Date: Thu, 16 Apr 1998 03:05:17 -0700 (PDT)
From: "Rudnicki, Edward J." <erudnick@pica.army.mil>
Subject: RE: Technology in MKC

>  
>> Since most VTOL aircraft use some sort of deflector to "aim"
the engine exhaust downward, it is >not entirely impossible (in the
realm of cartoon physics) for the exhaust from the 2 rear outside
>engines to be diverted back out through the front yellow air intakes.
At the same time VTOL is >engaged, intakes on top of the Turbokat would
provide air for the 3 engines.
>
>We must disagree about redirecting the exhaust.  Not even in
>(reasonable world) cartoon physics world this work unless you
>begin discussing inter-dimensional physics and /or teleportation
>(and that is a whole other discussion I don't mind going into).

>They are just too far apart (at the front of the engines and not
>even near the middle like the Harrier -- I'd love to see a
>diagram of how this could rout exhaust from near the tail to over
>half way up the fuselage).  Take a look at a AV-8B Harrier II
>Plus in action (or even better, a diagram of one) for better
>info.  There's plenty of data out there (book and net) if you
>care that much (including my site on next update).  If I'm wrong,
>point me to the source of new data -- I'd like some of this too
>be true.

Well, one could have ductwork to direct the exhaust forward. We already
know that the internal volume of the TurboKat is substantially greater
than outward appearances would indicate, so what's a few meters of
superalloy exhaust ducting :)

Besides, the front "nozzles" are well-positioned for realism, in that
the front and rear nozzles in VTOL mode provide thrust at roughly equal
distances from the center of mass (the nose and cockpit contributing
relatively little compared to the engines and weapons bay and other
midships items).

And you might want to look at other designs than the Harrier (which is
quite unique), especially the 
Yak-141, which has a rear nozzle much further back than on a Harrier,
and forward lift engines equally far forward of the center of mass. The
Harrier, OTOH, has the nozzle pairs close together because of its unique
and unconventional engine design; the Russian engines are more
conventional.


>> Doesn't the new F-18 have avionics that'll do pretty much the
same thing when a pilot loses >control?
>
>It is the F/A-18 Hornet and as of the last data release I have
>access to, no aircraft has such a system installed.  There are a
>few aircraft (the F-117 Nighthawk primarily) that has a button
>the pilot must press that will position the craft flat, level and
>upright without any other impute, but an auto system does not yet
>exist in practice, and likely never will -- it's too dangerous to
>have your craft suddenly decide to level itself out in the middle
>of a dogfight (katfight?, birdfight? -- do kats actually mention
>a word for this?).

I suspect you're familiar with work not yet complete, on AI systems that
will "fight" the aircraft for brief periods should the pilot black out
from g-loads, until he/she recovers. Not implemented yet, but not very
far over the horizon either. The intent of the system is to monitor the
pilot's vitals and take action only if blackout occurs, so there's not
too much risk of the aircraft making its own decisions when uncalled for




Ed


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