Tuesday, March 17, 2009

Preemptive Fire Suppression

Someone just sent me this link to a story with pictures about what happened to a United Airlines Boeing 767 that had just been refurbished with an all new interior and passenger entertainment system. It was sitting in the maintenance hangar in Chicago, almost ready to be released back to the line, when the hangar fire suppression system activated. It was the third erroneous activation of the system in as many weeks.

Now a hangar full of airplanes needs some serious firefighting capability. An airplane pulled in off the line with a problem may have thousands of pounds of jet fuel inside it, and a fire could kill dozens of workers. So this is not a sprinkler like the one in your office. This is an automatic deluge of thousand p.s.i. water cannons, blowing through eleven side windows and destroying the new interior, and the entertainment system. The list of resulting maintenance issues at the bottom of the page shows that the cockpit was also drenched, with radios and numerous avionics destroyed, including multiple computer display screens. Everything will need to be removed and cleaned, and a lot replaced, and likely the airplane will suffer from irritating avionics problems for years to come.

Word is that the fire system contract went to the lowest bidder.

4 comments:

jinksto said...

Well... it didn't burn, now did it? It's funny but I hate to see any airplane damaged like that.

It's sad seeing that much go to waste while I'm browsing AeroTrader wishing I could afford even an ultralight. hmmm... I wonder how much they want for it now.

zb said...

Reminds me of a former boss who wanted to put something into an electronic device that would make it break in a safe manner in a case a certain error condition was detected. The problem was that this 'something' was not only dirt cheap, it was also much more prone to failure than the original circuit, thus the whole thing blew quite often and we got plenty of blown units back from customers... I had been thinking about quitting working for him for a while already, I knew I had to when this was going on.

Even international standards for safety of machinery like ISO 13849-1 say that a protective device must not cause more failures than it prevents.

Anonymous said...

Really, any engineer or manager who needs to read 13849-1 to know that safety systems shouldn't increase the catastrophic failure rate shouldn't be put in charge of anything more complex than a dog house.

There are lots of PEs out there who shouldn't be put in charge of anything more complex than a dog house....

zb said...

Anon, he wasn't a PE, he was the boss of the whole darn company. Happens when you start in a garage with 2 friends and never accept the fact that 25 years down the road, with more than 500 employees, you have to slightly adjust the rules...