Famous Bugs - (nf)

[berry at zinfandel.UUCP]

#R:sri-arpa:-181400:zinfandel:12400027:000:1589
zinfandel!berry    Jun  9 09:13:00 1983

In the April 1980 issue of ACM SIGSOFT Software Engineering Notes,
editor Peter G. Neumann (NEUMANN at SRI-KL at that time) relays information that
Earl Boebert got from Mark Groves (OSD R&E) regarding bugs in
the software of the F-16 fighter.  Apparently a problem in the navigation 
software inverted the aircraft whenever it corssed the equator.  Luckily it
was caught early in simulation testing and promptly fixed.  
  In the July issue, J.N. Frisina at Singer-Kearfott wrote to Mr. Neumann,
"concerned that readers might have mistakenly believed there was a bug in the
flight software, which was of course not the case." [At least they fixed THAT 
one.  Wasn't it Hoare who said that acceptance testing is just an unsuccessful
attempt to find bugs?]  Mr. Frisina wrote:
	"In the current search for reliable software, the F16 Navigation
	software is an example of the high degree of reliability and quality
	that can be obtained with the application of proper design verification
	and testing methodologies.  All primary misison functions were software
	correct."

In the April '81 Issue it is revealed that the F18 range of control travel 
limits imposed by the F18 software are based on assumptions about the 
inability of the aircraft to get into certain attitudes.  Well, some of these
'forbidden' attitudes are in fact attainable.  Apparently so much effort had
gone design and testing of the software that it is now preferable to
modify the aircraft to fit the software, rather than vice-versa!

Berry Kercheval		Zehntel Inc.	(decvax!sytek!zehntel!zinfandel!berry)
(415)932-6900