More Drama In Continental Engine Recall

Here are the big issues that owners want answered.

When Continental Motors recently issued a sweeping mandatory service bulletin (MSB) on many of its engines requiring the replacement camshaft gears, the issue seemed straight-forward enough. The gear, which reports to the FAA indicated was susceptible to fatigue and failure needed to be looked at soon and replaced soon.

It might not have been that simple.

The MSB calling for repetitive inspection and replacement of a cam gear in IO-470, IO-520 and IO-550 engines affects thousands of engines, and one media outlet/members group, Savvy Aviation, said that Continental had asked the FAA to issue an airworthiness directive (AD) that would have the weight of law in requiring owners to comply with the company's directive. Continental says that it did not ask for the AD to be issued but said it was working with the FAA on the issue of inspection and potential required replacement of the camshaft gear.

Concerned about what Savvy Aviation called a "draconian" and "potentially very costly action" a handful of member groups had what Savvy described as"an informal teleconference" with FAA representatives in order to share their concerns with the agency. Continental says that it was not invited to participate in the gathering.

On April 20th, Continental announced plans to modify the terms of its wide reaching service bulletin, so that the camshaft gear would require only repetitive inspective (every 100 hours) and replacement only at next overhaul unless it was found to be damaged at inspection time. The new plan also allowed for camshaft gear replacement without complete engine disassembly. The new proposal would save many owners the expense of inspections or engine removals for camshaft gear replacement. The modifications to the MSB were still not finalized as of early May.

Just how easy the new inspection process would be is a point of some contention. Continental represented the inspection as being something that would be a minor maintenance event, taking perhaps an hour or even less, and in some installations in some aircraft, that appears to be the case. In those planes, the mechanic can simply remove the starter adapter to inspect the cam gear. In other planes, according to Savvy, the inspection will require the lifting of the engine to make that inspection, which would be a time consuming and expensive event costing as much as $2,000 per inspection.

Savvy also makes the case that the inspection is unnecessary, that its survey of high-volume engine shops indicated that there "is no safety hazard associated with the older-style camshaft gears" that would warrant an AD or AD-style MSB.

Another point of debate is Continental's insistence that an engine be overhauled 12 years after its manufacturing date, advice that is not new but which is widely ignored by operators, most of whom rely on condition inspections and TBO values to make the overhaul decision.

At this point, it remains to be seen how the FAA will respond. Will it indeed issue an AD on the affected engines and if so, what will be the terms of that AD? If it chooses not to issue an AD, what will the final form of Continental's mandatory service directives?

We'll keep you apprised.


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A commercial pilot, editor-in-Chief Isabel Goyer has been flying for more than 40 years, with hundreds of different aircraft in her logbook and thousands of hours. An award-winning aviation writer, photographer and editor, Ms. Goyer led teams at Sport Pilot, Air Progress and Flying before coming to Plane & Pilot in 2015.

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