Yesterday I had a chance to attend a seminar which organized by Hong Kong Institution of Engineers (HKIE), Aircraft Division. The seminar was held at HK Polytechnic University and presented by one of an engineer from Cathay Pacific Airways, Mr. Kanagasabai. Although my job is not directly related in Aircraft Maintenance Schedule, but this topic appeal to me since once in a while I also dealing in setting up requirement for continued airworthiness for aircrfat maintenance schedule. Furthermore, the aircraft maintenance Schedule contributes and plays an important aspect of ensuring the safety of an aircraft.
What is Aircraft Maintenance Schedule anyway? Just to give you an example, when you buy a new car, you will receive a booklet which contains a set of instructions on how to maintain your car. The booklet will tell you when you need to change the oil, filter, battery, gasket or even check some car components on certain mileage. So this concept also applies to an aircraft. In aviation, an operator(airline) will have a document named an Aircraft Maintenance Schedule which contains the list of maintenance task that need to be done on certain period of time. Normally the frequency of the inspection interval is specified by flying hours, flying cycle (how many times aircraft take off and landing) and also month/year. Why it is important? Well, if you miss to do the required maintenance task within specified time, then you will miss to detect if there is any alarming damage on the aircraft at early stage and also you will not be able to fix it. Subsequently, the problem only visible during flight and may caused complicated and worst case scenario.
Look what happened on Alaska Airlines Flight 261 disaster which occured not so long ago in 2000. Alaska Airlines Flight 261, a McDonnell Douglas MD 83 aircraft crashed into Pacific Ocean near Anacapa Island, California killing all 88 people on board. The subsequent investigation revealed that the jackscrew which controlled the tail horizontal stabilizer had been improperly maintained and lacked proper lubrication causing the jackscew to jam and become unmovable. If you are not in aviation industry, the horizontal stabilizer is the aircraft part, like a small wing on the aircraft tail. When the investigator issued its final report it noted that shoddy maintenance at the airline was the reason for a lack of grease on the horizontal stabilizer jackscrew which contributed to excessive wear and the eventual failure of the jackscrew. Why there was no sufficient lubrication? The answer is Alska Airline progressively increase the interval of their maintenance schedule withour proper engineering data and subsequently they missed the maintenance task to put a grease on the jackscrew.
If you missed to change your battery car, you might be still ok as the worse thing can happen to you is the car will breakdown on the road or in the middle of the highway. You just need to call a mechanic or tow your car to the workshop. But it will not be the same case for an aircraft which flying at 35, 000 feet above the ground. No one can predict what will happen then if there is catasthrophic failure occur on the flight. So, we should strictly do the right things at the first place rather than waiting the problem occured during flight. In another word, stick and follow the aircraft maintenance schedule without skipping it…
Ir. Edie Noreffendi
27 Nov 2013