| Feature Article
The Falcon
3.0 Manual Tactics Section - Introduction to Offensive BFM
Edited by Ed "Skater" Lynch
For those of you that are "old
salts" when it comes to flight sims, and for those of
you that are new to flight sims, this article should be of
some value to you. This
is largely a reprint from the manual
of one of the best combat flight sims ever released. Spectrum
Holobyte's Falcon 3.0 was indeed the father of all modern,
"realistic" combat flight sims. The F3 manual was
one hell of a paper weight. Weighing in at something like
seven pounds, the F3 manual was jam packed with information
on flying the sim, and the usage of tactics, and the deployment
of weapons and the employment of the aircraft. Here is a little
jewel from the tactics section. Enjoy!
Credit goes to Microprose /
Hasbro Interactive, Spectrum Holobyte, and the Falcon 3.0
team.
Introduction to Offensive BFM
The ultimate goal of offensive BFM
is to kill the bandit in the minimum amount of time. In order
to accomplish this goal, the fighter pilot must understand
basic offensive maneuvering. It is helpful to think of offensive
BFM as a series of fluid rolls, turns and accelerations. Some
of the maneuvers in offensive BFM have names, but the modern
day fighter pilot thinks in terms of driving his jet into
the control position from an offensive setup, rather than
in terms of executing a series of named "moves"
to counter the bandit's defensive maneuvering. The sustained
maneuverability of a modern fighter has made a "move-counter-move"
discussion of offensive BFM obsolete. This study guide reflects
current offensive BFM thinking.
It may seem obvious, but the primary
reason that you need offensive BFM techniques is to counter
a bandit's turn. When you are behind a bandit who is flying
straight and level, it is a simple matter to control your
airspeed with the throttle and fly around behind him. When
the bandit turns, however, things change dramatically. A turning
bandit will immediately create BFM problems.
In order to stay in weapons parameters
and in control of the bandit, you must stay at his 6 o'clock.
To do this, you must maintain control of angle-off, range
and aspect angle. Remember these terms defined the angular
relationship between two aircraft. The above image shows how
a bandit's turn will change the angular relation-ship between
the offensive and defensive fighter. To control the "angles"
and stay at 6 o'clock, the offensive fighter must also turn
his jet. The below image shows why an immediate turn by the
offensive fighter will not work. If the offensive fighter
goes into a turn to match the defensive fighter, he will just
end up out in front because the center of there turn circles
are offset.
An immediate turn will not work, and
driving straight will not work. A turn of some sort is the
solution to solving the BFM problems of angle-off, aspect
angle and range caused by the bandit's defensive turn. The
problem is twofold-how to turn and when to turn. Let's look
first at the mechanics of turns.
BFM and Turns
BFM has a lot to do with turns.
It is important to under-stand several concepts about turns
in order to be successful at BFM. These include the concepts
of positional energy, turn radius, turn rate, corner velocity
and vertical turns.
Power for Position
"Ps (specific power) for
position" is a concept that is an integral part of BFM.
Fighters have two types of energy: kinetic and potential.
Kinetic energy is simply the velocity or speed at which the
jet is traveling. Potential energy is "stored" energy
that can be converted to kinetic energy. Potential energy
is directly related to aircraft altitude. If a jet is at high
altitude, its potential energy is high. If the same jet is
flying at low altitude, its potential energy is low. Always
remember that you can trade altitude (potential energy) for
speed. Likewise, you can convert aircraft speed back into
altitude or potential energy.
You can also exchange energy for nose
position. Anytime you maneuver or turn a fighter; it "costs"
energy. When you turn a jet at high G, you "spend"
or lose energy. That's the bad news. The good news is that
the defensive fighter also gives up energy to turn and defend
himself.
Turn Radius and Turn Rate
The first two characteristics
of turns are turn radius and turn rate. Turn radius is simply
a measure of how tight your jet is turning. If you are looking
down on the aircraft as it turns, the turn radius is the distance
from the center of your turn circle to the aircraft, measured
in feet.
It is not important that you understand
how to compute turn radius. Just realize that velocity is
squared in the turn radius equation, meaning that turn radius
will grow exponentially based on velocity. The equation also
includes aircraft G's. The more G's that you pull, the tighter
the turn. Still, velocity is squared, so airspeed has a greater
effect on turn radius than G.
Turn rate is the second important
factor for turning the jet. Turn rate indicates how fast the
aircraft moves around the turn radius or circle we just talked
about. It is also described as how fast an aircraft can change
its nose position. Turn rate is measured in degrees per second
and is also dependent on G's and airspeed.
The higher the G in the above equation,
the faster the turn rate. Velocity still remains an important
factor. Notice that G is divided by velocity. If G remains
at maximum, a higher velocity will cause turn rate to decrease.
The reverse is true: a lower velocity will yield a higher
turn rate.
Corner Velocity
You may think that slowing down
to minimum airspeed and pulling as hard as you can is the
best course of action in order to achieve a high turn rate.
Not so fast. There is a relationship between airspeed and
G's. At lower airspeeds, you have less G available or, in
other words, you can't pull as many G's as you get slow. Less
lift is produced by the wings of an aircraft at slower speeds,
and as a result, there is less force available to turn the
aircraft. If you get going really fast (above Mach 1, for
example), you also lose G availability. For every fighter,
there is an optimum airspeed for achieving the highest turn
rate. The airspeed where the jet has the quickest turn rate
with the smallest turn radius is called corner velocity. In
most modern fighters, it is between 400 to 500 KCAS. The F-
16 has a corner velocity of about 450 KCAS.
The next image shows the relationship
between airspeed (labeled as a Mach number), turn rate and
turn radius. The top of the image shows turn rate and turn
radius broken out individually, while the bottom of the graph
shows them combined. These graphs in the image below are generic
turn rate and radius charts. The bottom chart represents the
approximate turn performance of an F- 16.
Note that at 0.6 Mach, the jet can
pull 9 G's and turn at a rate of 24° per second. At 0.6
Mach, the jet can also turn in a radius of 1,500 feet. This
is the best (tightest) radius the jet can achieve at the highest
turn rate possible. The jet can turn this same radius at slower
airspeeds, but turn rate will go down significantly. At 0.4
Mach, for example, the jet can turn with a radius of 1,500
feet, but the turn rate falls from 24° to 16° a second.
Just to put this figure in perspective, a 2° per second
turn rate advantage will allow you to dominate an adversary.
The airspeed of a jet can be controlled
by the pilot in the following four ways:
- Throttle position
- Drag devices
- Nose position in relation to the
horizon
- Aircraft G
Throttle position controls how much
slow, cold air you turn into fast, hot gas. Drag devices refer
primarily to speed brakes. Nose position in relation to the
horizon also affects airspeed. For example, a nose-low position
will increase your airspeed because of the effect of gravity.
Finally, G force causes airspeed to bleed off. Remember the
brief discussion earlier about exchanging energy for position.
No modern fighter flying at medium altitude can stay at corner
velocity while pulling max G's for long. As you pull G's,
you will get slower. It is important, however, to start maneuvering
close to corner velocity because the first turn you make is
usually the most important in the fight.
Fighter pilots should think in terms
of both turn rate and turn radius. A fighter with a superior
turn rate can outmaneuver a fighter that has a poor turn rate
but a tighter turn radius. Fighter pilots have a simple two-word
saying: "Rate kills." What this means is that the
ability to move (or rate) your nose is the primary means of
employing weapons (which is what offensive BFM is all about).
A bandit may have a tight turn circle, but if you can rate
your nose on him and shoot, the fight is over. The flaming
wreckage will no longer cause you BFM problems.
Vertical Turns
I have heard it said (incorrectly)
that you fly in relation to the bandit and not the earth.
While it is obvious that you must fly in relation to the bandit,
you must simultaneously keep your nose in control of the horizon.
Gravity affects airspeed, as already mentioned. Gravity also
affects G availability. If you pull the nose of a fighter
straight across the horizon, gravity will have no effect on
your turn performance. When you pull the nose up or down,
however, gravity becomes a player.
The next image introduces a new term:
radial G. To understand how an aircraft turns, you must understand
that there are two factors that determine the rate and radius
of a fighter's turn. The first is the G being felt and read
out on the G meter in the cockpit. The second is the pull
of gravity. Radial G is a term used by fighter pilots to describe
the effective G that determines a fighter's turn. This shows
this concept by depicting a fighter doing a loop. In the image
below, the cockpit G (the G felt by the pilot) is a constant
5 G's. You will notice that when an aircraft is straight and
level and trying to pull in the vertical, the effective G
or radial G is only 4. Gravity is subtracted from cockpit
G so that the jet is pulling only 4 radial Gs. When the fighter
is pulling 5 G's in the cockpit in the pure vertical (90°
point) either straight up or straight down, gravity has no
effect, so radial G is equal to cockpit G. When the fighter
is inverted and pulling straight down at 5 G's, gravity adds
1 G to your effective or radial G. The fighter, in effect,
is turning at 6 G's at this point. Radial G then is simply
a term that describes the effective or turning G created by
combining the positive or negative influence of gravity with
cockpit G.
What the above image shows is that
cockpit G is not equal to radial or turning G when maneuvering
in the vertical. Remember that 2' per second is a significant
turning advantage. The extra G you can get by placing your
nose below the horizon when you turn can give you at least
2' per second turn advantage. Most of the time, 1 GR equates
to 3°-4° per second.
The concept of radial G can be seen
in our next image. In this image, both fighters are pulling
the same cockpit G. Notice that the fighter with his lift
vector below the horizon is turning tighter. What is not so
obvious in this figure is that the fighter turning toward
the ground is also moving or rating the nose faster.
Turning Room
When a bandit turns his jet,
he creates BFM problems for you. To solve these problems,
you need to turn your jet. In order to turn your jet and solve
these BFM problems, you need turning room. Turning room is
the offset or distance from the bandit. There are three basic
types of turning room: lateral (or horizontal) turning room,
vertical turning room, and a combination of both. In order
to understand the concept of turning room, you must first
understand turn circles. Turn circles are simply the paths
that a fighter cuts through the sky when it turns. Our next
image shows a turn circle.
The concept of turn circles is critically
important to understand because, in order to turn and solve
BFM problems created by the bandit, you must first drive your
jet inside the bandit's turn circle.
Here's how turn circles and turning
room are related.
A bandit turns his jet to defend against
your attack. You need to get displacement from the bandit
in the horizontal or vertical in order to turn and stay behind
him. If you try to get displacement while you are still outside
the bandit's turn circle, it will not work. Why? Because if
you are outside the bandit's turn circle, the bandit can get
around the turn and meet you close to head-on. This means
that the bandit can turn and take away your turning room.
Now we show a fighter turning for lateral offset outside a
defender's turn circle.
The bandit just keeps pulling, leaving
the defender with no turning room. This same principle also
works in the vertical. Next shows a fighter climbing, doing
an old maneuver called a "high yo-yo."
It is very dangerous to try to get
turning room in the vertical, outside the bandit's turn circle.
If you are climbing in the vertical outside or dose to the
bandit's turn circle, the bandit can get his nose around on
you. When you pass at high aspect, the bandit will be nose
high while you will be nose low. The bandit gets the first
use of gravity to increase his radial G as you pass and will
probably get behind you. For this reason, do not try to get
turning room outside the bandit's turn circle.
Any maneuvering you do outside the
bandit's turn circle will delay you from getting inside the
bandit's turn circle. You must be inside the bandit's turn
circle in order to turn and solve the BFM problem. In the
next section, we will describe how to determine if you are
inside or outside the turn circle of the bandit and how to
use BFM to get and stay in weapons parameters.
Solving the Offensive BFM Problem
The reason you are out there
burning jet fuel is simple: to get into weapons parameters
and shoot. BFM is real simple against a guy hanging in a chute.
All you have to do is watch out for him shooting at you with
his pistol as you fly by and wave. Anytime you can take a
shot and end the fight, do it. The problem is that when you
start from 1.0 to 1.5 nm behind the bandit and he turns, you
will only be in AIM-9M parameters for a very short time. The
AIM-9M is just like every other heat missile out there today
it doesnt like the high line-of-sight rates generated
by targets in tight, turning fights. You have time for one
shot. If you miss, you had better be ready to put some offensive
BFM on him, or you will end up wearing an AA- 11 Archer. The
end result of your best offensive BFM will be a gunshot. Here
is how you do it.
The bandit turns. The first question
you must ask yourself is "Am I inside or outside the
bandit's turn circle?"
How do you know? Watch the bandit's
turn.
If the bandit's present turn rate
will force his nose on you or even close to you, you are outside
the bandit's turn circle. For modern fighters at high G, you
are normally outside the bandit's turn circle at ranges outside
2 nm. At 1 nm, you are normally inside the bandit's turn circle,
and between these ranges, you are in a transition zone. These
ranges, of course, do not really matter to a fighter pilot.
When you start behind a bandit, you simply fight what you
see. As the bandit turns, you predict where he is going and
maneuver based on this prediction. For example, if the bandit
is only pulling 4 G's, then at 2 nm you are still inside his
turn circle. The next image shows the difference between starting
at 2 nm from a 4 G target and starting at 2 nm from a 7 G
target.
Most fighter pilots will not pull
only 4 G's, however, when they are in danger of dying. Still,
you fight what you see.
If you are outside the bandit's turn
circle at the beginning of the fight, you are not in an offensive
fight-you are in a head-on BFM fight. Head-on BFM is the subject
of Chapter 4, but for now, just think about an AIM-9M shot
in this situation. The bandit cannot shoot you until he gets
his nose around to within about 40° of your jet. You should
be able to get one good missile shot at him before he forces
you inside Rmin.
Gun Shot Procedures
Flying good offensive BFM against
a bandit will put him right in your gun sights. You'll get
him there by under-standing the dynamics of getting into position,
closing and firing.
Flying into Gun Parameters
It is time to discuss how and
when we turn to stay behind the bandit. You are inside 1.5
nm on a hard turning bandit, and you need turning room to
get around on his six. The first step is to observe the bandit's
turn. If you are outside the bandit's turn circle, get ready
for a head-on BFM fight. If you are near or inside the bandit's
turn circle, you have a positional advantage that you can
keep. Shoot, if a shot presents itself, but don't get mesmerized
watching your own missile and forget to BFM. Next, drive to
where the bandit started his turn. If the bandit drops flares
or chaff, he will mark the point in the sky where he started
his turn. Drive to this position (called the entry window).
Next you'll see the entry window. The entry window is located
inside the bandit's turn circle. You can start your high G
turn into the bandit once you arrive inside this window.
In the below image, the F- 16 drove
in a lag pursuit course to a position inside the bandit's
turn circle. By driving to this position, the F- 16 gained
horizontal turning room that the bandit can't use or take
away. You know you are at the entry window and must start
your turn when the bandit is approximately 30° off your
nose.
When you get into this relationship
with the bandit, start your turn. Remember corner velocity.
If you arrive at the window too fast or too slow, you will
get stuck in lag pursuit because you will not have sufficient
turn rate to get your nose out in front of the bandit.
The next step is to pull 7 to 8 G's
into the bandit. As you come around the corner, keep your
nose in lag. If you see the nose of your jet approaching pure
pursuit, ease up on the G. Hold this lag pursuit course until
you get within 3,000 feet of the bandit. At this range, go
to lead pursuit and get ready for a gun shot.
When you arrive inside 3,000 feet
on the bandit with your nose in pure or lead pursuit, your
throttle controls your overtake. Note this. In close to the
bandit, with your angle-off less than 45° and your nose
in pure or lead pursuit, the position of your throttle controls
your closure. When you get saddled up for a gun shot, you
must match airspeed with the target. In most cases, this will
require constant movement of the throttle. In addition to
banging the throttle off both stops, you may have to maneuver
out of plane to control your airspeed. If a throttle reduction
and the speed brakes dot slow you down enough, roll the jet
to orient your lift vector out of the bandit's plane-of-motion
and pull. Hold this lag pursuit pull for about two seconds;
then ease off the G and watch the bandit. When he starts to
move forward on your canopy, it is time to pull back into
him. Pull your lift vector out in front of the bandit as you
pull down.
Taking a Gun Shot
You are inside 3,000 feet on
the bandit with your nose in lead. How do you take a gun shot?
The gun in most fighters is actually a cannon. The F-16, for
example, has an M-61A1 20mm cannon, which is common to almost
every U.S. fighter. The M-61A1 shoots High Explosive Incendiary
(HEI) rounds at the rate of 100 per second. At the proper
range, the gun is like a giant buzz saw. In order to carve
up the enemy, however, you must understand the fundamentals
of taking a gun shot. To hit a target with the gun, you must
meet the following conditions:
- You must be in range. This range
varies, depending on aspect, but it is usually about 2,500
feet at low aspect angles and about 4,000 feet at high aspect.
- You must have your nose in lead
pursuit. The bullets fired by the gun are unguided projectiles
that take time to get to the target. For most gunshots,
the bullet time-of-flight (TOF) is .5 to 1.5 seconds. If
you point directly at the target and fire, the bullets will
pass behind the target. If the bullet moved at the speed
of light, you could point right at a turning target and
score a hit. Since the bullet is considerably slower, you
must pull lead. This lead may not be very pronounced, however,
at dose range.
- You must be in the bandit's plane
of motion. When an aircraft turns, it carves a circle in
the sky that creates a plane. In order for you to hit the
target with the gun, you must be turning in the same plane
as your target. For example, if the target is flying a loop
and creating a vertically oriented plane of motion, you
have to be flying a loop in the same plane as the target.
Using the Gun Sight
The new gun sight for the F-16
and F-15 is called EEGS. EEGS (pronounced as it is spelled)
stands for Enhanced Envelope Gun Sight. The EEGS funnel allows
the pilot to match the wingspan of the target with the width
of the funnel to determine the proper firing range. The other
important gun aiming cue in the HUD is the gun cross. The
gun cross represents the departure line of the bullets. You
can consider the gun cross as the gun barrel. Bullets pass
straight out the gun cross.
So, how do you use the funnel? The
gun in the F- 16 is boresighted to 6 mils. This means that
the gun is adjusted to fire a burst that will put 80% of the
rounds inside a 6-foot diameter circle at 1,000 feet. This
is a tight pattern. You can have either a highly concentrated
burst that completely misses the target or a very lethal burst
that vaporizes the target. It just depends on the quality
of your gun sight (and your ability to aim it.) Air-to-air
situations are always dynamic, and targets under attack will
normally jink violently to stay alive. Since the sight (and
your reactions) are not instantaneous, it is likely you may
achieve a highly accurate miss; that is, a tight burst that
finds only empty air. The sight was lined up and stable, but
you missed. How could this happen? The sight was lying because
the target was jinking faster than the sight could react.
The way to overcome this problem is to strive for an inaccurate
hit. You do this by using the EEGS funnel to fire a burst
while moving the target through the area of uncertainty. The
EEGS funnel gives you a perfect solution when the wingtips
of the target match the width of the funnel. If the target
is jinking, however, this "perfect solution' may be in
error.
Here is how to use the gun cross /
funnel combination to kill the bandit:
Place the gun cross out in front of
the target. Picture the target with a long pilot boom sticking
out the nose. The gun cross should be placed on this extended
pilot boom. If the target changes his plane-of-motion, then
fly to place the gun cross on the new position of this imaginary
pole sticking out of the nose of the target.
Next, over lead the target by making
the wingspan of the target extend past the funnel. This will
place your bullet stream in front of the target's nose.
Fire the gun while easing up on the
G. This will move the target from the bottom of the funnel
to the top. Cease fire when the target's wings are inside
the funnel.
Make a slight jink out of the bandit's
plane-of-motion so, when he blows up, you don't suck a body
part down your intake.
This technique uses the gun cross
and the EEGS funnel to place the bullet stream in front of
the bandit. When you ease up on the G, the target should fly
through your bullets. Our last image shows how to make this
shot.
Part One: The Geometry
of Air Combat
Part Three: Introduction
to Defensive BFM
Part Four: Introduction
to Head-On BFM
Part Five: Introduction
to the BVR Fight
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