Aber dennoch, das Ausmaß wäre ziemlich heftig.
FAA Declares War Against ECi Cylinders
On August 12, 2013, the FAA published a Notice of Proposed
Rulemaking (NPRM) in the Federal Register for a proposed Airworthiness
Directive (AD) that would basically legislate more than 30,000 ECi cylinders
out of existence, forcing the owners of about 6,000 Continental IO-520,
TSIO-520 and IO-550 engines to perform $14,000 top overhauls. The total cost to
affected aircraft owners would be $83 million, making this one of the most
costly general aviation ADs in history. The FAA's rationale for this Draconian
AD is that they've received reports of 30 head-to-barrel separations in ECi
cylinders (out of a population of 30,000, a failure rate of 0.1%).
This proposed AD is one of the most unwarranted, inappropriate,
punitive and generally boneheaded rulemaking actions I've ever seen come from
the FAA. Here's why:
• At 0.1%, the reported head separation rate of
ECi cylinders is the lowest in the industry, lower than for Continental factory
cylinders. Why is the FAA picking on ECi jugs?
• There have been ZERO accidents and ZERO injuries
resulting from the reported head separations of ECi cylinders.
• Last February, ECi met with the FAA and
presented them extensive research data-from test-cell runs, torture testing of
the head-to-barrel junction, and finite-element modeling-demonstrating that the
head-to-barrel junction will not fail so long as CHTs are kept well-controlled.
ECi is convinced that the relative handful of separation failures are
operational problems (excessive CHTs) rather than a physical problem with the
cylinders themselves. I found ECi's data compelling. So did the NTSB. But the
FAA basically ignored it.
• Head separations are very rare, and when they
happen the result is generally pretty harmless. The head separates from the
barrel by less than an inch, the cylinder goes to zero compression, and the
engine continues to run on five cylinders and make roughly 80% power. (FAR Part
33 requires that all certificated piston engines must continue to operate
safely with one cylinder shut down.) The engine runs rough, and in a
single-engine airplane the pilot makes a safe precautionary landing at the
nearest airport (which is exactly what happened in every instance). In a twin,
the situation is even more benign-and the lion's share of reported failures of
ECi jugs occurred in Cessna 340s and 414s.
• The FAA's published Safety Risk Management
Policy (Order 8040.4A) [https://www.faa.gov/documentLibrary/media/Order/8040.4A%20.pdf]provides
an algorithm for assessing whether a particular safety risk is acceptable or
unacceptable, based on both the likelihood and severity of the risk involved.
When I plug the data about the ECi cylinder separations into the FAA's risk
assessment algorithm, the clear result is that these separations represent an
"acceptable risk" for which no mitigation is necessary. Obviously, the FAA
didn't follow its own policy when it decided to issue this proposed AD.
• In my opinion, the safety risk arising out of
the 6,000 top overhauls that would be compelled by the proposed AD is vastly
greater than the safety risk arising out of doing nothing. Over the past few
years, I have served as an expert witness in a half-dozen lawsuits involving
aircraft that fell out of the sky because of improperly performed top
overhauls. Several of these accidents were fatal. I feel so strongly about this
that I try very hard never to allow any of my managed-maintenance clients to
perform top overhauls.
Both AOPA and EAA have pledged to oppose this proposed AD
vigorously. A number of type clubs are also engaged. If the proposed AD is
allowed to take effect, it will set a terrible precedent that could ultimately
have implications far beyond ECi cylinders and big-bore Continental engines. Therefore,
I strongly urge every piston aircraft owner (whether you have ECi cylinders or
not) to submit comments to the docket opposing this NPRM. This can be done
The deadline for comments is October 11, 2013, so the sooner you comment the
better. It would also be helpful for you to send your comments to AOPA, EAA and
your type club.
