Eurofighter technical problems.

Alisha's Addict wrote in message . ..
On Tue, 25 May 2004 22:22:43 +0100, "Ian"
wrote:


"Eric Moore" wrote in message
m...
It looks like the F-22 isn't the only aircraft with teething problems.
See:

http://www.spacewar.com/2004/040524222142.i5vufze7.html

Anyone care to speculate on how long it will take de-bug this aircraft?
SNIP:
Dump Windows XXX and go to Linux? Who knows, but at least no more
screen of blue death.
Walt BJ

In article ,
(Prowlus) writes:
Alisha's Addict wrote in message . ..
On Tue, 25 May 2004 22:22:43 +0100, "Ian"
wrote:




More news from The Register :
http://www.theregister.co.uk/2004/05/25/mod_leak/

Pete Lilleyman

(please get rid of ".getrid" to reply direct)
(don't get rid of the dontspam though ;-)

wouldn't "corruption" mean a faulty hard drive/memory unit that just
needs to be replaced? Surely that could be done a small amount of time
although can't see the point of the RAF cranking out so many
two-seater Tffies for training purposes. whats the point of buying the
advanced version of the Hawk then if their wasting money on pricey
trainer version of the typhoon?

It's unlikely to be a hard drive. (There shouldn't be one at all, for
a system like that)
Corruption, in the Real TIme System context, such as a Flight Centrol
System, ir Data Acq, or other such, menas that the program is stomping
all over its volatile data. In other words, the airplane doesn't know
where it it, what it has done, or what it's doing now. If you know teh
systems, and can read teh clues, it can be even worse than that. Many
real time systems copy their inital programs & state from non-volatile
storage (Prom, Eprom, or EEprom, or possibly Flash) to RAM to actually
run. (Far better access times with RAM). in that case, it's entire
possible for the system to stomp all over the running program, as
well. (Fandango on Core) wiping all of teh current state out.
Having this happen in flight would be Very, Very, Very Bad.

--
Pete Stickney
A strong conviction that something must be done is the parent of many
bad measures. -- Daniel Webster

"Paul F Austin" wrote in message
...

"Ian" wrote in message
...

"Eric Moore" wrote in message
...
It looks like the F-22 isn't the only aircraft with teething problems.
See:

http://www.spacewar.com/2004/040524222142.i5vufze7.html

Anyone care to speculate on how long it will take de-bug this
aircraft?

Can't get the URL to work properly on my machine, but if its the report
I
think it is, a lot of the issues have either gone away (were just
arguing
over the phrases some release documents used) or are only as a result of
the
so called independent assessors (who were funded by the MoD!!!) not
really
liking the UK prime company. Funny how all four partner countries have
the
same flight control software, yet only the UK are "unhappy" If they're
that
unhappy with it, how come a pair of the RAF jets have just flown over my
house??

That may be the case for most of the bugs cited by QinetiQ but some are
serious:

"Corruption" of the flight control computer system means that it could
suddenly switch from "in-flight" mode to "ground" mode in mid-air, leading
to "immediately catastrophic" results.

and

The cockpit flight information displays "frequently fail in flight", and
therefore, whenever a Eurofighter is taken into cloud or bad weather, it
should again be with two pilots.

sound quite serious, although I don't know how a second pilot will help in
the second case.

The corruption of the FCC was never a real issue - it was more to do with
the way the testing was reported. Funny thing is, the tests that were
performed were to a QinetiQ spec. Funnily enough the spec was never
questioned by anybody outside BAe who had concerns that it wasn't the right
thing. As far as I know the "frequent" cockpit display failures means two
in a development fleet just over 10 years old. Suppose 1 every five years is
frequent! Hasn't stopped them flying the things from Warton where its
normally cloudy (although havent seen that many clouds over teh last few
weeks!)

On Tue, 25 May 2004 23:01:01 -0400, (Peter
Stickney) wrote:
snip
wouldn't "corruption" mean a faulty hard drive/memory unit that just
needs to be replaced? Surely that could be done a small amount of time
although can't see the point of the RAF cranking out so many
two-seater Tffies for training purposes. whats the point of buying the
advanced version of the Hawk then if their wasting money on pricey
trainer version of the typhoon?

It's unlikely to be a hard drive. (There shouldn't be one at all, for
a system like that)
Corruption, in the Real TIme System context, such as a Flight Centrol
System, ir Data Acq, or other such, menas that the program is stomping
all over its volatile data. In other words, the airplane doesn't know
where it it, what it has done, or what it's doing now. If you know teh
systems, and can read teh clues, it can be even worse than that. Many
real time systems copy their inital programs & state from non-volatile
storage (Prom, Eprom, or EEprom, or possibly Flash) to RAM to actually
run. (Far better access times with RAM). in that case, it's entire
possible for the system to stomp all over the running program, as
well. (Fandango on Core) wiping all of teh current state out.
Having this happen in flight would be Very, Very, Very Bad.

Heres a portion of the executive summary:-

"1.4 Landing Gear Computer

1.4.1 At least twelve failures of the Landing Gear Computer (LGC) have
occured since it was productionised for Series Production Aircraft.
Although modifications to the LGC were introduced following initial
failures, a number of subsequent failures have occurred. These
failures have been unpredictable, and have caused incidents whereby
aircraft have had invalid Landing Gear indication and/or loss of
braking. Recommendations to reduce the impact of invalid Landing Gear
indication and loss of braking have been provided.

1.4.2 It is believed by industry that the problems lie with Electronic
Programmable Logic Devices (EPLDs) inside the LGC; however, the causes
of the failure are not fully understood. Multiple failures of these
ELPDs may cause a corruption of the Nose, and the Left or Right Weight
on Wheels (WoW) Solid State Relays (SSR). There remains an
unquantified risk that the SSRs’ corruption could result in a change
in Flight Control System status from FLIGHT to GROUND, which would be
immediately catastrophic. There is no feasible practical mitigation
for such an event, making it UNACCEPTABLE.

1.4.3 It is therefore recommended as ESSENTIAL that the LGC failure
modes are investigated, understood, and, if necessary, rectified
before release to service. "

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.

Email Address :-
Spam trap - please remove (trousers) to email me
Eurofighter Website :- http://www.eurofighter-typhoon.co.uk

On Tue, 25 May 2004 17:38:41 -0400, Paul F Austin wrote:

That may be the case for most of the bugs cited by QinetiQ but some are
serious:

"Corruption" of the flight control computer system means that it could
suddenly switch from "in-flight" mode to "ground" mode in mid-air, leading
to "immediately catastrophic" results.

and

The cockpit flight information displays "frequently fail in flight", and
therefore, whenever a Eurofighter is taken into cloud or bad weather, it
should again be with two pilots.

sound quite serious, although I don't know how a second pilot will help in
the second case.

The impression I get is that the fault is a software bug rather than
hardware corruption. It's not as if they're using a dodgy cheapo
hard disk to store it on!

--
"It's easier to find people online who openly support the KKK than
people who openly support the RIAA" -- comment on Wikipedia
(Email: zen19725 at zen dot co dot uk)

"phil hunt" wrote in message
rg...
On Tue, 25 May 2004 17:38:41 -0400, Paul F Austin
wrote:

That may be the case for most of the bugs cited by QinetiQ but some are
serious:

"Corruption" of the flight control computer system means that it could
suddenly switch from "in-flight" mode to "ground" mode in mid-air,
leading
to "immediately catastrophic" results.

and

The cockpit flight information displays "frequently fail in flight", and
therefore, whenever a Eurofighter is taken into cloud or bad weather, it
should again be with two pilots.

sound quite serious, although I don't know how a second pilot will help
in
the second case.

The impression I get is that the fault is a software bug rather than
hardware corruption. It's not as if they're using a dodgy cheapo
hard disk to store it on!

I agree. I have the same impression. If the FCS goes TU in an aircraft
that's statically unstable in pitch for instance, the results would be
"immediately catastrophic"