Ingenieur Vol.81 January-March 2020 | Page 15

responsibilities much like a Professional Engineer with Practicing Certificate (PEPC) in Malaysia. Not many people outside the industry understand the details of the role of LAMEs in general. An aircraft operates within complex integrated mechanical and avionics systems, which are definitely not routine. Professionalism of CAAM Category B1/ B2 Type Rated LAME Quite a few years ago, there was a team of pilots, a license aircraft maintenance engineer (LAME) and flight crews, that needed to ferry a new aircraft from the manufacturing plant in the USA. They decided to ferry the aircraft back through the West Coast of USA, the Pacific Ocean and then into the Malaysian airspace. While cruising at an altitude of 43,000 feet, the cabin pressurisation systems failed suddenly. The risk of cabin occupants to experience hypoxia and anoxia that could lead to fatality was high. The back-up system kicked in, tapping the pneumatic source directly from the engine compressor stages to maintain cabin pressurisation. That was the first time the LAME saw how stress levels rose among the flight crews in such emergency situations. He immediately assessed the situation and analysed all available system parameters to define the systems problems. To mitigate the anoxia risk, the aircraft needed to descend to a lower altitude. However, that would mean more fuel will be burnt to overcome the higher drag at the lower altitude. As a result, there may not be enough fuel to reach the safe destination where they could ground the aircraft to solve this pressurisation system problem. Eventually, they landed on a small island called Majuro Island, which was part of the Marshall Atolls, in the middle of Pacific Ocean. In general, B1/B2 type rated LAME perform their duties within the scope of aircraft maintenance manuals, service bulletin, airworthiness directives, etc. However, more often than not, a B1/B2 type rated LAME also needs to perform tasks beyond normal routine. In this ferry flight, who would have expected a brand new aircraft, just out of production, ground tested, flight tested with all recorded data within acceptable limits, would have a critical pressurisation system failure? The LAME who had reached professional level understood that given the complexities of the mechanical and avionics of an aircraft, there is always possibility for failure for reasons such as design, workmanship and reliability. This is based on his education and training on the ability to define aircraft problems, conduct research, narrow down the research, analyse systems and parameters criteria, design/develop alternative solutions, make decisions and implement solutions. A solution was developed by the LAME with the manufacturer’s specialist team’s consent. The aircraft engineer verified the systems integrity with solutions. It was only then the LAME proceeded to carry out the certification that the aircraft and system is within its design and operational specifications as spelled out in the aircraft maintenance manuals and other documents. The team proceeded with the ferry flight with the solutions developed. It is a norm for B1/B2 LAMEs to carry systems deficiency research on many complex aircraft systems (especially intermittent system failure with the inability to duplicate the system faults on ground), locating the right information, applying theoretical knowledge and converting them into a solution. In this episode, the pressurisation problem was solved and the team continued on to Malaysia without further issues. They landed back in Subang Airport three days behind schedule but the designed and developed solution was safe and proven. The LAME’s subsequent recommendation included the design of a temporary solution which was forwarded to the aircraft manufacturer which made improvements to the systems. The inputs from this incident resulted in Cessna redesigning an improved air cycle machine systems overheat sensor with a new dash part number. Just recently, an aircraft landing gear system failed to retract and did an air turn back. After posing several questions to the pilot, the LAME defined the problem clearer, conducted research, narrowed down the research, analysed the criteria, found solutions, analysed solutions, made decisions and implemented corrective actions before carrying out the certification that the aircraft and systems is 13