Seven-g F/A-18 fighter Forum

Official Seven-g Forum

You are not connected. Please login or register

Info for beginners

View previous topic View next topic Go down  Message [Page 1 of 1]

1 Info for beginners on Sun Apr 18, 2010 5:49 am


Here is a document on the environment of f18.
This document provides information for beginners who are stepping for the first time into an F18's cockpit .
This tutorial is based on the Jane's game. And it's Rogny, French pilot who did it! Thanks to him.
The English translation is automatic and probably need some improvements.
If these informations seems to be importants for you I will continue the translation as my possibilities.
I think that reading this document will better appreciate the work of 7g


Whether in swirling dogfights with MiGs or to guide a weapon Guided Precision (Precision Guided
Ammunition - PGM) to hatch a enemy destroyer, the air combat is often a struggle to take individual advantage over the opponent. Understanding how and why the device works is a key to success.
Subsection flight mechanics explains the basic principles of flight. Subsection addresses the load factor Mechanical shift, load factors, the flight envelope and how to maximize performance while cornering. The paragraph describes the flight controls rudder of the aircraft and how to use them to maneuver.

To navigate in space, it is essential to master some concepts outlined below:


The flight is the result of four forces acting on the aircraft. Two foster aircraft flight (thrust and lift) and two others are engaged against the flight (weight and drag). The first is the weight of the device, or the force of gravity drawing him to the ground. The second is the thrust , the force produced by the reactor that powers the device in the air. This Forward movement is that air circulates around the wing, creating lift, which opposes gravity. Last force acting on the aircraft drag, which opposes the movement of the aircraft in the air.

Reactor General Electric F414-GE-400, F/A-18 SuperHornet:

Create the thrust is the main function of the reactor unit. This force enables the device to overcome the inertia that is to say, the tendency of an object to resist change in motion. The thrust creates the forward movement which allows the wings to create lift. Both engines General Electric F414-GE-400 afterburning with the F18 Super Hornet can each develop around 22 000 pounds of thrust (9 977 kg) and with a weight ratio of 9 / 1.
For equipment, a common measure is the weight ratio (thrust to weight ratio). Is a comparison report expressed in pounds or newtons between the total weight of an aircraft and its ability to push. A ratio above 1: 1 indicates that the device can overcome gravity ascenssion vertical. Most devices have a hunting report thrust / weight between 0.7 and 0.9. The F-15 and F-16 have a weight ratio higher than 1 really what they can climb vertically. The Russians built the twin engines of the MiG-29 that has a report thrust / weight greater than 1 when the device is unarmed ... and with a single reactor!. The F/A-18 has SuperHornet about him a weight ratio of 44 000 pounds / 66 = 0.66 at 000 pounds maximum load and 44 000 / 30 567 = 1.44 vacuum.
When the thrust is created, it propels the aircraft forward, causing the air flow around the airfoil. This creates a pressure difference that pushes the wing upward. The surge also causes changes in speed. The more thrust, the greater the airflow around the wing is important and therefore, the greater the difference in pressure between the top and bottom
the upper wing surface is important, and therefore more lift is important, which is discussed below.

The lift is produced when airfoil (wing) moves in the air and separates. Half of the air passes over theabove the wing (the surface) and the other half on the underside of the wing (the underside) and flows along the upper andthe underside.
The basic principle is that of retaining transition time equal, that is to say that two molecules of air enteringsame stream separated by the wing on contact, one through the upper and lower surfaces by the other, must be joined to another wing tip at the same time. The top surface is more curved and therefore, longer than the lower surface (see diagram below), which implies that the air flowing above the wing travels a longer distance than that which passes underneath.
Since the air flowing over the upper surface has a greater distance, it must do so at a higher speed than the air under the soffit (under the principle of equal transition time). The faster flow of air over the upper surface results in a lower pressure compared to that under the soffit. This creates a difference Pressure relief valve or imbalance of forces pressure between the upper and lower surfaces. The resultant force pushes upward, creating lift.

2 Re: Info for beginners on Tue Apr 20, 2010 3:18 am


The lift vector points toward the center of the plane of motion. When combined with thrust vector, the resultant as the flight path:
The shape of the wing creates lift in a different way. The wings of most aircraft are angled slightly toward the above, with the leading edge (anterior to) higher than the trailing edge (back). The angle at which the wing meets the airflow is called angle of attack (or incidence). It should not be confused with the base or slope which is position of the nose over the horizon (see chart below).

There is no unique impact that the pilot can rely on. The desired effect depends on the situation. In some cases, the pilot may want to maximize the range of the device bearing an incidence of approximately 14 units. In other cases, conserve energy during a turn will be his first concern by adopting an incidence between 16 and 22 units. To perform optimal constant energy shift. For acceleration, the greater incidence is between 8 and 10 units.
Note: If the incidence is too high, an alarm sounds in the cockpit. To check the effect, just look at the symbol "alpha" and the number directly juxtaposed in the speed indicated on the left side of the HUD.

Drag is the force that makes the aircraft resists movement in the direction of flight. Any object moving in a fluid (and air is a fluid) produces friction. For the aircraft, drag is caused by the friction of air against the wing it moves forward, and a buildup of pressure due to the air pushing against the surfaces of the aircraft.
The induced drag is a component of the rear lift. More wings produce lift, the more they produce
drag. The wave drag occurs when the camera approaches Mach 1. More pressure is created at the front of the wing that back, resulting in a drag force to the rear. Finally, a parasitic drag includes drag and all other types of drag that are not induced lift.
Whatever the type of drag encountered, the overall performance of the device is directly related to the relationship between coefficient of drag and lift coefficient. Different implications are different levels of lift and drag. Each device has an ideal combination of impact, thrust and lift.

When an aircraft moves through the atmosphere, air flows over the wing and this flow creates pressure. At high altitudes, the air is less dense and less air flows over the wing of the aircraft. A pitot tube measures the pressure of the airflow and allows the flight computer to calculate the speed, taking into account the altitude.
Because the atmospheric density, a difference may exist between the flight speed of a unit at a certain altitude with a push and a constant impact and its speed to another altitude, under the same conditions thrust and impact. For this reason, we speak of speed and true airspeed (true airspeed adjusted relative the air density and altitude).
For example, just imagine being in an aircraft to an altitude of 5 000 feet, flying at 350 knots and a second aircraft flying at 30 000 feet at the same speed. Because the second aircraft flying at an altitude where the air is less dense, pitot tubes both aircraft measure different speeds. The aircraft located at higher altitude speed record less than one at a lower altitude. If the two devices both trying to get somewhere at the same time, they need a universal speed they can compare whatever the altitude. This reading is called speed indicated.
By comparing the speeds indicated, it is possible to determine if an aircraft flies faster than the other. Even when true speeds are different, the speeds listed are identical, the two aircraft will arrive at destination at the same time.

Although the thrust force acting on the speed, impact greatly affects the speed. If the driver tries
keep the aircraft in level flight, it is important to remember that should accompany each change of incidence of change of position of the throttle to keep a constant altitude. A very slow speed (that is to say during takeoffs and landings), the effect of the impact velocity is more pronounced.
As a guideline, we must first use the handle to select the desired effect. Then, adjust the knob of
gas until the plateau is reached (in the game in the indicated airspeed IAS or knots indicated appears in the rectangle on the left side of the HUD, as well as on the attitude indicator in the MFD ADI).

A device is gaining altitude through the lift. Just as speed, altitude can be expressed in different ways.
In the game, the two most important are the altitudes indicated (barometric) and radar. On the panel
front control (UFC), it is possibe to designate one of these altitudes as the default altitude.
The barometric altitude indicates the altitude above sea level (ASL). The radar altitude (AGL) indicates the altitude of the unit above ground level as the aircraft flew over.
The altitude reduces engine performance due to lower atmospheric pressure. As altitude increases,
less air is dense. There are some limits to the height at which an aircraft can fly efficiently. The critical altitude of device is the height at which it can now fly in a normal engine power. At 25 000 feet, the engines of plane does not produce more than half the power they deliver to the sea level

The forces of lift and weight previously discussed can be described in terms of "G". For any object, 1G equivalent to the gravity of this object at sea A device level flight experiences a force of 1G. The Load factors are felt especially in tight corners and hard acceleration, they can be positive or negative.
A positive load factor, in turn, pushes the driver in his seat, while a negative factor load pulls out
his seat. When maneuvering tight high load factor, the core driver has to work to irrigate the advantage brain.
A well-trained pilot can withstand load factors positive 9 to 10 g for a limited time. Beyond these limits, the pilot may suffer tunnel vision narrows to form a "tunnel" of closer and closer. Blood focuses in the lower torso and legs, depriving the brain of blood. The vision begins to undergo a "gray veil" (Vision get drunk) and if the load factor is mainenu or it increases, then the driver will undergo a "blackout" (vision blackens completely and prevents the pilot from seeing). A similar situation called "red veil" occurs when the aircraft is affected too G negative: blood concentrates in the upper parts of the body and the blood vessels of the eyes swell up, causing a "red vision. Normally, this begins after a few seconds of flight-3G or more.
The effects of the black veil and the veil red are simulated in the game for this reason, the pilot must atention to the level of G checking on the HUD. If the unit exceeds the limits of load factor, an alarm will sound in the cockpit.
The F18 was designed to withstand positive and negative limits +7.5 G and-3.0G weighing less than or equal to 42 097 pounds. For higher weights, the limits are reduced to avoid surcontraindre the fuselage. Thus, for a weight than 66,000 pounds, the positive and negative limits are +4.8 G and-1.9g.
The excess of G F/A-18E essentially limits the number of positive and negative G to which the pilot can access the basis of gross weight of the device. When the pilot pushes the aircraft to the limits of acceptable G, solicitations additional are ignored. This is commonly called "being on the limit ».
Due to an aerodynamic phenomenon of unintended rotation of the nose of the unit up (transonic pitchup) the G limiter incorporates a function of reduced transonic load factor (g-bucket) designed to prevent too G important due to transonic deceleration. The excess of G can only seek +5.8 G under the influence of decrease in load factor transonic.
It is possible manually disengage the limiter G for emergencies and obtain an increase 33% of the safety interval is a positive limit of 10 G instead of +7.5 G.

Last edited by chataz on Thu Apr 22, 2010 1:04 pm; edited 1 time in total

3 Re: Info for beginners on Wed Apr 21, 2010 1:49 am


The lift is a function of the speed of the aircraft, its altitude, its angle of attack, and all these factors
combine to produce the flight. The three previous parameters must be considered together when we talk about how whose aircraft maneuvering. Their limits are graphically represented by the flight envelope of an aircraft.
Below is the flight envelope of the F/A-18. When the load factor varies, the curves may also vary. The curve on the graph represents the limits of the envelope to 1G. This is a general description of the performance limitations the F/A-18.
The vertical axis represents the altitude in thousands of feet, while the horizontal axis represents the speed of mach number. The full curves represent the maximum power the device, while the dotted curves represent the military power of the aircraft. Curve 1 (blue) describes the configuration of a device carrying 2 AIM-9 Sidewinders, 2 AIM-120 AMRAAM and 60% internal fuel for a total weight of 42.200 pounds. Curve 2 (red) describes configuration of a device carrying 4 AIM-9 Sidewinders, 2 AIM-120 AMRAAM , an external fuel tank centrally a nacelle ATFLIR and 75% internal fuel for a total weight of 46.500 pounds. When the speed changes with Mach
altitude, the curve fits matched. It is importanty noted the vast difference between these two curves and note also that the aircraft is supersonic only from 15,000 feet, even with a relatively payload
low, and it reaches its maximum speed at 35,000 feet around.

The lift is usually created perpendicular to the wing. The control surfaces: ailerons, elevator and rudder, alter this lift to rotate the aircraft around its cenre of gravity. The pilot uses the rudder to maneuver the aircraft.


The aircraft moves around three axes: the tangage, roll and yaw. These axes are always shown from the point of for the pilot in the aircraft. When the pilot moves the rudder of an aircraft, it creates an action.

Pitch is the vertical movement of the nose of the aircraft. It is controlled by the elevator, the surface horizontal control on the back of the F/A-18. At a pitch maneuver, it is pointed downward or upward. This causes a pressure difference above and below the elevator, which creates lift in direction and, consequently, direct the aircraft's nose up or down.
Roll is controlled by the fins of the aircraft. Since the flaps, ailerons are hinged panels on the wings of device. Unlike flaps, ailerons move in opposite directions one relative to another, increasing the lift a wing and decreasing that of another. The difference in lift that a wing tip falls and the other rises, which causes the roll of the aircraft around its longitudinal axis. The drift of the F/A-18 can also be used to cause roll.
Yaw is the lateral movement of the nose of the aircraft. The pitch, that is to say, the position of the nose compared to horizontally, remains constant while the aircraft turned left or right. The yaw is controlled by the drift the tail of the aircraft.
A combination of movements, which requires action in pitch and yaw on the handle, resulting in a movement coordinated. This movement is around the longitudinal and vertical axes. In contrast, simple movements (yaw or pitch) are not coordinated movements. The lace can be used in connection with the pitch to cause banked turn, for example. Similarly, action on the tail, combined with an action of pitching can create a roll effect.
A coordinated movement is normally intended by the pilot: to make a left turn, the pilot pulls on the handle, tilts slightly to the left and press the left rudder pedal. However, this movement can occur
direct consequence of a movement on the other axes. A coordinated movement can occur unintentionally when a device is at high angles of incidence or a yaw rate too high.

The F/A-18E has 14 control surfaces of primary flight, including leading edge flaps ( LEFs), the trailing edge flaps ( TEFs), fins, both fins binoculars, stabilizers horizontal, spoilers, vents and extensions of edges ( LEX winds). It's more than one person can manage a good day. That is why the pilot has two computers that compile all the data.
To control the tanguage and roll, flaps, the trailing edge flaps, ailerons, and stabilizers can
move symmetrically (one complementing the other, ie when the left aileron moves up and the aileron right moves down the same street) or asymmetric (completely independently of the corresponding controls).
The pitch is controlled by the stabilizers and, under certain conditions, through support to the right or left on the rudder (Rudder toe-in) or the flare of the rudder (rudder flare). Roll is controlled by a combination of fins, stabilizers asymmetric, shutters, and the trailing edge flaps. Both twins are offset drift symmetrically for yaw control.
The device is not equipped with a traditional spoiler. Depending on how the function is performed by spoiler deflection several partial surfaces of primary flight control.

The F/A-18E has a traditional central joystick that controls pitch and roll. Since there is no association mechanics between the handle and flight control surfaces, the force feedback of the handle is simulated by sets of springs and dampers to eddy currents. The handle is also balanced by weights that minimize longitudinal movements resulting from the acceleration during a catapult.
Tilt the stick forward or backward activates the elevator of the aircraft and causes a variation
slope. Pull the handle to the rear handle or decreases the slope (up the nose of the aircraft). Push the handle give the handle forward, increasing the slope (pitching the nose of the aircraft). Tilt the stick to the right or left, or lateral mouvment, control flaps. To tilt the aircraft right or left.
Two rudder pedals provide solicitations for directional controls laces and roll. Sets return springs also provide force feedback to the stresses of lifters.
The spreader device activates the drift and yaw control. Press the right rudder pedal to rotate the nose the aircraft to the drot. Press the left pedal rotates it clockwise. The F/A-18 has a lock rudder at high speed to enable the pilot to maintain control of the device.
The use of the rudder also causes the roll. By operating the drift, most devices on the side where the bow rudder is activated. The roll rate depends on the type of device. The rudders are primarily used to align the firing and release of tendrils.
In the configuration of drive F/A-18F (two-seater version of the model E), a joystick was incorporated in copilot's cockpit is mechanically connected to the control yoke. The rudder pedals rudder pedals were also included in co-pilot cockpit, but they are not mechanically connected to the rudder pedals of the pilot. Solicitation of rudder pedals of the pilot and copilot are combined and integrated into the FCS.

The throttle control engine thrust. Pull the throttle back the engine thrust reduced. Push the throttle forward increases the engine thrust. The maximum power of the reactor, without using the afterburner is called military power. The afterburner is powered after military power. It increases the engine thrust by injecting fuel into the exhaust of the engine and igniting. Increasing thrust is important, but the fuel is consumed much faster. The maximum power with afterburner is called maximum power.

The Flight Control System (FCS - Flight Control System), the F/A-18E is the state of the art systems Increase of Control (Control Augmentation System - CAS) for integrated management of Flight Controls Electric.
What this means is that the driver is seated on the seat of an airplane fabulous. Its computerized flight controls him to allow the bird to the test without much concern.
The FCS has four basic functions: the stability of the device, the control device, the resistance to dropping, and the management of the structural load. It continuously monitors the stability of the device, the latter being slightly by design volatile. The inherently unstable aircraft respond more quickly to solicitations from the pilot, which reinforces their maneuverability.
The FSC also maintains complete control of the device by implementing the basic laws of flight control in response to pilot input. The handle and the pedals are not directly linked to control surfaces such as flippers or fins both twins. Instead, the controls send electrical pulses to two computers digital flight control. These computers are the number two in case one of them fails or is damaged during a fight.
The computer immediately interpret pilot input and send commands to control surfaces appropriate flight for that match, the device pitching or yawing turns. The FSC keeps an eye on pilot input could cause a stall or that would place undue constraints on the important fuselage. If necessary, the FSC has the ability to block pilot input or change.
All this activity takes place behind the scenes, without the pilot does not notice anything out of the ordinary. That's the beauty system. It works hand in hand with the pilot, optimizing flight response to its requests.

The control augmentation system (CAS) operates in two basic modes: Powered Approach (PA) and Up-Auto (AU). The mode selection is dictated by the position of the flap control and the speed of the device.
For flaps full deployed or in an intermediate position and a speed below 240 knots, the CAS rule flight controls in landing configuration and landing (Fashion PA).
For flaps automatically controls the CAS rule-making flight altitude and distance, where the designation AU (Auto-Up).
If flap control is still in the intermediate position or the maximum speed exceeding 240 knots, CAS automatically switches the mode PA and AU. This phenomenon is called back automatic shutters (self flap retract).
As an aid to the pilot mode continuously AU balance the aircraft when the handle is in neutral. This function level flight without the driver having to balance the device itself.
The CAS also monitors closely the statements of pitch, roll and yaw, applying controls or stabilization edge stall the control surfaces to maintain the current flight profile, or to react quickly to pilot input.
Each of the two modes of flight control is optimized for maneuverability while maintaining qualities handling and stall conditions.
There is no place for surprises: predictable responses are the norm, not the exception.

4 Re: Info for beginners on Thu Apr 22, 2010 1:02 pm


The flight characteristics are a set of trends that embody stability and maneuverability of the aircraft. The shape, weight, external loads and integrated flight systems determine the fundamental characteristics of a device flight in a specific envelope. When the changes from the center of gravity, lift, speed and balance occur, the flight characteristics vary. A fully loaded aircraft, moving at Mach 2 at altitude 30 000 feet will not behave the same way as a lightly loaded aircraft moving at 250 knots to 5 000 feet.

The performance of an aircraft in turn reflects its ability to change direction in flight. This is often referred to as the maneuverability. ,The number of G an aircraft can withstand cornering gives an indication of its ability to perform sharp.
The maximum cornering performance of a device are of two types: instantaneous and continuous. Acceleration felt during the turn is the load factor.
The load factor is a component of the centrifugal force caused by the shift. Make a turn increases
acceleration of the aircraft and therefore increases the force of gravity. Higher is the speed, higher is the factor load during the turn.

Ability to turn instaneously. This refers primarily to the improved performance of the device to turn at a given moment
When the speed and altitude range, the ability to turn instant also varies. The lift that can produce
the device is directly related to the performance curve instantaneous.
A Vn diagram is a graphical representation of load factor compared to the speed. Above the benchmark 0G, the pilot produces positive and G below, it produces negative G. The limits of lift and load factor are shown on the graph.

Ability to turn continuously. In a continuous turn, the aircraft maintains a speed and turning radius for specific some time. The load factor must be at least 1G to maintain lift and altitude. At a higher load factor quality improves cornering, but the drag increases. The overall capacity of continuous turn of a device depends its weight ratio and its ability to lift.
Lower speeds give optimal cornering supported. In general, the higher the speed is low (up to a certain point), plus the aircraft rotates faster, which gives authority to the old adage fighter "slow down, get it faster! »
The quality of the curve is measured in terms of angular velocity and turning radius. The angular velocity is the number of degrees per second that a device can reach cornering. A high speed and a lower slope decrease angular velocity. The turning radius is the radial distance necessary to make the turn. The turning radius increases with speed and decreases with high inclinations. A high angular velocity and a small turning radius give better cornering performance.
The incidence affects the quality of the turn. In a turn up (as tight as possible), the incidence should be without close exceed 30 units. In a corner optimum (fastest possible), the intention is to keep the speed by sacrificing the radius cornering. In this type of turn, the incidence is usually lower in the range of 6 to 22 units.

For each altitude, which occurs vited to the maximum lift without causing structural damage in a turnis called optimal speed cornering. The optimum speed of turn gives better cornering, that is to saybetter angular velocity with the smallest radius possible. At the optimal speed cornering, the device knows its bestquality instant turn.
The Vn diagram of the preceding paragraph shows the optimal speed cornering. It should be noted that the optimal speed of shift occurs at a speed that gives maximum lift limits structuralles device.
Optimal Speed of Virage's F/A-18E without payload:

The optimum speed cornering without carrying the F/A-18E is 330 knots. With standard payload, the optimum speed cornering is 450 knots.

Sponsored content

View previous topic View next topic Back to top  Message [Page 1 of 1]

Permissions in this forum:
You cannot reply to topics in this forum