Originally posted by Krusty
You can't make a jet engine out of aluminum. Problems with development and production rates of the early jet engines were because the stronger metals were scarcer, harder to work with. They were, however, much stronger than aluminum.
Historically, jet engines were more reliable than props. Less moving parts, less parts in general, much less to go wrong.
I don't know what types of metal were used, or how strong a bullet you need to pierce the engine casing, but simply sucking a bullet into the fan blades shouldn't destroy the engine, nor should a glancing blow take out your oil instantly. There wasn't that much place where the oil was stored, and I would suspect the "hit zone" for causing an oil leak was very small.
In this game it's about half the size of the plane!
I don't think the 262 is modeled right, personally. FM and DM need work, IMO.
(This comes from my 262 books from the Smithsonian restoration project):
The backbone of the Jumo 004 is a complex aluminum casting which provided the engine attachment points, supported the compressor case, the combustion chamber assembly, the turbine nozzle, turbine bearings, and finally the entire exhaust system.
Each of the six combustion chambers was built up of 3 major components - a mild steel outer casing, the flame tube, and a corrugated, aluminized steel liner which ducted cooling air through the outer casing.
Hot gas was ducted to the 61 blade turbine wheel. The turbine wheel was intended from the beginning to have hollow air cooled blades, but the pressure of time had dictated that the first versions have solid turbine blades. The blade was formed from conically rolled sheet metal by folding it and welding it at the trailing edge. The material used, "cromadur" required no precious nickel, was easier to produce, and was more reliable in operation...
The engine burned the noxious smelling german j-2 fuel, which was derived from brown coal.
From the engine breakdown notes:
The eight stage compressor has an amazing variety of types of materials and finishes, ranging from stamped aluminum to zinc-coated sheet steel. Even within a single motor variations were found in the materials and method of assembly of stator blades...
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If you look at a cutaway of the Jumo 004, you see the oil tank is located right at the front of the engine near the starter motor, between the inner & outer castings. A bullet or cannon shell hitting the front portion of the nacelle would have a good chance of either hitting the oil tank or one of the lines leading away from it (and there are many).
As far as the pilot wounding issue goes - I think the damage model needs adjusting there. The 262 cockpit is a steel bathtub which is completely fitted out with controls, instruments, seat & so on. It is attached to the fuselage by 2 solid web aluminum alloy bulkheads, and is boxed in fore & aft by the 2 198 gallon armored fuel tanks. It was designed this way so that later production models would be suitable for pressurization.
IMHO it looks like it would be difficult to get a round into cockpit the from forward or rear areas, and a 90 degree hit from the side at speed would be awful lucky - although I suppose through the canopy can always be assumed.
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EagleDNY
$.02
