Grazing bullets

[Pursuivant]

AFAIK, angle at which a bullet strikes an airplane only matters when determining armor penetration and whether you get a "critical hit" by striking some vital part of the aircraft.

IL2 actually has poor damage modeling by modern standards. Airframe damage appears to be handled as "hit points" which trigger increasingly battered-looking skins for a given part of the aircraft, regardless of where and how a particular bullet strikes.

That is, rather than showing where a given bullet hits, damage above X level triggers the D1 texture for a given aircraft part, damage above Y triggers the D2 damage texture, and damage above Z triggers breaking parts/destruction.

Spark/debris effects are triggered regardless of what sort of round hits or where it strikes and have little or nothing to do with levels at which D1, D2 or breaking parts effects are triggered.

The "white rod" you see in Invulnerable mode actually is an arrow which shows exactly where and how a given round hit. It is possible to trigger this effect without being in Invulnerable mode, but I forget the exact command off the top of my head. In the past I've found it very handy for testing damage modeling and for practicing my gunnery offline.