Asci 609 - Aviation Maintenance Management

Aging Aircraft

Module 9 Activity 9.2 Research Paper

         John Doe

Embry Riddle Aeronautical University Worldwide

ASCI 609- Aviation Maintenance Management

In partial fulfillment for the Graduate degree

March 11, 2017

Instructor: Professor John Doe

Abstract

A constant concern for the aviation/aerospace industry is aging aircraft.  Many factors play an intricate role in the longevity of an aircraft.  Some factors that affect the life of an aircraft include materials, maintenance practices and the process in which the aircraft was made.  Hidden problems can occur from corrosion, brittle wiring and hair line stress fractures. These type of complications can make an aircraft dangerous and unfit for flight.  This research paper will cover problematic issues related to the dilemma of aging aircraft. Moreover, this research paper will include alternative actions and a recommendation to thwart the effects of time and promote aircraft endurance.

Table of Contents

      Abstract…………………………………………………………..2

1. Introduction………………………………………………………4
2. Problem/Issue…………………………………………………….4
3. Critical Factors and Examples……......………………………......5
4. Alternate Actions.......……………………………………………10
5. Recommendation.………………………………………………..11
6. References.……………………………………………………….12

1. Introduction

Aircraft have been soaring through the skies for a little over a century.  Of course, it could be argued that aircraft not resembling airplanes, did fly or float over a century ago.  However, for this research paper, discussions are of typical airplane type aircraft.

 Pioneers such as James S. McDonnell, William Boeing and Donald Douglas Sr. all built upon what the Wright brothers started, thus beginning the age of aviation and the issues that come with aircraft (Boeing, 2015).  Some of the same problems in early aviation, continue to this day in relation to the effects of perpetual time and use of aircraft.  Compromised airworthiness can result from corrosion, aged brittle wiring and stress fractures due to years of use and the increasing aircraft’s age.  

1. Problem/Issue

 Common problems aging aircraft can face involve the materials of the aircraft itself becoming corroded or brittle overtime.  The next segment of this research paper will clearly state the dilemma of aging aircraft symptomatically and break it down into key points.  

The problem is aircraft can have the following connected issues due to aging:

• Compromised Airworthiness

• Not fit for flight
• Reliability is a gamble

• Corrosion

• Hidden less obvious dangers
• Corrosion spreads and compromises structural integrity
• Corrosion requires treatment, repair or replacement

• Aged brittle wiring

• Possible arc issues
• Arcs may cause intermittent issues
• Combustible fluids and vapors may ignite from arc

• Stress Fractures

• Cracks weaken structural integrity
• Finding hairline cracks is often difficult
• Cracks require analysis and repair if possible

1. Critical Factors and Examples

The critical factors that are discussed in this research paper are all of the highest priority for maintenance managers, AMTs and the owners of the aircraft.  The most crucial factor is the danger of an aircraft catastrophe resulting in loss of life.  With luck, inspections may uncover aging issues within aircraft, yet it is often difficult to reach and inspect many areas of an aircraft. Wiring inside walls that are covered by paneling or under flooring may not be inspected for long periods of time.  Moreover, unless pilots or crew suspect issues such as glitches with equipment or smelling smoke, then hidden issues can go unnoticed until it is too late.  Also, unless found during an inspection, the AMTs will have no idea that there are stress fractures, corrosion or brittle wiring in the hollows of the aircraft.  Finding hairline stress fractures, corrosion and cracks is not an easy task, especially when these type of problems may be inside a wing or fuselage covered in sheet metal and riveted to the aircraft frame. A critical factor when corrosion, brittle wiring or fractures are found is the cost of repairing or replacing affected areas.  In some cases a repair may not be possible and results in a total replacement which may not be financially worthwhile to the aircraft owner.

 An example of an aircraft that had aging issues which resulted in an unfortunate deadly crash happen in 2005.  The infamous Chalk’s Ocean Airways flight 101 that had a failed main wing spar soon after taking off from Miami, Florida.  This resulted in the 58 year old plane losing its entire right wing in flight and the lives of those onboard. The investigation by the National Transportation Safety Board (NTSB), report AAR-07/04 found that the right wing parted from the seaplane because of numerous pre-existing fatigue fractures and cracks, which reduced the residual strength of the wing assembly (Skybrary, 2017).  Fig. 1 depicts the remains of the Grumman G73T Turbo Mallard Seaplane. [pic 1][pic 2]

Another example of an aircraft that was concluded to have aging issues which resulted in catastrophe was the Swissair Flight 111.   According to the Transportation Safety Board of Canada (TSB) executive summary, the reason the aircraft crashed was due to an electrical fire in the ceiling toward the front of the aircraft.  Above in Fig. 2, shows reconstruction efforts to piece together the wreckage to find what caused the crash.  It was concluded that wire arcing was the [pic 3][pic 4]

culprit, which started the fire and then ignited the flammable overhead paneling material that quickly engulfed in flames (TSB, 2013).  Unfortunately, even if the wires in question that arced and started the fire were inspected prior to flight, it is hard to say if the inspection would have revealed the brittle or chaffed areas along the wires. Below in Fig. 3, an image of typical aircraft wiring inside a large airplane.  At a quick glance, all looks well even though wiring problems can hide within the neat perfect looking bundles.  It is possible that the wires did not become dangerous until they had an electrical load or surge going through them, which broke

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