Continental Motors on MSB05-8B
The publication of MSB05-8B has caused much speculation in the last few days. Some communications sent to the General Aviation Media community or directly to owners may have caused some confusion.
In late 2016 and early 2017, as part of the ongoing FAA Continued Operational Safety program, reports of camshaft gear fractures were provided to the FAA. A statistical assessment was accomplished by the FAA, and the initial data indicated an AD was merited. The FAA then asked CMG to reformat the current bulletin into a format compatible with FAA AC 20-176 to facilitate an AD. Continental Motors® subsequently superseded SB05-8A by MSB05-8B at the FAA request.
Our team is working on three main issues to alleviate the burden potentially imposed on aircraft owners and operators:
- Change the mandatory replacement of the camshaft gear to a visual inspection procedure allowing “on condition” operation until the engine is overhauled, replaced, or the gear is accessible.
- Change the time limit imposed by MSB05-8B, to values that still ensure that the appropriate level of safety is attained, but does not dictate a mandatory overhaul time limit.
- Publish alternative means of compliance, to allow camshaft gear replacement without complete engine disassembly.
Background information
Which engines are affected?
The following engine models are potentially affected:
- IO-470-U, V
- IO-520-A, B, BA, BB, C, CB, D, E, F, J, K, L, M, MB, N, NB, P, R
- L/TSIO-520-ALL
- LIO-520-P
- IO-550-A, B, C, D, E, F, G, L, N, P, R
- IOF-550-B, C, D, E, F, L, N, P, R
- TSIO-550-A, B, C, E
- TSIOL-550-A, B, C
How do I know if my engine is affected?
After checking the list of models potentially affected, please verify the following:
My engine was manufactured or rebuilt by the Continental Motors® factory after August 9, 2005.Your engine is not affected, if the cam gear was not replaced during other maintenance since the engine left the factory.
My engine was manufactured or rebuilt by the Continental Motors® factory before August 9, 2005.
Only engines manufactured or rebuilt at the Continental Motors® Factory before August 9, 2005, are potentially impacted by MSB05-8B.
My engine was manufactured or rebuilt by the Continental Motors® factory before August 9, 2005, and has been field overhauled since that date, or the case has been disassembled for any reason for a field repair.
Inspect logbook or other paperwork for indication of replacement of part numbers 631845, 655430, 655516, or 656031 by P/N 656818. If evidence is found that the original gear (P/N 631845, 655430, 655516, or 656031) was replaced by P/N 656818, document in logbook, no further action required.
Why issue an MSB mandating compliance within 12 years of manufacturing date?
Continental Motors® has always indicated that engines should be overhauled when reaching 12 years after manufacturing, factory rebuild or field overhaul or after reaching the TBO set for the engine. Although many owners operating under PART 91 choose not to observe this, we stand behind this recommendation. There are many parts, metallic or not (gaskets, O-rings etc.) that age with the engine. These parts need replacement after time in service or because age can modify their structure. The certification process ensures that an engine reaching TBO will not be adversely affected by engine run time or because of the aging of some materials. The fact that many planes are not hangared and are parked on a ramp, some in hot and humid or maritime climates, is also a factor to consider in the aging of airframes and engines.
Has Continental Motors® requested the FAA to issue an AD on this subject?
No. The FAA COS team reviewed the data related to these gear reports and performed statistical analysis. Their analysis showed that an AD was warranted and the FAA requested that CMGrewrite the related service bulletin in a format corresponding to FAA AC 20-176 to support the pending AD activity. Continental Motors® never requested the FAA to issue an AD.
Is it by design that Continental Motors® issued MSB05-8B twelve years after issuing SB05-8?
No. The fact that twelve years have passed between the original issuance of SB05-8 and MSB05-8B is purely coincidental.
AVIC International Holding Corporation was set up in 1979, with majority shares owned by Aviation Industries of China (AVIC). Headquartered in Beijing, the assets of AVIC International represent up to 280 billion RMB. The company has over 100,000 employees across 400 subsidiaries, is located in over 60 countries, and possesses eight publicly listed companies. AVIC International is a well-diversified company, with holdings in International Civil Aviation, Trade & Logistics, Retail & High-end Consumables, Real Estate and Hotel Management, Electronics Manufacturing, and Natural Resource Development. More information can be found at www.avic-intl.cn.
Continental Motors Group ™, Ltd. of Hong Kong, China is a subsidiary of AVIC International Holding Corporation of Beijing, China. Its mission is to provide advanced gasoline and Jet-A piston engine products, spare parts, engine and aircraft services, avionics equipment and repairs as well as pilot training for the general aviation marketplace. Continental is an international operation employing approximately 460 team members in Mobile, Fairhope and Miami, USA; 200 team members in St. Egidien, Germany; and 8 team members in Beijing, China. More information can be found at www.continentalmotors.aero.