Jun 30

Basic Flight Maneuvering

What is Basic Flight Maneuvering?

Basic Flight Maneuvering, or BFM, is a term used broadly to describe maneuvers that can performed in space. Nearly every task in Star Citizen is going to require some sort of ship maneuvering. This course will serve as a foundation for combat applications, which will be found in later guides.

The Turn

The most basic maneuver that can be performed is a “turn”. This is not to be confused with simply rotating your ship. A turn is a realignment of your velocity vector; in other words, it’s simply an acceleration. A “turn” typically implies that you already have some velocity relative to the inertial reference frame for the given area – in the other case (starting from standstill relative to the reference frame), you are merely thrusting in a direction. Velocity is relative in space, but in the game, Cry Engine does have a stationary reference frame, which the gamecode uses to calculate interactions and events.

bfm1
A hornet moving at 200 m/s. Note that velocity has a magnitude (200 in this case) and a direction (indicated by TVI).

 

In aerial combat, various forms of turns are differentiated by which direction relative to the surface of the Earth the acceleration is occurring. These include the Immelman, the Split-S, various kinds of yo-yos, and so on. Because all objects in Arena Commander are either in free fall or in areas of low gravitational influence, the direction of turn relative to the Cry Engine reference frame itself does not matter and all turns can, for the most part, be considered equal with respect to energy states. Despite this, there are considerations relating to ship and human performance that must be accounted for. Some of these considerations include:

  1. Turns (accelerations) in the ship’s vertical direction (resulting from pitching turns) tend to produce adverse g-force effects on the pilot quicker than turns in the lateral direction or accelerations in the longitudinal direction.
  2. Some ships accelerate better laterally, vertically, longitudinally, or even diagonally due to the thruster layout of the ship.
  3. Some directions of turn relative to the ship are more advantageous for keeping certain objects (like an enemy) in view. For example, aligning an enemy’s movement diagonally can be conducive for those using rectangular displays due to screen diagonal length being greater than lateral or vertical length.

It is important at this point to note that, in the normal (coupled) mode, most of the ship’s accelerations or turns are performed by the IFCS rather than in response to direct inputs by the pilot. An understanding of this concept is critical to being able to properly control a spacecraft, rather than allowing it to control you.

Examples

At full throttle, pitching up is a direct input by the pilot to merely rotate the ship; the ship’s IFCS is responsible for accelerating the ship to align its velocity vector with what it considers the pilot’s intended direction of movement to be (forward relative to the nose). This could include acceleration in more directions than one would usually consider; a simple turn could result in the ship accelerating either forward or backward, for instance.

bfm2
A graphical depiction of a 90-degree pitching turn in coupled mode. Note that the IFCS automatically accelerates forward and upward as needed to realign velocity vector with the nose of the spacecraft.


New directions of flight can also be commanded by using strafe inputs. Consider a pilot who is moving forward at full throttle without strafing. If he were to strafe right, he isn’t directly inputting a turn (acceleration) command into the ship; he’s merely giving the IFCS a new desired direction of travel. The IFCS then executes the accelerations (via various thruster firings) to meet the demand. In this case, despite the additive nature of the throttle (which is equivalent to a “strafe forward” input), it oddly will result in the IFCS firing retro thrusters to arrest some forward movement so that the vector can be shifted to the right without increasing its magnitude. This is because the ship was already at the maximum speed limit permitted by the IFCS (if this doesn’t make sense to you, it may be good to review some trigonometry. Note that if you start at the top of the circle with 100% forward velocity and shift the vector right, to maintain the same maximum magnitude, forward velocity must decrease. Hence, the retro thrust.)

bfm3
A hornet traveling at maximum velocity forward (using throttle or forward strafe, it doesn’t matter) adds a right strafe input. The result is backward and right acceleration.

Ready to start practicing? Here are some exercises that help to apply the information you just learned:

Watch Exercise BFM 1-1:  Orbiting, Strafing

Watch Exercise BFM 1-2:  Station Weaving

 

G-effects​

These quirks of the IFCS and spaceflight in general can become more apparent when the effects of g-forces on the player’s avatar begin to come into play. In the former example, it’s easy to forget that the pitching is not what causes the massive g-force on the avatar and consequently grayout/blackout/g-loc. The ship’s IFCS is causing the g-effects, because it is accelerating the ship to meet what it interprets the pilot’s new desired course (velocity vector direction) to be. What happens to many new pilots is that they will begin a pitching turn, see the grayout beginning, recognize what is happening and stop pitching. Remember, though, that halting pitching does not necessarily stop the ship from accelerating; it merely stops the pitching. The IFCS will continue to accelerate the ship vertically to match the new desired velocity vector unless the pilot takes some action to order a new desired vector direction (for example, strafing downward, or even decoupling).

Though it appears counterintuitive, stopping the pitching turn can actually, in some situations, exacerbate the g-effects further than what would have occurred if the pilot had simply continued their turn. This typically occurs if the pitching turn is stopped before reaching ninety degrees of heading change. At ninety degrees, acceleration to match the desired velocity vector stops being required in the vertical direction and starts becoming more necessary in the longitudinal direction. Since the human body (and, more importantly, the avatars in Star Citizen) can handle many more g’s in the eyes-in direction, this results in less and less blackout for pitching turns once ninety degrees of heading change is reached. The downside is that this larger turns (particularly with COMSTAB off) often result in a momentary loss of velocity, which can make ships more vulnerable to fire.

Source: Erik “The Cat” McKetten’s BSVC Flight School.

Another aspect of the realistic g-force modeling in Star Citizen that may confuse new pilots is the physiological reserve. The physiological reserve represents a real-life resistance humans have to g-effects over short durations. A reserve of oxygen in tissue allows the brain, vision, and other functions to continue normally. On the graph above, you’ll see that it is far worse to carry sustained or increasing g’s over a period of time than it is to quickly pull a large amount of g’s. In other words, it can be beneficial to make sharp, high-g, short duration turns over slow, gradual, low-to-moderate-g turns. Just like in the previous explanation, this can cause inexperienced pilots quite a bit of confusion when they begin to grayout, stop rotating (remember that the IFCS continues to accelerate the ship), and then blackout anyway – but when performing the same turn quickly and without letting off, a G-LOC is avoided.

Your Ship is a Gimbal

One thing to remember is something that was mentioned in General Flight Mechanics: that, for the most part, ships in Star Citizen can be rotated via pitch, yaw, or roll inputs, mostly independent of any turning that the ship’s IFCS is performing. Getting accustomed to using strafe inputs to continue to affect desired turns while pointing the ship’s nose independently is certainly a key to mastering flight maneuvering, and is invaluable in combat.

 

Three (main) types of turn

A simple example of this is the instantaneous turn, which will be covered in the exercises associated with this course. The instantaneous turn, when performed in the vertical direction, is certainly able to produce rapid g-effects on the pilot. A way to counter this is to roll ninety degrees after finishing the rotation so that the acceleration is now being incurred laterally rather than vertically.

To perform an instantaneous turn:

  1. DECOUPLE using CAPSLOCK by default.
  2. ROTATE using pitch and yaw.
  3. RECOUPLE and ROLL simultaneously (rolling is optional depending on direction of rotation and risk of g-effects).
  4. BOOST, BOOST, BOOST (default is shift) to accelerate in the new direction.

An instantaneous turn is a very flat maneuver by itself and can be dangerous if performed for more than ninety-degree turns, but adding lateral strafe while rotating can reduce the risk of taking fire.

In addition to the instantaneous turn, there are two other methods for increasing the rate at which a ship can maneuver. The first is a braking turn, and the second is a boosted turn.

A braking turn is just what it sounds like. By either using spacebrake or reducing throttle just prior to or during a turn, you are, in effect, shortening your velocity vector. This makes it much easier for the ship’s IFCS to realign it, as less acceleration is required. COMSTAB automatically performs braking turns when required.

A boosted turn is also just what it sounds like. By using boost, you are enabling the overdrive feature of the thrusters and (momentarily) giving them more accelerative capability; beware, however, because the other action the hitting to boost key causes is disabling the ship’s g-force safety system (if it was already enabled). This means that boosted turns more often result in G-LOC. Additionally, remember that even after nose rotation has stopped, the ship may still be accelerating the ship laterally or vertically. As a result, using the boost key after stopping the nose rotation can also force a G-LOC. You have been warned.

New pilots should practice all three types of turns in various directions to get accustomed to their use and the performance characteristics of their ships. The exercises associated with this course will cover all three.

Want to give it a shot? Here’s the exercise video:

Watch Exercise BFM 1-3:  Instantaneous Turns

 

Pursuit Curves

The last section of this course introduces the concepts of lead and lag pursuit.

Lead and lag pursuit can be used for a variety of applications, from staying in position near your wingman to maintaining an advantageous position against a fleeing or unaware enemy fighter. The concept is simple and fairly intuitive.

Source: Gladius Flight Manual S1-P5G-UFM-000 by Nimrod_77
Source: Gladius Flight Manual S1-P5G-UFM-000 by Nimrod_77

Lead pursuit is simply aiming ahead of your target, or to the inside of his turn. By doing this, you are reducing the distance to get to a future position of his and, if done correctly, you will fly a shorter distance than he will, resulting in a decrease in range. So, lead pursuit can be used to reduce the range to a moving object – even if you are at a speed disadvantage. If you use lag pips, to pull lead pursuit, you should maneuver to place the lag pip between your gun cross (nose) and your target. If you use lead pips, maneuver to point your nose ahead of the target lead indicators.

Lag pursuit is the opposite. By flying to a point behind your target or simply outside of his turn, you are flying a longer path than he is and range will increase. If you use lag pips, to pull lag pursuit, you should maneuver to place the gun cross between the lag pip and your target. If you use lead pips, maneuver to point your nose opposite of your target from the lead indicators.

A super-simplified way to remember how to pull lead or lag pursuit (if you use lag pips) is:

“Lead pursuit, pip in the middle. Lag pursuit, cross in the middle.”

Pure pursuit is simply pointing right at your target. Your mileage may vary, but generally little change in range will occur.

Think of a football player running down the field with a ball. A defender on the opposing team is on the same yard line, but laterally distant from the ball carrier. In order to catch his target, the defender must choose an intercept point down the field, in front of the ball carrier. Running straight at the ball carrier (pure pursuit) would undoubtedly result in never catching him unless the defender was far faster than the ball carrier; however, running toward where the ball carrier will be in a few seconds has a surer chance of a successful intercept.

It’s important to note at this point that, as stated previously, ships can move independently of their orientation. Consequently, the target arrow at the front of the target box isn’t always a reliable indicator of where to aim for lead pursuit. Looking at the lag pips or target lead indicators can give a more accurate indication of where the ship is moving (or, in the case of the lag pips, where the ship is moving from).

Additionally, the pursuer can fly sideways as well – in this case, instead of putting one’s nose in corresponding position for the desired pursuit type as described above, the pursuer can instead manipulate his or her TVI into that position to effect the pursuit angle.

Now find a buddy and practice some Tail Chase! Exercise video:

Watch Exercise BFM 1-5:  Tail Chase

Watch what it looks like from third person

 

Summary

Because of the (effective) lack of gravitation and drag effects, basic maneuvering in space can simply be described as various types of turn. A complete understanding of the characteristics, advantages, and disadvantages of each will help later when learning combat maneuvering, or, possibly, during other gameplay areas.

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7 comments

  1. DrPeppiX

    Heya !

    Awesome guide man !
    If its okay, i would like to translate it for my members into german to train them :)

    greetings

    Pep

    • Vin

      Sounds great! There’s actually another org doing a Spanish translation as well. Glad that we have the opportunity to be read by more people.

  2. […] week we’ve taken a closer look on two topics we’ve covered before – pursuit angles and skidded attacks. Why these two? Well, quite simply, combined they can help you counter some of […]

  3. SPANXY

    Amazing write up!

    Thanks a lot f sharing his knowledge.

    I had no idea this can get so complex. My mind age been opened to the possibilities and to how much training I’ll have to do to get descent in the verse.

    Cheers! Keep these coming !

  4. Dusti

    Thanks Vin!

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