Aviation Authority Regulations

FAA Regulations for Aging Aircraft

As of November 2010 the major concern of Aging Aircraft was “widespread fatigue damage” (WFD). According to the FAA (Babbitt, 2010):

Fatigue damage to a metallic structure occurs when the structure is subjected to repeated loads, such as the pressurization and depressurization that occurs with every flight of an airplane. Over time this fatigue damage results in cracks in the structure, and the cracks may begin to grow together. Widespread fatigue damage is the simultaneous presence of fatigue cracks at multiple structural locations that are of sufficient size and density that the structure will no longer meet the residual strength requirements.

In the past to prevent this kind of damage the aircraft was supposed to be inspected regularly but due to accidents involving WFD this is no longer the case. Accidents involving AD’s created due to WFD will be discussed later in another blog post.

With the new rule involving WFD from aircraft aging two things are required as per Dorr & Duquette (2010):

• Aircraft manufacturers and certification applicants are required to establish a number of flight cycles or hours a plane can operate and be free from WFD without additional inspections for fatigue. Manufacturers have between 18 and 60 months to comply depending on the particular aircraft type.
• Once limits are established, operators of affected aircraft must incorporate them into their maintenance programs within 30 to 72 months, depending on the model of aircraft. After the limit is in the maintenance program, operators cannot fly the aircraft beyond that point unless the FAA approves an extension of the limit.

All of the limits of validity (LOV) are incorporated in the FAA Final Ruling on WDF. Of course these limits are capable of being extended but only under extreme scrutiny by the FAA.

EASA Regulations for Aging Aircraft

Currently there are still no regulations that the author was able to find in regards to EASA regulations for aging aircraft. There is a working document that currently available online mentioned in the references at the bottom of this blog that discusses aircraft aging and future regulatory requirements. Many of the recommendations gathered in the EASA document are due to the FAA assisting in creating this program. It does appear that there are plans on publishing a final document in second quarter of 2015.

References

Babbitt, J. R. (2010, November 15). Aging Airplane Program: Widespread Fatigue Damage; Final Rule. Federal Register. D.C., Washington, United States of America: Department of Transportation.

Dorr, L., & Duquette, A. (2010, November 12). Press Release – FAA Adopts “Comprehensive Solution” to Widespread Fatigue on Aging Aircraft. Retrieved June 17, 2014, from Federal Aviation Administration Web site: http://www.faa.gov/news/press_releases/news_story.cfm?newsId=12137

European Aviation Safety Agency. (2013, April 23). Notice of Proposed Amendment 2013-07. European Aviation Safety Agency. Cologne, Germany: European Aviation Safety Agency.