards (ETOPS) regulations governing transoceanic twinjet operations. These regulations allowed twin-engine airliners to make ocean crossings at up to three hours' distance from emergency diversionary airports.^[11] Under ETOPS rules, airlines began operating the 767 on long-distance overseas routes that did not require the capacity of larger airliners.

1990s

By the late 1980s, DC-10 and L-1011 models were approaching retirement age, prompting manufacturers to develop replacement designs. McDonnell Douglas started working on the MD-11, a stretched and upgraded successor of the DC-10.^[14] Airbus, thanks to the success of its A320 family, developed the medium-range A330 twinjet and the related long-range A340 quad-jet. In 1988, Boeing began developing what would be the 777 twinjet,^[15] using the twin-engine configuration given past design successes, projected engine developments, and reduced-cost benefits. In addition, Boeing also released a major update on their 747, the 747-400.

Present day

The Boeing 787, the first mainly composite jetliner. The most modern airliners are characterized by increased use of composite materials, high-bypass ratio turbofan engines, and more advanced digital flight systems. Examples of the latest widebody airliners are the Airbus A380 (first flight in 2005), Boeing 787 (first flight in 2009) and Airbus A350 (first flight in 2013). These improvements allowed longer ranges and lower cost of transportation per passenger. Sukhoi Superjet 100 and Airbus A220 (formerly Bombardier CSeries) are examples of narrow bodies with similar level of technological advancements.

Jet Engine Aircrafts - Working Principles of Jet Engines

How a jet engine works

The schematic diagram below shows the process through which a jet engine converts the energy in fuel into kinetic energy that makes a plane soar through the air. (Source : Ian Schoeneberg courtesy of US Navy):

1) For a jet going slower than the speed of sound, the engine is moving through the air at about 1000 km/h (600 mph). We can think of the engine as being stationary and the cold air moving toward it at this speed.

2) A fan at the front sucks the cold air into the engine and forces it through the inlet. This slows the air down by about 60 percent and its speed is now about 400 km/h (240 mph).

3) A second fan called a compressor squeezes the air (increases its pressure) by about eight times, and this dramatically increases its temperature.

4) Kerosene (liquid fuel) is squirted into the engine from a fuel tank in the plane's wing.

5) In the combustion chamber, just behind the compressor, the kerosene mixes with the compressed air and burns fiercely, giving off hot exhaust gases and producing a huge increase in temperature. The burning mixture reaches a temperature of around 900°C (1650°F).

6) The exhaust gases rush past a set of turbine blades, spinning them like a windmill. Since the turbine gains energy, the gases must lose the same amount of energy—and they do so by cooling down slightly and losing pressure.

7) The turbine blades are connected to a long axle (represented by the middle gray line) that runs the length of the engine. The compressor and the fan are also connected to this axle. So, as the turbine blades spin, they also turn the compressor and the fan.

8) The hot exhaust gases exit the engine through a tapering exhaust nozzle. Just as water squeezed through a narrow pipe accelerates dramatically into a fast jet (think of what happens in a water pistol), the tapering design of the exhaust nozzle helps to accelerate the gases to a speed of over 2100 km/h (1300 mph). So the hot air leaving the engine at the back is traveling over twice the speed of the cold air entering it at the front—and that's what powers the plane. Military jets often have an after burner that squirts fuel into the exhaust jet to produce extra thrust. The backward-moving exhaust gases power the jet forward. Because the plane is much bigger and heavier than the exhaust gases it produces, the exhaust gases have to zoom backward much faster than the plane's own speed.

In brief, it can be seen that each main part of the engine does a different thing to the air or fuel mixture passing through:

1) Compressor: Dramatically increases the pressure of the air (and, to a lesser extent) its temperature.

2) Combustion chamber: Dramatically increases the temperature of the air-fuel mixture by releasing heat energy from the fuel.

3) Exhaust nozzle: Dramatically increases the velocity of the exhaust gases, so powering the plane.

What do jet engines look like in reality? The figure below shows a photoshoot of a real turbofan engine, opened up and undergoing maintenance.

Photo: A Pratt Whitney F117 PW-100 jet engine from a US Air Force C-17 Globemaster plane, undergoing maintenance. Photo by Joshua J. Seybert courtesy of US Air Force.

Types of jet engines

All jet engines and gas turbines work in broadly the same way (pulling air through an inlet, compressing it, combusting it with fuel, and allowing the exhaust to expand through a turbine), so they all share five key components: an inlet, a compressor, a combustion chamber, and a turbine (arranged in exactly that sequence) with a driveshaft running through them.

But there the similarities end. Different types of engines have extra components (driven by the turbine), the inlets work in different ways, there may be more than one combustion chamber, there might be two or more compressors and multiple turbines. And the application (the job the engine has to do) is also very important. Aerospace engines are designed through meticulously engineered compromise: they need to produce maximum power from minimum fuel (with maximum efficiency, in other words) while being as small, light, and quiet as possible.

Turbojets

Photo: Early Turbojet engines on a Boeing B-52A Stratofortress plane, pictured in 1954. The B-52A had eight Pratt and Whitney J-57 turbojets, each of which could produce about 10,000 pounds of thrust. Picture courtesy of US Air Force.

A turbojet is the simplest kind of jet engine based on a gas turbine: it's a basic "rocket" jet that moves a plane forward by firing a hot jet of exhaust backward. The exhaust leaving the engine is much faster than the cold air entering it—and that's how a turbojet makes its thrust. In a turbojet, all the turbine has to do is power the compressor, so it takes relatively little energy away from the exhaust jet.

Turbojets are basic, general-purpose jet engines that produce steady amounts of power all the time, so they're suitable for small, low-speed jet planes that don't have to do anything particularly remarkable (like accelerating suddenly or carrying enormous amounts of cargo).

Turboprops

Photo: A turboprop engine uses a jet engine to power a propeller. Photo by Eduardo Zaragoza courtesy of US Navy.

A modern plane with a propeller typically uses a turboprop engine. It's similar to the turboshaft in a helicopter but, instead of powering an overhead rotor, the turbine inside it spins a propeller mounted on the front that pushes the plane forward. Unlike a turboshaft, a turboprop does produce some forward thrust from its exhaust gas, but the majority of the thrust comes from the propeller. Since propeller-driven planes fly more slowly, they waste less energy fighting drag (air resistance), and that makes them very efficient for use in workhorse cargo planes and other small, light aircraft. However, propellers themselves create a lot of air resistance, which is one reason why turbofans were developed.

Turbofans

Photo: A turbofan engine produces more thrust using an inner fan and an outer bypass (the smaller ring you can see between the inner fan and the outer case). Each one of these engines produces 43,000 pounds of thrust (almost 4.5 times more than the Strato fortress engines up above)! Photo by Lance Cheung courtesy of US Air Force.

Giant passenger jets have huge fans mounted on the front, which work like super-efficient propellers. The fans work in two ways. They slightly increase the air that flows through the center (core) of the engine, producing more thrust with the same fuel (which makes them` more efficient). They also blow some of their air around the outside of the main engine, "bypassing" the core completely and producing a backdraft of air like a propeller. In other words, a turbofan produces thrust partly like a turbojet and partly like a turboprop. Low-bypass turbofans send virtually all their air through the core, while high-bypass ones send more air around it. A measurement called the bypass ratio tells you how much air (by weight) goes through the engine core or around it; in a high-bypass engine, the ratio might be 10:1, which means 10 times more air passes around than through the core. Impressive power and efficiency make turbofans the engines of choice on everything from passenger jets (typically using high-bypass) to jet fighters (low-bypass). The bypass design also cools a jet engine and makes it quieter.

Jet Engines of Today

Philately and Jet Age : Jet Aircrafts and Jet Engines