Earlier quoted context omitted.
You'd put the containment armor directly around the engine. It wouldn't take dozens of inches. Whether you use Newton's rule of thumb (penetration ends when the mass of armor displaced equals the mass of the shell that hit it) or more modern rules - a failing turbine disk is neither a precision-engineered anti-armor weapon, nor a heavy battleship shell. I'd bet the plane would still be able to take off, if it made it…
Full containment is probably possible, but it would render the aircraft nearly useless, not just economically uncompetitive. A 70kg chunk of nickel alloy is very dense, and at 800m/s , that’s 20 MJ. Thats about the same as 5kg of TNT, but focused on a small area. For comparison, a modern 120mm artillery shell fired from a tank or similar field artillery has 10-20 MJ of kinetic energy. A couple thousand kg of armour c…
> For comparison, a modern 120mm artillery shell fired from a tank or similar ...
Yes. But when the goal is kinetic penetration of modern armour, they don't use artillery shells. Instead -
https://en.wikipedia.org/wiki/Armour-piercing_fin-stabilized...
- which bear no resemblance to a failed turbine disk. And have about twice the muzzle velocity, which makes huge difference in penetrating a modern armour systems. Ditto their far greater density, vs. nickel alloy.
OTOH, your "A couple thousand kg of armour could likely contain..." seems too charitable. High-bypass jet engines are big. Beyond that, I'm more optimistic about mitigating shocks and such.
A critical parameter here - https://en.wikipedia.org/wiki/A380#A380F The freight variant was to have a 6,400 mile range carrying 150t of payload. So we could squander 25t per engine on disk containment and shock mitigation, and still have a 50t payload. Or a 3-digit passenger headcount.
Bottom line, there is no real-world difference between your "nearly useless" and my "disastrously uneconomical". Neither one will be designed, let alone built.
For the A10, I'd say military priorities would always block full disk containment - because every pound used for that is a pound they don't have for more weapons or munitions or range or armour or fuel or runway length or electronics or whatever. And over most of the 360 which disk fragments could exit a warhog's engines, there's nothing critical which they could hit.