Basic fighter maneuvers (BFM) are tactical movements performed by fighter aircraft during air combat maneuvering (ACM, also called dogfighting), to gain a positional advantage over the opponent.The Ultimate Weaponry, Paddy Griffith, CN 5219 Published 1991 BFM combines the fundamentals of aerodynamic flight and the geometry of pursuit, with the physics of managing the aircraft's energy-to-mass ratio, called its specific energy.
Maneuvers are used to gain a better angular position in relation to the opponent. They can be offensive, to help an attacker gain an advantage on an enemy; or defensive, to help the defender evade an attacker's weapons. They can also be neutral, where both opponents strive for an offensive position or disengagement maneuvers, to help an escape.
Classic maneuvers include the lag pursuit or yo-yo, which add distance when the attacker may overshoot the target due to higher airspeed, the low yo-yo, which does the opposite when the attacker is flying too slow, the scissors, which attempts to drive the attacker in front of the defender, and the defensive spiral, which allows a defender to disengage from an attacker.
Situational awareness is often taught as the best tactical defense, removing the possibility of an attacker getting or remaining behind the pilot; even with speed, a fighter is open to attack from the rear.
Introduction Basic fighter maneuvers (BFM) are actions that a fighter aircraft makes during air combat maneuvering, historically known as dogfighting. The development of BFM began with the first fighter aircraft, during World War I, then continued with each following war, adapting to the changing weapons and technologies.
Basic fighter maneuvers consist of many varying tactical turns, rolls, and other actions to get behind or above an enemy, before the opponent can do the same. BFM are typically universal maneuvers which can be performed in almost any fighter aircraft, and are usually considered to be training maneuvers. Training usually begins with pilots flying the same type of aircraft, pitting only their skills against each other. In advanced training, pilots learn to fly against opponents in different types of aircraft, so pilots must learn to cope with different technological advantages as well, which more resembles real combat. In actual air combat maneuvering, variations of these basic maneuvers may become necessary, depending on the different types of aircraft involved, the weapon systems each side is using, and the number of aircraft involved.
BFM are used in the three-dimensional arena of air combat, where maneuvers are not limited by simple two-dimensional turns, such as during a car chase. BFM not only relies on an aircraft's turn performance, but also on the pilot's ability to make trade-offs between airspeed (kinetic energy) and altitude (potential energy) to maintain an energy level that will allow the fighter to continue maneuvering efficiently. BFM also relies on the pilot's understanding of the geometry of pursuit within the three-dimensional arena, where different angles of approach can cause different rates of closure. The fighter pilot uses these angles not only to get within a range where weapons can be used, but also to avoid overshooting, which consists either of flying out in front of the opponent, called a "wingline overshoot", or crossing the enemy's flight path, called a "flight path overshoot".
The fighter pilot with the most advantageous position is usually above or behind the opponent, and is commonly called the attacker. Conversely, the pilot in the disadvantageous position is usually either below or ahead of the opponent, and is referred to as the defender. Most maneuvers are offensive, such as the "barrel roll attack", "high Yo-Yo", "low Yo-Yo", and "lag roll". Defensive maneuvers more often consist of turning very aggressively to avoid the attacker's guns, with maneuvers like the "break" and the "high Yo-Yo defense"; sometimes tightening the turn, sometimes relaxing it, and other times reversing the turn. The defender will usually maneuver to force an overshoot, or to extend the range enough to dive away and escape. However, other "last-ditch" maneuvers are used by the defender when the attacker achieves a firing solution, or the defender's energy becomes depleted so that maximum turn performance cannot be maintained, such as "guns defense" or the "defensive spiral".
History
Basic fighter maneuver development began during World War I, with maneuvers such as the "Immelmann", named after German pilot Max Immelmann, the "break" and the "barrel roll". The modern Immelmann differs from the original version, which is now called a stall turn or "Hammerhead turn". The Immelmann turn was an effective maneuver in the early part of the war but as aircraft technology advanced and fighter engines became more powerful, it became a dangerous maneuver, because the opponent could climb and shoot the German fighters when they were almost motionless at the top of the turn.
Billy Bishop, the top Canadian ace of World War I, described a break:
During World War I, due to the low power of early aircraft, vertical movements were difficult and extended maneuvering led to a loss of energy. Combat tended to degenerate into individual attacks, the classic "dogfights". One specific maneuver that did emerge was the defensive Lufbery, in which several allied aircraft would fly in a circle so that any attackers trying to position against one of the aircraft would fly directly in front of the aircraft behind them. As engines became more powerful, three-dimensional tactics became available to counter the stalemate of the Lufbery, and by WWII it was no longer effective.U.S. Navy Air Training Command - Air combat maneuvering -- Rolling scissors
Development continued through each war, as aircraft and weapon systems became more advanced. Maneuvers such as the "combat spread" were first devised by pilots like Werner Mölders during the Spanish Civil War. A simple, non-turning form of the low-Yo-Yo is depicted in John T. Godfrey's description of his first kill, flying a Republic P-47 Thunderbolt over Europe during World War II;
Much of the modern energy-management techniques, which are used in maneuvers like the Yo-Yos, were only described scientifically after John R. Boyd developed his energy–maneuverability theory (E–M theory) during the Vietnam War. Even so, as quoted by the U.S Navy Air Training Command, "1) The basics of ACM have not changed since the early days of aviation, and 2) A fighter pilot must maintain constant aggressiveness for success. As the [Red] Baron would say, 'All else is rubbish.'"U.S. Navy Air Training Command - Air combat maneuvering -- Introduction
Training
Basic fighter maneuvers (BFM) are used by fighter pilots during a dogfight to gain a positional advantage over an opponent. Pilots must have keen knowledge of not only their own aircraft's performance characteristics, but also of the opponents, taking advantage of their own strengths while exploiting the enemy's weaknesses. Pilots need good eyesight, situation awareness, and the ability to maneuver against an opponent in three dimensions. BFM are generally grouped into two categories: Primary BFM Relative BFM
Primary maneuvers are those which are performed without respect to an enemy's position. These are often simple maneuvers, such as climbs, turns, aileron rolls, slow rolls, and rudder rolls. Relative maneuvers are performed in relation to the motion of another aircraft. These are often more complex, including energy saving maneuvers, such as the high and low Yo-Yos, and repositioning maneuvers such as displacement rolls. It is easy to fall into the trap of considering BFM to be a series of set maneuvers providing a foolproof recipe for a dominant position. The reality is that BFM are a series of fluid and often improvised proactive and reactive actions, varying infinitely according to range, altitude, speed, aircraft type, weapons system type and any of an enormous range of other factors. An extremely successful tactic one day may yield unfortunate results if repeated the next day, and pilots often credit luck as a major factor.
BFM are normally considered to be individual maneuvers, where ACM is applied to the tactics behind dogfighting as a whole. In military training, BFM are often conducted against an adversary in the same type of aircraft. This allows the pilot to fly against a machine with known performance values and allows aircrew to build their awareness of important concepts such as sight picture, rates of closure and line of sight rates that are cues to being successful in the visual arena. This also allows pilots to build their BFM skills against one another, without either having a particular technological advantage.
Dissimilar air combat training (DACT) consists of advanced maneuvers performed by aircraft of two separate types (such as F-16 vs F/A-18). This training is valuable in that both pilots are not as aware of the performance capabilities and characteristics of the other aircraft and, therefore, must rely on the fundamental BFM principles and evaluation/decision making skills to maneuver to an advantageous position versus their opponent. In this type of training, the advantages of one type of fighter may differ greatly from the advantages of the other, so pilots learn to refine their BFM skills to make use of the opponent's weaknesses. Using BFM as the building blocks for multiple aircraft maneuvers, such as the finger four, loose deuce, and Thach weave, pilots learn how to maneuver in situations involving one against one, one against two, two against two, two against many, or even one against many. This type of training, introduced during the last stages of flight school, is more like actual combat, and is the most beneficial for aircrew once basic BFM skills are mastered.
Principles
Specific energy Energy is a primary factor in controlling and maneuvering an aircraft. If an attacker has too much energy, it may be easy to get in range but difficult to prevent an overshoot. Too little energy and the attacker may not be able to get in range at all. If the defender has more energy than the attacker, an escape may be possible, but too little energy and the defender will lose maneuverability.
In aviation, the term "energy" does not refer to the fuel nor the thrust it produces. Instead, thrust is referred to as "power". Energy is the state of the fighter's mass at any given time, and is the result of the power. Energy comes in two forms, which are kinetic and potential. Kinetic energy is a function of the fighter's mass and speed, while potential energy is a function of its mass, gravity and altitude. The combined potential and kinetic energy is called the total energy. Because the energy package is the combination of mass, speed and altitude, a fighter flying at low altitude but a high speed may have the same total energy as a fighter of equal mass, but flying at a low speed and high altitude.
One of the inputs to the formula for total energy is the mass of the object, in this case the aircraft. This means that two aircraft flying under identical conditions of speed and altitude will have different energy; the heavier aircraft will have higher energy. However, this does not imply that the heavier aircraft will be more maneuverable, as that mass will require more energy to accelerate. For this reason, a more useful measure is the specific energy, the energy per unit weight. Lighter aircraft generally have higher specific energy for any given operational conditions.