F-22 Raptor software problem

F-22 Raptor software problem

[Hyman Rosen]

It's being reported (Slashdot, via CNN) that twelve of these
planes had their navigation and communications completely shut
down as they crossed the international date line while flying
from Hawaii to Japan. I believe much of the plane's software
is in Ada, but I have no details as to what caused the error.

Re: F-22 Raptor software problem

[Alex R. Mosteo]

Hyman Rosen wrote:

> It's being reported (Slashdot, via CNN) that twelve of these
> planes had their navigation and communications completely shut
> down as they crossed the international date line while flying
> from Hawaii to Japan. I believe much of the plane's software
> is in Ada, but I have no details as to what caused the error.

Linky to slashdot:

http://it.slashdot.org/article.pl?sid=07/02/25/2038217

"The new US stealth fighter, the F-22 Raptor, was deployed for the first time
to Asia earlier this month. On Feb. 11, twelve Raptors flying from Hawaii to
Japan were forced to turn back when a software glitch crashed all of the
F-22s' on-board computers as they crossed the international date line. The
delay in arrival in Japan was previously reported, with rumors of problems
with the software. CNN television, however, this morning reported that every
fighter completely lost all navigation and communications when they crossed
the international date line. They reportedly had to turn around and follow
their tankers by visual contact back to Hawaii. According to the CNN story, if
they had not been with their tankers, or the weather had been bad, this would
have been serious. CNN has not put up anything on their website yet."

The summary is, they say in the comments, incorrect, since the F22 relies in
computers for control so a crash of "all on-board computers" would have been
quite a bigger problem.

Re: F-22 Raptor software problem

[Aurele]

On Feb 26, 3:55 am, "Alex R. Mosteo" <devn...@mailinator.com> wrote:
> Hyman Rosen wrote:
> > It's being reported (Slashdot, via CNN) that twelve of these
> > planes had their navigation and communications completely shut
> > down as they crossed the international date line while flying
> > from Hawaii to Japan. I believe much of the plane's software
> > is in Ada, but I have no details as to what caused the error.
>
> Linky to slashdot:
>
> http://it.slashdot.org/article.pl?sid=07/02/25/2038217
>
> "The new US stealth fighter, the F-22 Raptor, was deployed for the first time
> to Asia earlier this month. On Feb. 11, twelve Raptors flying from Hawaii to
> Japan were forced to turn back when a software glitch crashed all of the
> F-22s' on-board computers as they crossed the international date line. The
> delay in arrival in Japan was previously reported, with rumors of problems
> with the software. CNN television, however, this morning reported that every
> fighter completely lost all navigation and communications when they crossed
> the international date line. They reportedly had to turn around and follow
> their tankers by visual contact back to Hawaii. According to the CNN story, if
> they had not been with their tankers, or the weather had been bad, this would
> have been serious. CNN has not put up anything on their website yet."
>
> The summary is, they say in the comments, incorrect, since the F22 relies in
> computers for control so a crash of "all on-board computers" would have been
> quite a bigger problem.

Well, someone is likely to lose their job for improperly implementing
the geoid and/or datum model!

Re: F-22 Raptor software problem

[Simon Wright]

"Aurele" <aurele.vitali@gmail.com> writes:

> Well, someone is likely to lose their job for improperly
> implementing the geoid and/or datum model!

Or perhaps for not ensuring that the test cases covered this
possibility. I have to say I'm not sure I would have thought of that
one!

Re: F-22 Raptor software problem

[JPWoodruff]

On Feb 26, 7:01 am, "Aurele" <aurele.vit...@gmail.com> wrote:
> On Feb 26, 3:55 am, "Alex R. Mosteo" <devn...@mailinator.com> wrote:
>
>
>
> > Hyman Rosen wrote:
> > > It's being reported (Slashdot, via CNN) that twelve of these
> > > planes had their navigation and communications completely shut
> > > down as they crossed the international date line while flying
> > > from Hawaii to Japan. I believe much of the plane's software
> > > is in Ada, but I have no details as to what caused the error.
>
> > Linky to slashdot:
>
> >http://it.slashdot.org/article.pl?sid=07/02/25/2038217
>
> > "The new US stealth fighter, the F-22 Raptor, was deployed for the first time
> > to Asia earlier this month. On Feb. 11, twelve Raptors flying from Hawaii to
> > Japan were forced to turn back when a software glitch crashed all of the
> > F-22s' on-board computers as they crossed the international date line. The
> > delay in arrival in Japan was previously reported, with rumors of problems
> > with the software. CNN television, however, this morning reported that every
> > fighter completely lost all navigation and communications when they crossed
> > the international date line. They reportedly had to turn around and follow
> > their tankers by visual contact back to Hawaii. According to the CNN story, if
> > they had not been with their tankers, or the weather had been bad, this would
> > have been serious. CNN has not put up anything on their website yet."
>
> > The summary is, they say in the comments, incorrect, since the F22 relies in
> > computers for control so a crash of "all on-board computers" would have been
> > quite a bigger problem.
>
> Well, someone is likely to lose their job for improperly implementing
> the geoid and/or datum model!


I don't think fault will fall so harshly on the implementer.  But the
members of the configuration control committee have some explaining to
do.

Re: F-22 Raptor software problem

[peter koch]

On 26 Feb., 05:47, Hyman Rosen <hyro...@mail.com> wrote:
> It's being reported (Slashdot, via CNN) that twelve of these
> planes had their navigation and communications completely shut
> down as they crossed the international date line while flying
> from Hawaii to Japan. I believe much of the plane's software
> is in Ada, but I have no details as to what caused the error.

It surprises me that the software had problems dealing with this
problem in the first place. Why anyone uses "calender time" for
anything but display purposes is simply beyond my comprehension.

/Peter

Re: F-22 Raptor software problem

[Jeffrey Creem]

Aurele wrote:

> Well, someone is likely to lose their job for improperly implementing
> the geoid and/or datum model!
> 

Given the age of the F-22 software, the person that wrote it is probably 
retired by now. Either way, people rarely loose their jobs for such things.

Re: F-22 Raptor software problem

[Gene]

On Feb 26, 6:55 pm, "peter koch" <peter.koch.lar...@gmail.com> wrote:
> On 26 Feb., 05:47, Hyman Rosen <hyro...@mail.com> wrote:
>
> > It's being reported (Slashdot, via CNN) that twelve of these
> > planes had their navigation and communications completely shut
> > down as they crossed the international date line while flying
> > from Hawaii to Japan. I believe much of the plane's software
> > is in Ada, but I have no details as to what caused the error.
>
> It surprises me that the software had problems dealing with this
> problem in the first place. Why anyone uses "calender time" for
> anything but display purposes is simply beyond my comprehension.
>
> /Peter

I vaguely remember years ago reading that the original F-16 flight
control software flipped the plane inverted when flown into the
southern hemisphere.  However, this was caught in a simulator before
the software was ever flown.  History repeats itself (sort of...).

Re: F-22 Raptor software problem

[Bob Spooner]

"Aurele" <aurele.vitali@gmail.com> wrote in message 
news:1172502110.098416.297700@q2g2000cwa.googlegroups.com...
> On Feb 26, 3:55 am, "Alex R. Mosteo" <devn...@mailinator.com> wrote:
>
> Well, someone is likely to lose their job for improperly implementing
> the geoid and/or datum model!
>
I would be inclined to think that the (derived) requirements were 
incompletely specified and therefore didn't cover the case of what happens 
when the nav system, while using GPS signals for time, crosses the date line 
(or something like that.)  -- Bob 

Re: F-22 Raptor software problem

[Aurele]

On Feb 27, 9:33 am, "Bob Spooner" <r...@psu.edu> wrote:
> "Aurele" <aurele.vit...@gmail.com> wrote in message
>
> news:1172502110.098416.297700@q2g2000cwa.googlegroups.com...> On Feb 26, 3:55 am, "Alex R. Mosteo" <devn...@mailinator.com> wrote:
>
> > Well, someone is likely to lose their job for improperly implementing
> > the geoid and/or datum model!
>
> I would be inclined to think that the (derived) requirements were
> incompletely specified and therefore didn't cover the case of what happens
> when the nav system, while using GPS signals for time, crosses the date line
> (or something like that.)  -- Bob

I'm sure its not a drived requirement. The international date line has
been there forever! Also, time is always measured wrt Greenwich time
in England. So, not a big deal. As Simon above said, it is probably
just a test case that fell through the cracks!  Go to
http://wwp.greenwichmeantime.com/info/timezone.htm for more info on
Time Zones.

p.s. "or something like that" has very little meaning! :-)

Re: F-22 Raptor software problem

[JPWoodruff]

On Feb 27, 6:33 am, "Bob Spooner" <r...@psu.edu> wrote:
> "Aurele" <aurele.vit...@gmail.com> wrote in message
>
> news:1172502110.098416.297700@q2g2000cwa.googlegroups.com...> On Feb 26, 3:55 am, "Alex R. Mosteo" <devn...@mailinator.com> wrote:
>
> > Well, someone is likely to lose their job for improperly implementing
> > the geoid and/or datum model!
>
> I would be inclined to think that the (derived) requirements were
> incompletely specified and therefore didn't cover the case of what happens
> when the nav system, while using GPS signals for time, crosses the date line
> (or something like that.)  -- Bob


Something's bothering me about this case, and hasn't been mentioned
yet.

I think I'm correct in guessing that this aircraft has been in service
for some time. If that's true, then almost certainly some F-22 has
crossed the dateline without difficulty in the past. So it's a change
in the software that started the failure.

My own experience taught me it's difficult to assure integrity as a
large system evolves. The system needs an effective configuration
control board, and that team needs a really sound process.  This is
easier said than done.   We can hope that practical "lessons learned"
will be shared when this case has been analyzed.

Re: F-22 Raptor software problem

[Keith Thompson]

"peter koch" <peter.koch.larsen@gmail.com> writes:
> On 26 Feb., 05:47, Hyman Rosen <hyro...@mail.com> wrote:
>> It's being reported (Slashdot, via CNN) that twelve of these
>> planes had their navigation and communications completely shut
>> down as they crossed the international date line while flying
>> from Hawaii to Japan. I believe much of the plane's software
>> is in Ada, but I have no details as to what caused the error.
>
> It surprises me that the software had problems dealing with this
> problem in the first place. Why anyone uses "calender time" for
> anything but display purposes is simply beyond my comprehension.

I'm only guessing, but I doubt that the error was caused by using
local time.  My suspicion is that the error occurred not when crossing
the International Date Line (which is crooked, as you can see on a
map), but when crossing the 180th meridian, when the longitude jumped
from 179.909 to -179.990.

I vaguely remember a similar problem with some air traffic control
software that was developed in the US, but wouldn't work in the UK,
because it couldn't handle a sign change in longitude.

-- 
Keith Thompson (The_Other_Keith) kst-u@mib.org  <http://www.ghoti.net/~kst>
San Diego Supercomputer Center             <*>  <http://users.sdsc.edu/~kst>
"We must do something.  This is something.  Therefore, we must do this."
-- Antony Jay and Jonathan Lynn, "Yes Minister"

Re: F-22 Raptor software problem

[peter koch]

On Feb 28, 8:44 am, Keith Thompson <k...@mib.org> wrote:
> "peter koch" <peter.koch.lar...@gmail.com> writes:
> > On 26 Feb., 05:47, Hyman Rosen <hyro...@mail.com> wrote:
> >> It's being reported (Slashdot, via CNN) that twelve of these
> >> planes had their navigation and communications completely shut
> >> down as they crossed the international date line while flying
> >> from Hawaii to Japan. I believe much of the plane's software
> >> is in Ada, but I have no details as to what caused the error.
>
> > It surprises me that the software had problems dealing with this
> > problem in the first place. Why anyone uses "calender time" for
> > anything but display purposes is simply beyond my comprehension.
>
> I'm only guessing, but I doubt that the error was caused by using
> local time.  My suspicion is that the error occurred not when crossing
> the International Date Line (which is crooked, as you can see on a
> map), but when crossing the 180th meridian, when the longitude jumped
> from 179.909 to -179.990.
>
> I vaguely remember a similar problem with some air traffic control
> software that was developed in the US, but wouldn't work in the UK,
> because it couldn't handle a sign change in longitude.
>
Yes - that makes far more sense. I had a very difficult time (!)
believe that the problem had anything to do with timezones.

/Peter

Re: F-22 Raptor software problem

[Bob Spooner]

"Aurele" <aurele.vitali@gmail.com> wrote in message 
news:1172635528.435013.151190@m58g2000cwm.googlegroups.com...
> On Feb 27, 9:33 am, "Bob Spooner" <r...@psu.edu> wrote:
>> "Aurele" <aurele.vit...@gmail.com> wrote in message
>>
>> news:1172502110.098416.297700@q2g2000cwa.googlegroups.com...> On Feb 26, 
>> 3:55 am, "Alex R. Mosteo" <devn...@mailinator.com> wrote:
>>
>> > Well, someone is likely to lose their job for improperly implementing
>> > the geoid and/or datum model!
>>
>> I would be inclined to think that the (derived) requirements were
>> incompletely specified and therefore didn't cover the case of what 
>> happens
>> when the nav system, while using GPS signals for time, crosses the date 
>> line
>> (or something like that.)  -- Bob
>
> I'm sure its not a drived requirement. The international date line has
> been there forever! Also, time is always measured wrt Greenwich time
> in England. So, not a big deal. As Simon above said, it is probably
> just a test case that fell through the cracks!  Go to
> http://wwp.greenwichmeantime.com/info/timezone.htm for more info on
> Time Zones.
>
> p.s. "or something like that" has very little meaning! :-)
>
Well, the reason I think that it is a derived requirement is because if it 
were explicit in the contract, there would have to be traceability to both 
the code implementation and to the test that verified that it was 
implemented correctly.  Bob 

Re: F-22 Raptor software problem

[Bob Spooner]

"peter koch" <peter.koch.larsen@gmail.com> wrote in message 
news:1172666017.141406.173400@v33g2000cwv.googlegroups.com...
> On Feb 28, 8:44 am, Keith Thompson <k...@mib.org> wrote:
>> "peter koch" <peter.koch.lar...@gmail.com> writes:
>> > On 26 Feb., 05:47, Hyman Rosen <hyro...@mail.com> wrote:
>> >> It's being reported (Slashdot, via CNN) that twelve of these
>> >> planes had their navigation and communications completely shut
>> >> down as they crossed the international date line while flying
>> >> from Hawaii to Japan. I believe much of the plane's software
>> >> is in Ada, but I have no details as to what caused the error.
>>
>> > It surprises me that the software had problems dealing with this
>> > problem in the first place. Why anyone uses "calender time" for
>> > anything but display purposes is simply beyond my comprehension.
>>
>> I'm only guessing, but I doubt that the error was caused by using
>> local time.  My suspicion is that the error occurred not when crossing
>> the International Date Line (which is crooked, as you can see on a
>> map), but when crossing the 180th meridian, when the longitude jumped
>> from 179.909 to -179.990.
>>
>> I vaguely remember a similar problem with some air traffic control
>> software that was developed in the US, but wouldn't work in the UK,
>> because it couldn't handle a sign change in longitude.
>>
> Yes - that makes far more sense. I had a very difficult time (!)
> believe that the problem had anything to do with timezones.
>
> /Peter
>
If the navigation computer was calculating velocity as a change in position 
with respect to time and the time changed by a large (possibly negative) 
amount, something could have gotten out of range and caused a software 
crash.  Bob 

Re: F-22 Raptor software problem

[Markus E Leypold]

"Bob Spooner" <rls19@psu.edu> writes:

> "peter koch" <peter.koch.larsen@gmail.com> wrote in message 
> news:1172666017.141406.173400@v33g2000cwv.googlegroups.com...
>> On Feb 28, 8:44 am, Keith Thompson <k...@mib.org> wrote:
>>> "peter koch" <peter.koch.lar...@gmail.com> writes:
>>> > On 26 Feb., 05:47, Hyman Rosen <hyro...@mail.com> wrote:
>>> >> It's being reported (Slashdot, via CNN) that twelve of these
>>> >> planes had their navigation and communications completely shut
>>> >> down as they crossed the international date line while flying
>>> >> from Hawaii to Japan. I believe much of the plane's software
>>> >> is in Ada, but I have no details as to what caused the error.
>>>
>>> > It surprises me that the software had problems dealing with this
>>> > problem in the first place. Why anyone uses "calender time" for
>>> > anything but display purposes is simply beyond my comprehension.
>>>
>>> I'm only guessing, but I doubt that the error was caused by using
>>> local time.  My suspicion is that the error occurred not when crossing
>>> the International Date Line (which is crooked, as you can see on a
>>> map), but when crossing the 180th meridian, when the longitude jumped
>>> from 179.909 to -179.990.
>>>
>>> I vaguely remember a similar problem with some air traffic control
>>> software that was developed in the US, but wouldn't work in the UK,
>>> because it couldn't handle a sign change in longitude.
>>>
>> Yes - that makes far more sense. I had a very difficult time (!)
>> believe that the problem had anything to do with timezones.
>>
>> /Peter
>>
> If the navigation computer was calculating velocity as a change in position 
> with respect to time and the time changed by a large (possibly negative) 
> amount, something could have gotten out of range and caused a software 
> crash.  Bob 


On would think that internal time keeping would always done in GMT or
with a counter with a fixed offset to GMT, esp. since GPS works with
GMT anyway.

Regards -- Markus

Re: F-22 Raptor software problem

[Simon Wright]

"peter koch" <peter.koch.larsen@gmail.com> writes:
> On Feb 28, 8:44 am, Keith Thompson <k...@mib.org> wrote:

>> I'm only guessing, but I doubt that the error was caused by using
>> local time.  My suspicion is that the error occurred not when
>> crossing the International Date Line (which is crooked, as you can
>> see on a map), but when crossing the 180th meridian, when the
>> longitude jumped from 179.909 to -179.990.

> Yes - that makes far more sense. I had a very difficult time (!)
> believe that the problem had anything to do with timezones.

I could believe it if there were requirements to do something say
every quarter-hour on the quarter-hour in local time. What seems hard
to imagine in a military aircraft is the 'local time' part!

Re: F-22 Raptor software problem

[Keith Thompson]

Keith Thompson <kst-u@mib.org> writes:
[...]
> I'm only guessing, but I doubt that the error was caused by using
> local time.  My suspicion is that the error occurred not when crossing
> the International Date Line (which is crooked, as you can see on a
> map), but when crossing the 180th meridian, when the longitude jumped
> from 179.909 to -179.990.

Sorry about the random-seeming numbers.  I meant "from 179.999 to
-179.999".  (I originally used two decimal places, then decided to add
a third, and typed '0' instead of '9'.)

I *will* proofread this before sending it!

-- 
Keith Thompson (The_Other_Keith) kst-u@mib.org  <http://www.ghoti.net/~kst>
San Diego Supercomputer Center             <*>  <http://users.sdsc.edu/~kst>
"We must do something.  This is something.  Therefore, we must do this."
    -- Antony Jay and Jonathan Lynn, "Yes Minister"

Re: F-22 Raptor software problem

[Keith Thompson]

Simon Wright <simon.j.wright@mac.com> writes:
> "peter koch" <peter.koch.larsen@gmail.com> writes:
>> On Feb 28, 8:44 am, Keith Thompson <k...@mib.org> wrote:
>>> I'm only guessing, but I doubt that the error was caused by using
>>> local time.  My suspicion is that the error occurred not when
>>> crossing the International Date Line (which is crooked, as you can
>>> see on a map), but when crossing the 180th meridian, when the
>>> longitude jumped from 179.909 to -179.990.
>
>> Yes - that makes far more sense. I had a very difficult time (!)
>> believe that the problem had anything to do with timezones.
>
> I could believe it if there were requirements to do something say
> every quarter-hour on the quarter-hour in local time. What seems hard
> to imagine in a military aircraft is the 'local time' part!

It would be easier to do something every quarter-hour in UTC; it will
be done at the sames, even in places with half-hour time zones.  And
an F-22 at top speed can cross a time zone in a few minutes.
Performing tasks that depend on local time wouldn't make much sense;
performing such tasks in a critical subsystem (which is what crashed)
makes even less sense.

-- 
Keith Thompson (The_Other_Keith) kst-u@mib.org  <http://www.ghoti.net/~kst>
San Diego Supercomputer Center             <*>  <http://users.sdsc.edu/~kst>
"We must do something.  This is something.  Therefore, we must do this."
    -- Antony Jay and Jonathan Lynn, "Yes Minister"