CPT Gurinder (Gene) Rana 6772271 <div class="images-v2-count-0"></div>What exactly is metal fatigue in the engine of a Boeing 777, especially post takeoff; doesn&#39;t engineering endure air worthiness of the plane before it is placed into service and; who is to blame? 2021-02-24T08:20:52-05:00 CPT Gurinder (Gene) Rana 6772271

<div class="images-v2-count-0"></div>What exactly is metal fatigue in the engine of a Boeing 777, especially post takeoff; doesn&#39;t engineering endure air worthiness of the plane before it is placed into service and; who is to blame?

2021-02-24T08:20:52-05:00 2021-02-24T08:20:52-05:00 MSG Private RallyPoint Member 6772320

<div class="images-v2-count-0"></div>Everything has a breaking point, whether it be people or objects. Perhaps no one is to blame.

2021-02-24T08:47:08-05:00 2021-02-24T08:47:08-05:00 SFC Melvin Brandenburg 6772678

<div class="images-v2-count-0"></div>sometimes things fail. Everything man made is going to fail eventually. But, nobody knows when eventually actually is.

2021-02-24T11:12:43-05:00 2021-02-24T11:12:43-05:00 LTC Jason Mackay 6772828

<div class="images-v2-count-0"></div>Could be a flaw in the titanium structure. Something mundane as a few degree temperature shift during the forging process (like a cold draft be opening a door). Could be a few thousands or tenths of an inch off tolerance during a very complicated 5 axis mill process (blades are curved in three dimensions and hollow. Titanium is challenging to machine and weld.) <br /><br />Everything has a statistical mean time to failure, but statistically there are outliers. Always are

2021-02-24T11:51:02-05:00 2021-02-24T11:51:02-05:00 SSG Bill McCoy 6773263

<div class="images-v2-count-0"></div>I am NOT an expert, nor am I a metallurgist. After the Army, I was the head of security for the largest Specialty Steel producer of stainless, titanium and other alloys used in aerospace, military and automotive applications. I do know that when those metals were produced, stringent testing was done prior to whatever metals were delivered to our customers. Just from our product brochures, it was also obvious that, in addition to testing, our end products sold were with information about expected lifespan as related to &quot;metal fatigue.&quot;<br /><br />That said, the fatigue can be a product manufacturing issue, or an issue with using the final product beyond it&#39;s intended lifespan. While there is always a area of &quot;between&quot; point A and point B, the recommended parameters in aerospace are pretty stringent. When components go beyond their maximum (point B) lifespan, &quot;fatigue&quot; becomes a major issue.

2021-02-24T14:57:56-05:00 2021-02-24T14:57:56-05:00 SFC Ralph E Kelley 6773591

<div class="images-v2-count-0"></div>I blame COVID-19. ~sarmark~

2021-02-24T17:21:50-05:00 2021-02-24T17:21:50-05:00 LtCol Robert Quinter 6774782

<div class="images-v2-count-0"></div>When an aircraft is designed, every part has an anticipated life dependent upon either the failure rate of similiar parts in similiar installations or the estimated life in the particular installation. The estimated life of a part is used to create the inspection or phased maintenance schedule of the particular model aircraft. Whenever a specific situation occurs where the stress on a part or system occurs, the &quot;overstress&quot; circumstance is reported and/or recorded and appropriate modifications to the inspection schedule are made. While every effort is made to anticipate problems, not all situations can be anticipated or failures predicted because of all the variables. In recognition of this, other systems are installed to indicate failing systems, but the fact is, failures will occur at unanticipated times and minimization of the damage falls on the ultimate safety system, the pilot. Even then, variables in training, retention of the training and unanticipated failures in the pilot system will occur (stroke, heart attack, et.) might occur to determine the outcome. Not everything can be predicted with so many variables.

2021-02-25T06:06:42-05:00 2021-02-25T06:06:42-05:00 LTC Ken Connolly 6775497

<div class="images-v2-count-0"></div>Over time heat and stress will weaken metal. Just like if you take a coat hanger and keep bending it back and forth. It will eventually break. There are tests that can be conducted on engine parts, but to do that the engine has to be disassembled.

2021-02-25T11:17:24-05:00 2021-02-25T11:17:24-05:00 SGT Clarence Gilbert 6809714

<div class="images-v2-count-0"></div>In the words of Forged in fire.... &quot;you had a crack that could not be seen&quot;

2021-03-09T17:26:54-05:00 2021-03-09T17:26:54-05:00 2021-02-24T08:20:52-05:00