Missile flight

A guided missile in Broken Arrow falls for a moment after launch, burns its motor to speed up, then coasts and slows until it is destroyed at 30% of its top speed. From the game's code It can die sooner, for example if it loses its target or its shooter stops supporting it. From the game's code Whether it hits is decided by a roll, not by the chase. From the game's code

The motor

A missile's flight follows four stages: From the game's code

1. Before ignition it falls, its fall speeding up by 10 each second, for its ignition delay (MainEngineIgnitionDelay).
2. While the motor burns it gains its Acceleration each second, up to its top speed (MaxSpeed), for BurnTime seconds.
3. After burnout it loses 13% of its top speed every second.
4. At 30% of its top speed it is destroyed. The game calls this LostEnergy.

A missile that reached its top speed therefore coasts for about 5.4 s before it is destroyed. Worked out by this site

The plane-launched AMRAAM shows the numbers. The first four come from its row in the data: From the game's data

The last two follow from the top speed: 13% of it and 30% of it. Worked out by this site

Launch speed matters. An AMRAAM that leaves the rail at 350 or more, in the data's speed units, reaches 1150 by burnout and then coasts 5.4 s. One that left at rest would reach only 800 by burnout and be destroyed about 3 s later, some 7.5 s after launch. Worked out by this site

Launch speed

A missile starts at the shooter's speed times the cosine of the angle between weapon and shooter, plus the round's own MuzzleVelocity. From the game's code So a missile fired straight ahead keeps all of the shooter's speed, and one fired at an angle keeps less. Worked out by this site

Most ground anti-air rounds have a MuzzleVelocity of 0 to 100, so a ground missile starts near rest, but not at rest. From the game's data The duel times a missile's flight from a standing launcher. Worked out by this site

Can you outrun a missile?

Only by staying out of its reach until it slows to the 30% cutoff. From the game's code A missile still on course keeps steering while it coasts, and the roll decides the hit, not the motor. From the game's code So unless the missile dies first, the outcome is settled by its rolls: the first when it registers its target, and a re-roll each time the target's count of burning decoys rises before impact. Worked out by this site

Running can still help. A missile gets only the decoy re-rolls that come before its impact, so a longer chase gives your decoys more chances to make it roll again. Worked out by this site On a plane, only the first three decoys are certain to cause a re-roll. From the game's code How that works is in missile hit chance.

Seekers

The seeker type says how a missile is guided. The names are the game's: From the game's data

A round with seeker 0 has no seeker: it is unguided. In the data, every round with a seeker flies the guided trajectory and no round without one does. From the game's data In the current data, 74 rounds are semi-active, 27 terminal guidance, 25 fire-and-forget and 6 anti-radar, and 508 have seeker 0. No round uses type 300. From the game's data

Terminal guidance and semi-active seekers need the shooter to keep guiding the missile. From the game's code That ties them to the shooter twice: its stress lowers their hit chance, and they die if it stops supporting them. From the game's code

Why a missile dies early

The game destroys a missile before its motor runs down for any of these reasons: From the game's code

In player terms: a terminal-guidance or semi-active missile lives only while its launcher supports it, and a launcher that switches to a target outside the missile's cone kills its own missile. From the game's code

Flare resistance

A missile's flare resistance enters its hit roll once for every burning decoy. From the game's code Every guided round has 0, except two with 1.0: the Hydra Fletcher, an anti-air APKWS rocket, and the Khrizantema thermobaric missile. From the game's data These units carry them:

160pts

Stryker M-SHORAD

Stryker Cavalry regiment

60kin front

100best pen

100km/hspeed

With a loadout option

60pts

Kornet-T

Mechanized Infantry

100kin front

1000best pen

70km/hspeed

With a loadout option

40pts

LMTV War Pig

Special Operations Forces

10kin front

20best pen

95km/hspeed

With a loadout option

As the formula is written, resistance 1.0 makes the hit chance 0 whenever a decoy burns. From the game's code That looks backwards for a field with this name, and what happens in play is not known. Not known: our best reading

Reading a missile's columns

The game's data gives each missile a row of columns. Here are the plane-launched AMRAAM's, in player terms. A "code" mark means the game's code was read using the column; a "data" mark means its meaning comes from the column's name.

Active protection stops only rounds marked CanBeIntercepted. From the game's code

Still unknown

• A missile's turn rate. The code reads RotationSpeed; that it is in degrees per second comes from its name only. Not known: our best reading
• When a shooter stops supporting its missile. The exact conditions were not traced. Not known: our best reading
• Flare resistance, as above. Not known: our best reading
• Speed units. The data gives a missile's speeds without a unit, so this page does not compare them with an aircraft's top speed in km/h. Not known: our best reading