Limes

You've got some good ideas, but I'm not sure they should necessarily be adopted either. Two reasons - firstly I think adding specific precooler parts etc is too complex for your average user. We don't have separate fuel pump or ullage motor parts to go with our liquid rocket fuel tanks, they're assumed to be included in the tank. Similarly, I think precoolers can be assumed to be included in the intake part. I do like your temperature limits idea though - perhaps the intake could overheat at a given speed/density combination, with different intakes having different limits (the ram air intake part can withstand higher speeds, but with a cost of higher weight, for example). Secondly, the whole point of adding separate "intake" parts is to try to give the user some engineering control over how the engines perform at the "edge of the envelope". If you were designing a jet engine for a planet/moon with a thin atmosphere such as Laythe, one of the things you'd do would be give it large air intake area to allow it to cope with the thin atmosphere, and the current system allows this. Setting hard altitude/density limits is too restrictive, and if you're going to do that it begs the question as to why the air intake is a separate part at all. I do, however, like the idea about keeping track of the maximum air required. If you have too much intake area for your engines, there should perhaps be large drag penalties.

Four easy(ish) ideas to reduce intake abuse: - Remove the ability of most parts to transmit the "IntakeAir" fuel. Having parts such as small cubic struts be able to act as a fuel crossfeed for intake air is ridiculous. Restricting it to just jet fuel tanks, those bi/tri/quad coupler parts, and possibly a few others (e.g. the inline docking port) should remove the ability of people to mount air intakes on wings, in long "barrels", or in front of rocket motors (that are away from jet engines). They should really only work if they're mounted directly in front of the jets themselves. - Increase the weight of the intakes to an appreciable fraction of the engines themselves. This idea was discussed above. - Give intakes a maximum operating speed. If your craft is covered in re-entry flames, air intakes ought not to work. - Greatly increase the drag of intakes. If you've got an enormous flat surface of 20 intakes on your craft, a single turbojet ought not to have enough oomph to propel what is essentially an enormous barn door into space from low altitudes. What do people think? I'm not a fan of simply reducing the number of intakes allowed per engine, as it seems rather arbitrary and unphysical. If you want to slap a ridiculous number of intakes onto some mushrooming array of bi/tri/quad couplers in front of your engine, you should be allowed to do so - HOWEVER, your design should have to cope with some slightly more realistic engineering challenges of doing so. You shouldn't *want* to design the style of intake abuse craft we see in current versions, because it shouldn't be an *efficient* way of doing things. For example, there's nothing stopping you slapping 20 orange fuel tanks on top of a rockomax poodle engine, but nobody does it because it's a stupid way to design a craft.