The Aviation Science

Electronic Flight Instrument System 🛩️ An electronic flight instrument system (EFIS) is an electronic display technology on the flight deck display system. 🛩️It usually consists of Engine Indicating and Crew Alerting System (EICAS), Primary Flight Display (PFD) and Multi-Function Display (MFD) display. 🛩️They commonly use a liquid crystal display (LCD) even though they earlier used cathode ray tube (CRT) displays. 🛩️Installation of the EFIS varies greatly this is where a wide-body aircraft is equipped with six or more display units on which flight and navigation data are displayed while a light aircraft is likely to have one unit. ✈️The installation of EFIS follows the sequence ✈️ Displays ✈️Controls ✈️ Data processors 🛩️Basic EFIS contains all the facilities in one unit.... ✈️Display Units- 🛫Primary flight display (PFD) 🛫Navigation display (ND) 🛫Multi-function display (MFD) 🛫Electronic centralized aircraft monitoring (ECAM)/Engine indicatio...

Hydraulic System 🛩️There are multiple applications for hydraulic use in aircraft depending on the complexity of the aircraft. For example, a hydraulic system is often used on small airplanes to operate wheel brakes, retractable landing gear, and some constant speed propellers 🛩️On large airplanes, a hydraulic system is used for flight control surfaces, wing flaps, spoilers, and  other systems 🛩️A basic hydraulic system consists of a reservoir, pump (either hand, electric or engine-driven), a filter to keep the fluid clean, a selector valve to control the direction of flow, a relief valve to relieve excess pressure, and an actuator 🛩️The hydraulic fluid is pumped through the system to an actuator or servo. A servo is a cylinder with a piston inside that turns fluid power into work and creates the power needed to move an aircraft system or flight control. Servos can be either single-acting or double-acting, based on the needs of the system. This means that the fluid ...

🛩️Krueger flaps are lift enhancement devices that are fitted to the leading edge of an aircraft wing. 🛩️Unlike slats or drooped leading edges, the main wing upper surface and its nose is not changed. Instead, a portion of the lower wing is rotated out in front of the main wing leading edge. 🛩️Current Boeing aircraft, and many others, use this design between the fuselage and closest engine, where the wing is thickest. Outboard of the engine, slat flaps are used on the leading edge. The Boeing 727 also used a mix of inboard Krueger flaps and outboard slats, although it had no engine between them. 🛩️Most early jet airliners, such as the Boeing 707 and Boeing 747, used Krueger flaps only. 🛩️The aerodynamic effect of Krueger flaps may be similar to that of slats or slots (in those cases where there is a gap or slot between the flap trailing edge and wing leading edge), they are deployed differently. 🛩️Krueger flaps, hinged at their foremost position that...

🛩️A combustor is a component or area of a gas turbine, ramjet, or scramjet engine where combustion takes place. It is also known as a burner, combustion chamber or flame holder. In a gas turbine engine, combustion chamber is fed high pressure air by the compression system. 🛩️The combustor then heats this air at constant pressure. After heating, air passes from the combustor through the nozzle guide vanes to the turbine. In the case of a ramjet or scramjet engines, the air is directly fed to the nozzle. 𝐀𝐧𝐧𝐮𝐥𝐚𝐫 𝐓𝐲𝐩𝐞 ✈️The most commonly used type of combustor is the fully annular combustor. Annular combustors do away with the separate combustion zones and simply have a continuous liner and casing in a ring. There are many advantages to annular combustors, including more uniform combustion, shorter size, lighter, and less surface area. Annular combustors tend to have very uniform exit temperatures. They also have the lowest pressure drop of the three...

🛩️The CAT gauge indicates the temperature of the air before it enters the carburetor. The temperature reading is sensed by a bulb or electric sensor. In the test cell, the sensor is located in the air intake passage to the engine and, in an aircraft it is located in the ram-air intake duct. The CAT gauge is calibrated in the centigrade scale. This gauge, like many other multi-engine aircraft instruments, is a dual gauge; two gauges, each with a separate pointer and scale, are used in the same case. 🛩️The yellow arc indicates a range from –10 °C to +15 °C, since the danger of icing occurs between these temperatures. The green range indicates the normal operating range from +15 °C to +40 °C. The red line indicates the maximum operating temperature of 40 °C; any operation at a temperature over this value places the engine in danger of detonation. ➡️Subscribe us for more aircraft knowledge and aircraft fact⬅️ ➡️Do Share with your Friends⬅️

🛩️A Machmeter is an aircraft pitot-static system flight instrument that shows the ratio of the true airspeed to the speed of sound, a dimensionless quantity called Mach number. This is shown on a Machmeter as a decimal fraction. 🛩️As an aircraft in transonic flight approaches the speed of sound, it first reaches its critical mach number, where air flowing over low-pressure areas of its surface locally reaches the speed of sound, forming shock waves. 🛩️The indicated airspeed for this condition changes with ambient temperature, which in turn changes with altitude. Therefore, indicated airspeed is not entirely adequate to warn the pilot of the impending problems. Mach number is more useful, and fighters are limited to a maximum operating Mach number. 🛩️An aircraft flying at the speed of sound is flying at a Mach number of one, expressed as Mach 1. 🛩️Mach meter is a compound air data instrument which has two sensors. 🛩️The air speed capsule measures ...

🛫In aeronautics, transonic flight is flying at or near the Speed of sound 343 m/s(1,235 km/h at sea level), relative to the air through which the vehicle is traveling. 🛫A typical convention used is to define transonic flight as speeds in the range of Mach 0.72 to 1.0 (965–1,235 km/h (600–767 mph) at sea level). 🛫This condition depends on the travel speed of the aircraft & temperature of the airflow in the vehicle's local environment. 🛫It is formally defined as the range of speeds between the critical Mach number, when some parts of the airflow over an air vehicle or airfoil are supersonic, and a higher speed, typically near Mach 1.2, when most of the airflow is supersonic. 🛫Between these speeds some of the airflow is supersonic, but a significant fraction is not. 🛫Transonic airspeeds see a rapid increase in drag from about Mach 0.8, and it is the fuel costs of the drag that typically limits the airspeed. 🛫Most notable is the use of swept w...

🛩️In aircraft, a V-tail is an unconventional arrangement of the tail control surfaces that replaces the traditional fin and horizontal surfaces with two surfaces set in a V-shaped configuration. 🛩️The aft edge of each twin surface is a hinged control surface (sometimes called a ruddervator) which combines the functions of both a rudder and elevators. 🛩️Ruddervators are the control surfaces on an airplane with a V-tail configuration. They are located at the trailing edge of each of the two airfoils making up the tail of the plane. 🛩️Ruddervators provide the same control effect as conventional control surfaces, but through a more complex control system that actuates the control surfaces in unison. 🛩️Yaw moving the nose to the left is produced on an upright V tail by moving the pedals left which deflects the left-hand ruddervator down and left and the right-hand ruddervator up and left. The opposite produces yaw to the right. 🛩️Pitch nose up is prod...

🛫A turn is made by banking the airplane. 🛫In any airplane at any airspeed if a constant altitude is maintained during the turn the load factor for a given degree of bank is the same. 🛫For any given angle of bank the rate of turn is varies with the airspeed. 🛫At given airspeed the load factor increases as AOA increases and the wing stall because the AOA has been increased to a certain angle. ➡️Subscribe us for more aircraft knowledge and aircraft fact⬅️ ➡️Do Share with your Friends⬅️

🛫Ceiling refers to the density altitude the aircraft is capable of reaching under a set conditions (configutaion). 🛫Service Ceiling- The service ceiling is the altitude at which the aircraft is unable to climb at a rate greater than 100 feet per minute (fpm). 🛫Absolute ceiling, there is no excess of power and only one speed will allow steady, level flight. ✈️Based on Maximum Climb Rate 🛫Absolute Ceiling - 0 ft/min RoC 🛫Service Ceiling - 100 ft/min RoC 🛫Cruise Ceiling - 300 ft/min Roc 🛫Combat Ceiling - 500 ft/min Roc 🛫RoC- Rate of Climb ➡️Subscribe us for more aircraft knowledge and aircraft fact⬅️ ➡️Do Share with your Friends⬅️

🛫A modern procedure that is widely used is the stabilised approach. 🛫In this case, the aeroplane descends from the lowest holding altitude (LHA) in the arrival stack and adopts a 300ft/nm rate of descent that is maintained all the way to the runway threshold. 🛫This minimises power adjustments and negates the need for the straight and level segment to intercept the glide path from below. 🛫It also reduces fuel burn and although this is not a major saving per flight, when multiplied by the annual total of approached made in an operation, amounts to a significant economy. ➡️Subscribe us for more aircraft knowledge and aircraft fact⬅️ ➡️Do Share with your Friends⬅️

🛫A monocoque structure uses its outer shell to support stresses and loads applied to it, whereas a semi-monocoque structure has an internal "skeleton" of supports and braces to keep its shape rigid and strong. 🛫The vast majority of pressurized aircraft are semimonocoque to help distribute stresses equally along the fuselage during flight. 🛫However, some helicopters use monocoque structure to maximize internal space in the flight compartment. 🛫Monocoque fuselage has its skin holding the skeleton structure together while the semi-monocoque has both the skin and the skeleton holding together. 🛫Semi-monocoque also has "stringers" running horizontally down the plane to help hold the frame together. 🛫The monocoque fuselage also cannot be used for airframes after a certain size (small aircraft with single engine), but the semi-monocoque has been used from single piston engines to commercial airliners. 🛫A monocoque design would also have ...

🛩️All aircraft hydraulic systems have one or more power-driven pumps and may have a hand pump as an additional unit when the engine-driven pump is inoperative. 🛩️Power-driven pumps are the primary source of energy and may be either engine driven, electric motor driven, or air driven. 🛩️As a general rule, electrical motor pumps are installed for use in emergencies or during ground operations. 🛩️Some aircraft can deploy a ram air turbine (RAT) to generate hydraulic power. 🛩️Double-action hand pumps produce fluid flow and pressure on each stroke of the handle. 🛩️The double-action hand pump consists essentially of a housing that has a cylinder bore and two ports, a piston, two spring-loaded check valves, and an operating handle. 🛩️An O-ring on the piston seals against leakage between the two chambers of the piston cylinder bore. 🛩️An O-ring in a groove in the end of the pump housing seals against leakage between the piston rod and housing. 🛩️When the piston is...

🛫A sonic boom is the sound associated with the shock waves created whenever an object travelling through the air travels faster than the speed of sound. 🛫Sonic booms generate enormous amounts of sound energy, sounding similar to an explosion or a thunderclap to the human ear. 🛫Sound travels in the form of wave in all directions. 🛫Imagine that a stationary aircraft has its engine ON , so the sound travels like sphere around the aircraft with each outer lining, representing a wave. 🛫When aircraft moves, the waves ahead of aircraft get compressed, but they do not averlap each other below the speed of sound. 🛫When it travels faster than speed of sound, the aircraft travels faster than these waves and the waves combine to form a single high energy wave called Sonic boom. 🛫This forms cone behind the aircraft called "Mach Cone". 🛫We can't hear the sound when aircraft passes over is , we can only hear it when the base of this cone reac...

🛫The Attitude indicator (AL), formerly known as the gyro horizon or artificial horizon, is a flight instrument that informs the pilot of the aircraft orientation relative to Earth's horizon, and gives an immediate indication of the smallest orientation change. 🛫The miniature aircraft and horizon bar mimic the relationship of the aircraft relative to the actual horizon. 🛫It is a primary instrument for flight in instrument meteorological conditions. 🛫The essential components of the AI include a symbolic miniature aircraft mounted so that it appears to be flying relative to the horizon. 🛫An adjustment knob, to account for the pilot's line of vision, moves the aircraft up and down to align it against the horizon bar. 🛫The top half of the instrument is blue to represent the sky, while the bottom half is brown to represent the ground. 🛫The bank index at the top shows the aircraft angle of bank. 🛫Reference lines in the middle indicate...

🛫In fluid dynamics, Bernoulli's principle states that an increase in the speed of a fluid occurs simultaneously with a decrease in pressure or a decrease in the fluid's potential energy. 🛫A practical application of Bernoulli’s theorem is the Venturi tube, sometimes called a convergent / divergent duct. 🛫The Venturi tube has an inlet which narrows to a throat, and an outlet section, relatively longer, which increases in diameter towards the rear. 🛫The mass of air entering the tube must exactly equal the mass exiting the tube. 🛫At the constriction, the speed must increase to allow the same amount of air to pass in the same amount of time as in all other parts of the tube. 🛫When the air speeds up, the pressure also decreases. 🛫Past the constriction, the airflow slows and the pressure increases. 🛫Mass Flow is dependent on the 𝐀𝐫𝐞𝐚 𝐱 𝐃𝐞𝐧𝐬𝐢𝐭𝐲 𝐱 𝐕𝐞𝐥𝐨𝐜𝐢𝐭𝐲 and is a constant. 🛫This is known as the 𝐂𝐨𝐧𝐭𝐢𝐧𝐮𝐢...

🛫Flaps are a kind of high-lift device used to increase the lift of an aircraft wing at a given airspeed. 🛫Flaps are usually mounted on the wing trailing edges of a fixed-wing aircraft. 🛫Flaps are used for extra lift on takeoff. 🛫Flaps also cause an increase in drag in mid-flight, so they are retracted when not needed. 🛫Extending the wing flaps increases the camber or curvature of the wing, raising the maximum lift coefficient or the upper limit to the lift a wing can generate. 🛫This allows the aircraft to generate the required lift at a lower speed, reducing the stalling speed of the aircraft, and therefore also the minimum speed at which the aircraft will safely maintain flight. ➡️Subscribe us for more aircraft knowledge and aircraft fact⬅️  ➡️Do Share with your Friends⬅️

🛫The center of gravity (CG) of an aircraft is the point over which the aircraft would balance. 🛫Its position is calculated after supporting the aircraft on at least two sets of weighing scales or load cells and noting the weight shown on each set of scales or load cells. 🛫The center of gravity affects the stability of the aircraft. 🛫To ensure the aircraft is safe to fly, the center of gravity must fall within specified limits established by the aircraft manufacturer. 🛫Center of gravity (CG) limits are specified longitudinal (forward and aft) and/or lateral (left and right) limits within which the aircraft's center of gravity must be located during flight. 🛫The CG limits are indicated in the airplane flight manual. 🛫The area between the limits is called the CG range of the aircraft. ➡️Subscribe us for more aircraft knowledge and aircraft fact⬅️  ➡️Do Share with your Friends⬅️

🛫Flight Controls are divided into two main categories 🛫Primary Flight Control Systems -AILERONS AND FLAPERONS -SPOILERS AND SPEEDBRAKES -ELEVATORS -HORIZONTAL STABILIZER -RUDDER. 🛫High Lift Control systems -TRAILING EDGE FLAPS -LEADING EDGE SLATS -KRUEGER FLAPS 🛫Purpose of the primary flight control system (PFCS)- It controls the airplane flight attitude in relation to the three basic axes: - Longitudinal (roll axis) - Lateral (pitch axis) - Vertical (yaw axis) 🛫Roll Control- the roll control uses the ailerons, flaperons, and spoilers to control the airplane attitude about the longitudinal axis. During a bank of the airplane, the aileron and flaperon on one wing move in an opposite direction from the aileron and flaperon on the other wing. 🛫Pitch Control- The pitch control uses the horizontal stabilizer and the elevator to control the airplane attitude about the lateral axis. 🛫Yaw Control- The yaw control uses the rudder...

🛫The electrical power system supplies 235v ac, 115v ac and 28v dc electrical power to the airplane. 🛫These are the power sources:     • Four variable frequency starter generators.         (VFSG).     • Two APU starter generators (ASG).     • Ram air turbine (RAT) generator.     • Main and APU batteries.     • External power. 🛫There are two VFSGs on each engine. They are the primary source of ac power in flight. Additional sources of ac power are the ASGs. 🛫Each VFSG supplies up to 250 kVA and the ASGs provide up to 225 kVA. 🛫A RAT generator is a source of backup ac power. It supplies 230v ac power up to 10 kVA. 🛫For ground operations, there are three external power receptacles. ➡️Subscribe us for more aircraft knowledge and aircraft fact⬅️ ➡️Do Share with your Friends⬅️