Chapter 7 Post

This chapter talks about a MD-88 aircraft striking the approach end of a runway  with its main landing gear and narrowly escaping a catastrophe.  The NTSB found that one of the major contributing factors for this accident was the fact that the captain had contact lenses that weren't approved by the FAA for pilots.  These lenses created an optical illusion for the captain where he couldn't quite tell how fast he was descending.

Though mechanical failure was in no way to blame for this accident, there was an aircraft factor I found particularly interesting.  The crew had a vertical speed indicator that was labeled as "noninstantaneous."  This meant that the indicator could have a lag of up to 4 seconds before displaying accurate climb or descent rate.  The indicator could have been updated to show instantaneous rate if it was integrated with the inertial reference unit.  The NTSB determined that the lag time in the VSI also contributed to the accident.

Walters, J., & Sumwalt, R. (2000). Aircraft accident analysis final reports. New York: McGraw-Hill.

Air Detective Tips

The two major concepts that are talked about in the Air Detective Tips are the 5M and the Shell concepts. In this post I will go over them and how they are applicable to mechanical failures in aircraft.

The 5M concept is applied to accidents to help identify what causes an accident. The 5M's are Man, Machine, Mission, Medium, and Management (Lawin, R). With this model an investigator can bring these factors together to see which things may have worked together to cause an accident. Obviously in my paper I will be focusing on the machine part of this article.

Investigators can also use the SHELL model to better understand aircraft accidents. This model shows the interface between the human element or "liveware" and the surrounding elements (Lawin, R). The first example is liveware-software. This could mean training manuals or instructions. The next is liveware-hardware. This is how the human factor interacts with the aircraft and the mechanical parts of the aircraft. This is what I will focus on the most. The next one is liveware-environment and this encompasses environmental factors like weather or wind shear. The last is liveware-liveware. This happens a lot when there is a conflict amongst aircrew. Things like proper CRM could fall under this category.

https://erau.blackboard.com/bbcswebdav/pid-15077961-dt-content-rid-38727694_4/institution/Worldwide_Online/SFTY_UG_Courses/SFTY_330/Air_Detective_Tips/AirDetectiveTips9to12_0712.pdf

AD-13

This Air Detective tip talks about all the details that are scrutinized in an accident investigation.  Basically its a brief outline of each one of the factors that is looked at.  I have now been part of a couple major aircraft mishaps and I can tell you that investigators are thorough in looking at everything involved even if they already know the cause of the mishap.  Everything from aircraft forms to training records are seized and locked away and looked over.

Aircraft Accidents Caused by Mechanical Failure A brief overview

I chose my topic because it was something that really interested  me.  For me it is easier to read about an accident when no one is necessarily at fault and it is simple mechanical failure.  I also chose mechanical failure because it's one of the most common causes of aircraft crashes.  I picked this topic because as an aircraft mechanic myself, it is easy for me to understand and translate some of terms associated with this topic.

The truth of the matter is that about half of aircraft crashes occur from pilot error (Rohrer, F.,  Castella, T. 2014).  Unfortunately I believe that whenever an aircraft incident happens mechanics or mechanical failure is one of the first things blamed.  Throughout time it seems that pilots are always exalted.  Even I have been guilty of feeling the same way.  Even more unfortunately I have had two airplanes I have worked on go down.  One was because of a commonly know mechanical issue that was neglected and the other was just pilot error.  The instant I heard about each crash all I could think about is what could I have done wrong to endanger that aircraft.

Of course the whole purpose of investigating aircraft incidents is to prevent them.  If I get nothing else out of this class I will take what I learn here to make my workplace safer. 

Aircraft mechanical failure can be defined as a failure or break down in a mechanical aircraft component due to that component reaching the extent of its "age" or improper install or application. 

Pilot error is a decision, action or inaction by a pilot of an aircraft determined to be a cause or contributing factor in an accident or incident.

Here is a relevant link
http://www.bbc.com/news/magazine-26563806

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Rohrer, F., & Castella, T. (2014). Mechanical v human: Why do planes crash? Retrieved August 30, 2014.