Re: More 737 problems?

Date:         30 Nov 98 03:08:02 
From:         kls@ohare.Chicago.COM (Karl Swartz)
Organization: Chicago Software Works, Menlo Park, California
References:   1 2 3 4
View raw article
  or MIME structure

>>At best or at worst?  The 500+ people who were killed when the aft
>>bulkhead on a certain 747 failed illustrate the worst case.

> Any chance this could have been a factor in Colorado Springs or
>US427?  I know they were both relatively low, but transition to/from
>pressurized altitude causes stresses, correct?  If a failure had
>occurred in the bulkhead could it have impacted primary control
>movement cables, hydraulics, etc. during transition?

There are undoubtedly stresses during depressurization, but without the
pressure differential you're not likely to have a spectacular failure.
JL 123 (the 747 I referred to) was at FL240 when it's aft pressure
bulkhead failed.  The large volume of air suddenly vented into the APU
compartment and vertical tail literally blew the aft end of the plane
apart -- a fuzzy photograph taken from the ground reveals only the
barest hints of a vertical tail.  Even at that, it managed to stay in
the air for over 32 minutes.

In contrast, UA 585 (Colorado Springs) was at about 1100 feet AGL.  At
that altitude, the pressure differential wouldn't have produced enough
pressure to do much other than show up on some gauges.  US 427 was at
about 6000 feet, but that's still not a huge pressure difference.  In
both accidents, they splattered in less than 30 seconds.

In any case, even if there hadn't been parts found some distance from
the main crash site (as every other explosive decompression I can think
of), there surely would have been some evidence of such a failure, and
none was found.

Karl Swartz	|Home
"The average dog is a nicer person than the average person."
  - Andrew A. Rooney