On Wed, 18 Apr 2018 12:12:41 -0400, "Mr. Luddite"
wrote:

On 4/18/2018 11:26 AM, wrote:
On Tue, 17 Apr 2018 17:18:09 -0400, "Mr. Luddite"
wrote:


Sadly one passenger was killed and others injured when the engine on the
Southwest 737 failed today.

The turbine blades in jet engines are under stress and heat during
operation and are the usual failure mode in cases like this.
There is a "containment ring" that is supposed to prevent the flying
turbine blades from damaging the aircraft but it appears that it didn't
capture all the flying parts today.

Heard the head of the NTSA state that this failure happens "3 or 4 times
a year".

It isn't confirmed yet that turbine blade failure is the cause of this
particular event but it most likely is.

We built a system for Pratt and Whitney back in the 80's to deposit
thin film strain gauges and thermocouples (temp measurement) on the
turbine blades for real time operating monitoring of the turbines.

Here is a little more about that engine failure
https://www.avweb.com/eletter/archives/101/4022-full.html?ET=avweb:e4022:323843a:&st=email#230684



Sounds like when that turbine blade snapped it went in a direction that
missed the containment ring.

Those blades used to be a nickel/titanium alloy. I've read that some
are now made of a metal/ceramic. They are under high stress and high
temperatures.

Looking at that picture, the ring may have come apart too. I assume
that jagged metal was the ring. It is clear that engine pretty much
disintegrated from the inside out. When you think about the forces on
a jet engine, it is amazing that they work at all.
Here is an interesting conversation about fan tip speeds and RPMs but
only the intellectually curious will enjoy it.

http://www.airliners.net/forum/viewtopic.php?t=741473

BTW if you don't subscribe to AvWeb you might want to. That is a place
to get aviation news written for pilots, not just the normal folks.
They usually get to the bottom of incidents like this better than the
media at large.