[Industrial Standard] On the differences of airworthiness standards of piston engines in civil aviation (2)


The aero engine airworthiness regulation (CCAR33) promulgated in 1988 by CAAC Civil Administration of China is an integral part of “the Civil Aviation Regulations of China”. China's aero engine airworthiness standards mainly refer to the widely-applied Federal Airworthiness Regulations of the US. The original CCAR33 is equivalent to the 11th Amendment level of FAR33, which came into effect on 24th April, 1986. After two revisions to CCAR33 (see Table 1), the safety level of the up-to-date CCAR33-R2 is consistent with that of the 30th Amendment of FAR33 which entered into force on 2nd November, 2009. As for aero-piston engines, the revised results show that the safety requirements of the regulations are becoming higher and higher due to technological advances and growing maturity of the technologies involved in the products, mainly manifested as follows: On the one hand, the key parts of the aero-piston engine are not managed according to the life limitation, which means that the low cycle fatigue of the piston engine’s components can be designed for infinite life. On the other hand, it is required that the rotor casing must be inclusive of the rotor (including blades and disks), which means that the piston engine will not have non-containment events of high-energy rotor debris.

4、Similarities and differences of airworthiness standards in different countries

In the late 1980s, FAA and JAA helped set up CAAC’s engine working group and gradually promoted the unification of European and American airworthiness standards. It was remarkably well-received from 2007 to 2009. From the statistics and reasons of amendments issued by FAA within merely two years, FAA has promulgated 10 amendments, revising nearly 40% of the provisions of FAR33, mostly due to the need to unify European and American provisions. It is rare to see so in the history of the standard revision, which is enough to demonstrate the determination to unify the FAA and EASA standards. The safety level of the currently valid CCAR33-R2 corresponds to the 30th Amendment of FAR33. For the piston engine, the FAR33 Amendments 31, 32, 33, and 34 have not been revised. In other words, CCAR33-R2 is equivalent to the 34th Amendment safety level of the currently valid FAR33.

Up to August, 2016, the differences in the airworthiness requirements of the currently valid CCAR33-R2, FAR33-34 and CS-E change4 for aero-piston engines are shown in Table 2, with the exception of the different airworthiness standards in the table, the other provisions being unified.