Discussion: Systems Safety Peer Review 3

Provide a classmate review on their discussion topic :

Based upon what you have read so far, the goal of systems safety is to develop a system with an acceptable level of risk. That is all well and good. However, in your opinion, what happens when we take a system, use it for a period of time then change the parameters of how we use it, or if we modify the system with new technology?

 

Classmate post that you need to post comment/ review on :

his is a very interesting discussion. EASA, the FAA or the CFO? How does the life cycle definition by EASA or the FAA relates to safety?

The mandatory documentation of LLP parts, Form One and 8130 are unbiased and useful to make decisions.

Although age is usually a good proxy, it is not always necessarily the case. When an aircraft is manufactured, several assumptions have to be made by the engineers, and not all of them can fit the same use of an aircraft. Ages, cycles, parts and type of operation are considered. For example, some DC-3 which have no pressurization, are examples of 70+ yrs old aircraft which are perfectly airworthy and safe. I fly one of them. The DC-3 can technically keep on flying as long as enough MRO (funding) is been allocated to it. It seems to me that except for specific life cycle limitations, the major one is a financial one which is called by companies CFOs. For example, British Airways a few years ago, decided to delay new airframes for sometime and refurbish older B747-400 purely based on costs. That was a decision based on economics which had no effect on safety. Imagine keeping an old B707 airworthy. No airline could stay afloat competing versus newer airframes and engines. Not to mention environmental and noise complaints!

Type and location of operation affects the life cycle of an aircraft. Aircraft operated in humid environments may have a shorter life span than those in dry ones, primarily due to corrosion and cracks.

Aloha 243 B737 , used for “Island hopping”, part of it fuselage broke in flight while at 24,000 feet. It had 89,680 cycles, and 35,496 flight hours.

The military has a different benchmark, where while costs are important, the financial platform is completely different. There is no shareholder (taxpayer) pressure to report healthy finances, no insurance to pay and resources tend to be usually available