Though not a plane, I think it's a shame that the HeS-30 wasn't allowed to fully develop. It could have been used sucessfully on either the He-280 or the Me 262. The prototype showed thrust of about the same amount as the 004A engine did and weighed about half as much and produced 200lbs more thrust than the 004B. At an airspeed of 500mph the engine was projected to have about 2470 lbs of thrust (coincidentally less than 300 lbs less than the HeS-011 "class II" engine produced in testing)
As stated the engine was much lighter than the other class I engines (only 390kg, 859lb) this lighter construction used far less material than the others and used only a 3-stage compressor. Though more complex in some areas, the resulting problems had been mostly rectified by the time the prototype was ready in May of 1942, only 2 months after the 004A was tested. The engine also utilized conventional flame cans an thus didn't have the same difficulties as the BMW 003, and would have likely been ready for production long before the 003, though probably a few months after the 004.
Unfortunately the German government saw the 004 and 003 as "good enough" (obveously not noticing the problems the 003 was having). They cancelled the HeS-30 along with Heinkel's other class-I engine, the centrifugal HeS-8, in favor of production of the more complex and problematic class II HeS-011 wich had no chance of being ready before the end of the war. This is too bad because 2 HeS-30 engines would have heen as good as any class II engine and would be small enough (2ft in diameter) to be placed side by side or stacked in place of a single, larger class II engine. This arrangement could have been utilized by many of the prototype/experimental aircraft designs without major alteration IMHO.
The Lockheed L-1000 axial turbojet suffered a symilar fate when the USAAF wsa uninterested in funding the twin-engine L-133 jet-fighter project in 1940. Though work the engine was resumed in 1943 and continued later on after the war (as the J37) the design never went beond testbed examples or entered production. The L133 was never developed past scale wind-tunnel models and mock-ups. GE also had a design for a centrifugal turbojet based on one of their turbochargers around the same time but the project never left the drawing board. The main difference between these projects and the German ones like the He-280 is that the Germans continued working on the projects independantly after being denied contrects and eventualy gained the intrest of the government, but sadly, this didn't save Heinkel's project. =(
Too bad Heinkel didn't defect, with his dislike if the Nazi regime's policies (and them in general) and his treatment by them he must have considdered switching sides especialy after his company was "nationalized" in 1942. Though it probably would have been virtualy impossible for someone in his position to escape the axis territory (at least not alive), especialy in that stage of the war.
There were also various other turbojets being designed independently in the US durring the war like the axial-compressor westinghouse turbojets (the J30 which produced 1600lbf and was first operted in fall of '44 and used for the FH Phantom which first flew in early '45 and was basicly the navy's equivalent of the P-59). Check them out, as well as some other early jets, here:
Jets45-Engines
I wonder if the J30s or maby even the J31(if there were enough that had not been diverted to the P59 untill its cancellation and wasn't too much wider than the L-1000) would have worked in the L133 design...
I've seen the beauty of many German engeneered aircraft but of all the early German jet designs I've never seen one that I found as amazing as the L133 (though some were certainly more
unorthadox)
Though the airforce would still probably be uninterested as it was such a radical design. Still it would be cool to see a flight sim feature it, same for the He-280.