Question about the F-22 and it's radar.

So the processors are obsolete, (too old)... the Avionic architecture
needs to be replaced before the F-22 can become the F/A-22 because the
present system is based on the old processors and rewriting the code
is pointless on an obsolete system, that would only support half of
the F-22 fleet

Methinks there's some confusion there between processors, avionics
architecture, and software.
While it's true that Intel tried to shut down i960 production causing a
chinese fire drill, there are enough assets to get by until a new processor is
ready. That has nothing to do with the avionics architecture, which is
not changing. Plus the whole point of writing all the OS and AS in Ada was
to be as platform independent as possible, so that upgrades to the CIP
could be relatively painless and not force re-flight testing of the A/C.
Ideally, one would not re-write the code, but re-compile the code for
the new platform, then do a LOT of integrity checks, and take it from there...


The question is does this 'new' processor conform to the 3 F's, Form
Fit and Function?, If not then the processor demands a new
architecture to support it, with the new architecture comes the the
burden of porting it over, couple that with the reliability problems
now being experienced and you have a flakey system thats being ported.

AFAIK there is no 3F for the i960, therefor the system has quite
neatly side stepped the reletivly painless CIP upgrade path.

The F-22 is under enormous pressure to perform right now, with the
review reporting back in the next few months, any talk of obsolete
systems in the state of the art jet are being downplayed.

They have to go with a more COTS based system (similar to, if not the
same as the JSF), which they are working on now, for fielding in (very
optomisticlly) in 2007.

Other than using commercialy available processor chips, what is "COTS"
about it?
Hint - nothing.

Other than the Raptors costs its the cheapest fighter in the world...
seriously the F-22 team will be levering the development work on the
JSF for all its worth, anything to shove costs away from the f-22
program.

What is the new processor? I always thought that a federated system
had certain advantages with regard to upgradeing.


Other facts (what a concept in RAM)
The F-22 is also based on commercialy available processor chips (but
not a commercial architecture)
Avionics systems require a much higher level of security and determinism
than any "COTS" package will ever offer.
COTS is not necessarily cheaper when talking avionics

COTS is one of those words that everyone thinks they understand, until
it comes down to brass tacks.


A simple analogy for you, the old 486 computer still works, but when I
wanted to run XP on it the demands of the system increased to the
point where it was useless to try, and you couldn't buy a 486
processor anywhere to support it.

I call that an 'obsolete system', it worked great running win 98.

Your analogy is seriously flawed for several reasons:
A processor does not stand alone, it's part of a system, and many,
many other things affect the system performance besides processor
speed. Backside bus bandwidth, memory architecture, frontside bus
bandwidth, etc.
Plus the system in this case contains MANY processors in parallel.
The system is officially termed a heterogeneous multi-processing system
which means that it has several different kinds of processors as well
as the i960, and all running in parallel. I think someone calculated
the actual processing resources are equal to 2 Cray Y-MP supercomputers.
Software also matters. Comparing avionics software to microS's
bloatware is ludicrous.

It was a simple analogy, not designed to compare avionics and M$ code,
but to show why an upgrade is required, if it can't hack the
requirements it needs upgrading, its that simple, If it can hack it,
no upgrade is required - simple as that.



Now the Raptor can't run the software to do its air to ground mission
for the same reasons what would you call it?. "processor
challenged???"

I'd say, take a hard look at the above assertation and explain how it
can be true, given that other AESA radars, in service, and with smaller
avionics processors, don't seem to be having these problems.

Take it up with the USAF, their requirements call for a certain level
of capability in the AtoG role, the F-22 currently does not have the
software or the hardware to fullfill that capability - hence the need
for upgrades, what other reason is there for an upgrade...?.



BTW, I worked on AFT, F-22, and several other current AESA programs,
including airborne processors, and integrated avionics systems.


Great, here' s a couple of questions for you.
Do you think they will combine the AESA antennas for the JSF and the
F-22 to a common 1200 module system? (I saw the number of modules for
the F-22 was at 1500). I had heard a rumour that this was on the
cards for cost savings etc.

Why is the Raptors Software so troubled?.

Cheers


John Cook

Any spelling mistakes/grammatic errors are there purely to annoy. All
opinions are mine, not TAFE's however much they beg me for them.

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